Cub Cadet 769-05905 Lawn Mower User Manual
Contents
1. o gt si S d NOTE Use care not to over tighten the O ring fittings damaging the O rings NOTE The lines may be installed finger tight to establish their positions then tightened fully 5 34 Install the belt tension arm spring steering link age 5 35 Install the fan washer and nut to the input shaft Torque the nut to 240 inch lbs 5 36 Install the debris screen CHECK THREADS CHECK TAPERED SEATS 5 37 Check the fluid level in the reservoir purge the Figure 5 27 system as described in the test instructions 5 38 If the hydraulic system has been drained and 5 28 Prior to installation pour oil directly into the flushed with 20W50 install a new filter and fol pump inlet and high pressure ports then trans low the instructions for refilling the hydraulic sys fer yellow plugs back to the replacement pump tem in the Operator s and Service Manual M48 Tank 5 39 Install the wheels lower the TANK to the ground and test run it in a safe area Make any neces sary adjustments before installing the cutting deck 10 6 2 6 3 6 4 6 5 6 6 6 7 6 8 REPLACING THE HYDRO MOTOR If the cutting deck is currently on the unit remove it Safely lift and support the rear of the tank Remove the rear wheels using a 3 4 socket Tilt the seat up and disconnect the negative bat tery cable Thoroughly clean the area surrounding any hydraulic fittings to be loosened or rem2. Cub Cadet M48 Tank IMPORTANT READ SAFETY RULES AND INSTRUCTIONS CAREFULLY This Service Manual is not a substitute for the Operator s Manual You must read understand and follow all of the directions in this manual as well as the Operator s Manual before working on this power equipment CUB CADET LLC P O BOX 361131 CLEVELAND OH 44136 0019 PRINTED IN USA FORM NO 769 00966 11 2003 TABLE OF CONTENTS WE en 1 POO UT TIS S CCU O WE 1 CHIANG SS TOROS and OA E 1 Drive System AGIOS IMG EEN 1 YNO ag gn ool oko ate DE 4 Hyd PUMO REDIACEMEIMN einser a A A 6 Hydro Pump Motor Replacement ccccscccseccsececeeeceeeceesecseeseeeseueenseesseesees 10 Brake Linkage Adiusiment 13 VR Eu 16 EE EE Eeer 19 Sisi RE 23 Re iere EE 26 M48 Tank M48 Tank The hydraulic fluid level should be at the second hole in the filler neck of the reservoir See Figure 3 3 1 ABOUT THIS SECTION CC The M48 is part of the Cub Cadet Commercial Tank Series The 2004 model year M48 is very similar to The 2001 model year Tank Earlier versions of this machine have been covered in the 2001 Cub Cadet Commercial Technical Handbook Form 770 10528 2 CHANGES FOR 03 AND 04 e New hydro motor frame assembly e New hydro motors e New brakes and brake linkages e Finer increments of height adjustment e Different choice of engines Features of the 72 TANK The content of this section is intended to detail
3. Check for and repair any leaks Check the fluid level in the hydraulic reservoir Top it up if necessary Continue to operate the drive system to warm up the hydraulic fluid NOTE Performing the test with cold fluid will make a significant difference in the flow readings obtained The test will not be valid M48 Tank 4 23 When the fluid is between 160 210 deg f 71 90 deg c apply full forward drive pressure to the lap bar with the engine running at full speed 3600 RPM while an assistant closes the valve to the point where pressure reaches 300 PSI 21 Bar See Figure 4 23 CONTROL CONSOLE INSET 3600 RPM wee tt ie CLOSE VALVE TO BUILD PRESSURE Figure 4 23 300 PSI NOTE It may be necessary to over shoot 300 PSI slightly then open the valve to reduce pres sure to 300 PSI 4 24 Take note of the reading on the flow meter por tion of the test kit when the pressure gauge reads 300 PSI 4 25 Continue closing the valve until the pressure reading reaches 1 100 PS I 76 bar Take note of the flow reading See Figure 4 25 1100 PSI VALVE CLQSED Figure 4 25 4 26 Subtract the 1 100 PSI flow reading from the 300 PSI flow reading The resulting figure is called flow droop 4 27 4 28 4 29 4 30 DZ 9 3 5 4 5 5 Interpretation flow droop greater than 1 5 GPM indicates a pump that is not performing as well as it should NOTE A blocked filter may accoun
4. Figure 6 13 PRESSURE A COTTER 6 14 Remove the four sets of nuts and bolts that hold the hydro motor to the hydro motor frame assembly using 3 4 wrenches 6 15 Lift the motor slightly and carefully pull it out far enough to remove the motor plate from the end of the four bolts See Figure 6 15 Figure 6 11 6 12 Place a catch pan under the hydro motor and have two 1 2 JIC plugs within reach Figure 6 15 NOTE The hydro motor weighs nearly 50 Ibs 11 M48 Tank 6 16 Withdraw the hydro motor along with the three motor spacers and place them gently on a work bench See Figure 6 16 Figure 6 16 6 19 6 20 Safely fixture the hydro motor and brake assem bly in a minimum 20 Ton press so that the ram presses against the end of the axle and the assembly is supported by the edge of the brake drum Press the drum off of the tapered shaft Remove the castle nut and brake drum from the axle See Figure 6 20 ORIENTATION MARKS 6 17 If the brake is to be removed remove the clip ASSEMBLY fon 0 that holds the brake arm on the splined shaft and mark the location of the brake arm on the Figure 6 20 splined shaft 6 21 Mark the orientation of the brake assembly on Figure 6 17 6 26 6 18 Remove the brake arm from the splined shaft NOTE The Hydro motor can be ordered with or without the brake assembly If an appropriate 6 27 size press is not available the dealer should consider
5. changes in service techniques that have occurred since the introduction of the M Series DRIVE SYSTEM ADJUSTMENT 3 1 Prior to making any adjustments to the drive sys tem inspect the hydro control linkages drive belt brake linkage tires fluid and filter 3 2 The hydraulic reservoir and filter are accessible beneath the seat See Figure 3 2 h fi e OIL FILTER m BATTERY Figure 3 2 3 4 FIRST HOLE 5 a Az D FLUID LEVEL wee Figure 3 3 NOTE It is very important that the hydraulic oil does not become contaminated Clean the sur rounding area thoroughly prior to opening any part of the hydraulic system NOTE The hydraulic drive system contains roughly 3 25 gal of SAE 20W50 motor oil having an API rating of SJ CD or better Hydraulic Drive System Fluid Plus P N 737 3121 gal is an acceptable premium alternative NOTE Complete draining and filling instructions are contained in the Operator s and Service Manual Tracking is effected by the circumference of the rear tires and the amount of drag produced by the front tires Rear tire pressure may be adjusted within the range of 8 10 PSI to achieve equal rear tire cir cumference Front tire pressure should be within the range of 20 25 PSI M48 Tank 3 5 For complete brake adjustment procedures 3 7 refer to the Brake Adjustment section of this manual For the purpose of tracking insure that the brake l
6. 2 9 3 9 4 M48 Tank The TANK exhaust systems all feature a new aluminized finish This finish resists corrosion better than the heat paint that is more commonly used It also dissipates heat more effectively producing noticeable improvements on chassis dynamometers See Figure 9 3 x 5 Ne Figure 9 3 Some features of the 72 deck have been extended throughout the TANK model range Looking at the 60 model as an example these features include More easily adjustable hydro control link See Figure 9 5 Figure 9 5 M48 Tank 9 6 1 4 increments on the height adjuster with foot See Figure 9 6 assist deck lift Figure 9 6 9 7 The deck belt release operates in a vertical plane It can be tensioned with foot pressure and the rear wheel does not interfere with its travel See Figure 9 7 Figure 9 7 20 9 8 Heavy duty spherical rod ends on the arms at the front of the deck See Figure 9 8 a Ss Eat Kr weg Br Figure 9 8 9 9 The arms themselves are cast iron and the lift shaft is heavier See Figure 9 9 Figure 9 9 9 10 The deck itself features reversible caster wheel 9 11 brackets The same part number applies to both the left and the right brackets See Figure 9 10 H IMAND CUT SYSTEM Figure 9 10 Improved self aligning pillow blocks now sus pend the deck See Figure 9 11 Figure 9 11 21 M48 Tank 9 12 The
7. NUTS AM NUTS BRAKE CONNECTOR RODS Figure 7 7 7 8 Remove the hairpin clip that secures the brake link rod to the brake arm on the brake assembly 7 9 Repeat on other side 7 10 Disconnect the brake link rods left and right see Figure 7 10 ep BRAKE LINK ROD Figure 7 10 14 7 11 Remove the hairpin clip and clevis pin that secures the clevis on the end of the brake con nector rod to the rear brake arm assembly on both sides See Figure 7 11 BELLECRANK SHAFT i BRAKE LINK 4 ROD Tt f REAR BRAKE ARM ASSEMBLY CONNECTOR ROD Figure 7 11 7 12 Confirm that the rear brake arm assembly moves freely on the rear bellcrank shaft is suffi ciently well lubricated and is free from excessive play caused by worn busings See Figure 7 12 Figure 7 12 NOTE If rear brake arm assembly service is needed the rear bell crank shaft that the arms pivot on can be easily removed by unbolting the brake shaft holders removing the cotter pins and washers that locate the brake arm assem blies on the shaft NOTE Both washers that fit next to each rear brake arm go between the arm and the cotter pin 7 13 Confirm that the brake bearing hub brake han dle and the brake rod that connects them move freely on the front bellcrank shaft 7 14 Confirm the position of the brake bearing hub the top of the arm that the brake rod to the brake handle connects to
8. Ohm reading across the terminals of the oil temperature sensor should be in the 2375 2625 v range In order to coordinate the timing of the fuel injec tor triggering as well as tune the fuel delivery and ignition timing to match the load applied to the engine the ECU needs to know the speed that the crankshaft is spinning and the position of the crankshaft There is a 60 tooth ferrite ring gear on the fly wheel This ring gear is separate from the starter motor ring gear A Hall effect pick up mounted 049 069 from the ring gear gener ates a pulse as each tooth passes by The ECU counts the pulses to determine engine RPM There are two consecutive teeth missing from the ring gear The ECU gets a signal from each of the present teeth every 6 degrees of crank shaft rotation The 12 degree gap is positioned 84 degrees before cylinder 1 reaches TDC This tells the ECU where the engine is in terms of piston position Each time the engine is started it will take 720 degrees of crankshaft rotation for the ECU to find the piston and begin working Comparing engine speed to throttle position the ECU can interpolate the engine load If the cranks trigger signal fails to reach the ECU the engine will not run Crank triggers are generally an all or nothing proposition they work perfectly or not at all In extremely rare instances a failed crankshaft trig ger will not keep up with the speed of the engine It will wo
9. filter may damage filtering medium NOTE Fuel filters should be replaced at regular intervals specified in the Operator s Manual A blocked fuel filter puts extra load on the pump creating extra heat This may lead to shortened fuel pump life Fuel pumps are much more expensive than fuel filters A blocked filter may not present symptoms until the blockage is sub stantial enough to damage the fuel pump 10 10 After the filter the fuel reaches the fuel rail The fuel rail feeds the injectors See Figure 10 10 M48 Tank A Cap for shradg valve a i gt e mane Pla Sr ac connection for injecto A Wi eg a Ow H E Ze SS Te Fuel injetor gt d e Ce E j z 0am Figure 10 10 10 11 The shrader valve can be used for checking fuel pressure Fuel pressure readings obtained at the shrader valve can help pin down problems with the fuel pump or the fuel pressure regulator See Figure 10 11 kd gt Figure 10 11 10 12 Before any service is performed on the pressur ized portion of the fuel system the engine must be allowed to cool and the pressure should be relieved 10 13 To relieve pressure from the fuel system e Turn the key switch off e Remove the 10A in line fuse that protects the fuel pump e Start the engine normally It will run for only a few seconds e Turn the key switch off 26 11 EFI CONTROLS The Fuel injection syst
10. ordering hydro motor with the brake assembly attached 12 6 22 6 23 6 24 6 25 the hydro motor Remove the four socket head cap screws that hold the brake assembly to the hydro motor using a 1 4 allen wrench Transfer the four mounting bolts from the old hydro motor to the new one Replace any that show signs of wear or damage Position the three motor spacers on the bolts and install the hydro motor in the TANK Place the motor plate over the end of the bolts apply Loctite 242 blue the the bolts and install the four nuts Tighten the bolts to 450 550 in Ibs Inspect the brake assembly If there are not signs of significant wear or damage install the brake on the new hydro motor using the match marks to maintain the same orientation Use new lock washers and or Loctite 242 blue when installing the brake assembly Torque the socket head cap screws to 160 200 in lbs 6 28 6 29 6 30 6 31 6 32 6 33 6 34 6 35 Install the brake arm and clip on the new hydro motor See Figure 6 28 Figure 6 28 Transfer the O ring to flare adaptor fittings from the old hydro motor to the new hydro motor using a 1 wrench Inspect the fittings and O rings If there is any doubt about their condition replace them Lightly lubricate the O rings with oil on assembly Apply a small amount of anti seize compound to the taper of the brake drum and install the brake drum on the axl
11. should line up directly with the parking brake switch and the brake rod should be parallel to the frame When this is true the front brake connector rods should also be parallel to the frame See Figure 7 14 BRAKE lt A HANDLE BRAKE ROD BRAKE BEARING HUB Zei Figure 7 14 7 15 If adjustment is necklaces loosen the two collars on the front bellcrank shaft using a 1 8 allen wrench Re position the bearing hub and collars as necklaces and tighten the collars See Figure 7 15 COLLAR BRAKE BEARING HUB Figure 7 15 NOTE The left edge of the brake bearing hub will usually be even with the inner edge of the frame when correctly adjusted M48 Tank 7 16 Check the brake arm on the brake assembly for freedom of movement It should return to center 7 17 Reconnect the brake link rods and brake con necting rods to the rear brake arm assemblies 7 18 Apply light rearward pressure to each brake con necting rod The clevis pin at the rear end of the rod should just contact the back of the hole that it passes through to connect the clevis to the rear brake arm assembly 7 19 Loosen or tighten the nylock nut at the front of the connecting rod to bring the heavy spring lightly into contact with the brake bracket See Figure 7 19 J CIENT FORC T ADJUST RETURN SPRING HERE Figure 7 19 7 20 Apply the parking brake The gap between the bottom edges of the brake bracket and the c
12. Running dry will damage the pump NOTE The fuel pump will run briefly each time the key switch is turned on This pressurizes the system If fuel pressure is absent and the fuel pump cannot be heard when the key switch is turned on the fuel pump may not be getting electricity Check for power before condemning the fuel pump 24 10 7 NOTE The fuel pump is protected by an internal 60u filter The pump sends pressurized fuel to the fuel pressure regulator The regulator maintains a constant down stream pressure of between 36 and 42 PSI See Figure 10 7 Fuel pump Fuel pressuref j regulator Figure 10 7 NOTE High pressure fuel lines SAE R9 rating and Oetiker style hose clamps must be used between the fuel pump pressure regulator fuel filter and fuel injector rail CAUTION Substitution of fuel system compo nents that are not capable of handling the pres sure generated by this fuel system will lead to rapid failure of those components Component failure hose clamps filter etc in the high pressure portion of the system poses a signifi cant fire hazard 10 8 There are two lines exiting the pressure regula tor One is a regulated pressure line that feeds the fuel rail via the fuel filter The second line is a return line The third line is a high pressure feed from the fuel pump See Figure 10 8 Regulated pressure to rail via filter Vacuum barb P not used Ni A Vu D f
13. anks should pivot easily without too much play The rods should not be bent and the rod ends should not be loose NOTE The rod end and jam nut at the rear of each connector rod have left hand threads A lock washer is placed between the control input arm on the hydro pump and the rod end NOTE The rod end and jam nut at the front of each connector rod have right hand threads A spacer fits between each control hub assembly bellcrank and the front rod end that connects to it e The return to neutral cylinders should both work as advertised See Figure 3 13 3 15 RETURNTO NEUTRAL E CYLINDER RIGHT en I mg Figure 3 13 NOTE Remove the control console to gain access to the return to neutral cylinder 3 14 3 16 3 17 M48 Tank Loosen the jam nuts at each end of the hydro control link rods and rotate the rods to lengthen or shorten them See Figure 3 14 Figure 3 14 Start the engine and release parking brake to test then turn the engine off to make the adjust ment Tighten the jam nuts against the rod ends when adjustment is complete and make a final test to confirm After neutral control is correctly adjusted set the travel stops to achieve correct tracking and adjust the lap bars for operator comfort See Figure 3 17 zl LAP BAR BW MouUNTINe d BE LAP BAR TRAVE te STOP BOLT Figure 3 17 NOTE The clamp bolts for the lap bar mounting handle can be use
14. d can cause seri ous burns WARNING Release of pressurized hydraulic fluid can cause serious of fatal injury Open the relief valve on the hydro pump that is to be tested This will relieve any residual hydraulic pressure Confirm that the hydraulic pressure has been relieved by rotating the brake drum hub assem bly If the it will not rotate confirm that the brake is released and that the brake linkage is not bound Install a 1 2 JIC double male coupler in one end of the 18 hydraulic line in the test kit Install a 90 deg 1 2 JIC double male elbow in the other end See Figure 4 8 1 2 JIC COUPLER 18 HYDRAULIC LINE Figure 4 8 Position a catch pan beneath the hydro motor Have the hydraulic pressure and flow test kit and two 1 2 JIC plugs within reach NOTE The fittings on the ends of the test kit are all 1 2 JIC Disconnect the upper line from the hydro motor and quickly install a 1 2 JIC plug in the line It only needs to be finger tight 4 11 4 12 NOTE The test can be performed at either line between the pump and the motor The top line on the motor is the in line from the pump when driving forward The linkage has more travel in forward than it does in reverse so the test is most easily done on the top line of the pump driving the pump in the forward direction for ward Connect the flow meter end of the test kit to the hydro motor Remove the plug from the line c
15. d to adjust the amount of force required to move the lap bars into or out of the neutral slot M48 Tank 3 18 If one side does not drive as effectively as the 4 1 4 2 4 3 other test the output of the hydro pump to deter mine if the problem lies in the pump or the hydro motor By the process of elimination if perfor mance is lacking brake drag is eliminated adjustment is correct and the pump is O K then the problem is the motor Pressure and flow tests will be used to determine if the pump is the the source of the problem TESTING HYDRO PUMP OUTPUT NOTE The log splitter hydraulic test kit is used for this set of flow and pressure tests Safely lift and support the rear of the M48 If the cutting deck is currently on the unit remove it Remove the rear wheels using a 3 4 socket see Figure 4 3 BRAKE DRUM HYDRO MOTOR Figure 4 3 NOTE The fittings on the lines that connect the hydro pumps to the hydro motors are 1 2 JIC NOTE 7 8 and 13 16 wrenches will be needed for this test A 1 wrench may be needed to hold the connector that joins the JIC line connection to the O ring connection on the hydro motor 4 4 4 5 4 6 4 7 4 8 4 9 4 10 Thoroughly clean the area surrounding any hydraulic fittings to be loosened or removed If the unit has been run recently allow it to cool before doing loosening any hydraulic fittings WARNING Hot hydraulic flui
16. deck support plates are larger this year to prevent plate bending and separation See Figure 9 12 Figure 9 12 9 13 The baffling airflow and strength of the deck have all received some improvements this year 9 14 The trailing edge of the discharge opening has been swept back and the bar that prevents foot penetration has been modified Both changes improve strength and airflow See Figure 9 14 Figure 9 14 M48 Tank 9 15 A guiding baffle near the rear of the opening 9 17 The under deck baffling has been reinforced helps direct the clippings out from under the and a stealth baffle has been added between deck See Figure 9 15 the second and third blades See Figure 9 17 Ti AI EEN a awe Ses gt SS Seon eee ee ee ai A gf MEE BY ay Co DN ae Ki Wi OR ted gt T wii Figure 9 15 Figure 9 17 9 16 The addition of a California Gap at the leading edge also improves airflow and products the internal shape of the deck from damage if some thing is hit hard enough to bend the reinforced leading edge See Figure 9 16 Figure 9 16 22 10 KOHLER EFI Fuel injection is nothing new The Wright flyer that made history above the dunes at Kitty hawk North Carolina was fuel injected That was a hundred years ago this past summer That system was only slightly more complex than a cam driven Windex bottle All diesel engines are fuel injected though the principles of operation are considerably d
17. e Install the castle nut on the axle and lock it with a fresh cotter pin Connect the brake linkage Install the rear wheels and torque the lug nuts to 50 70 ft Ibs Check the fluid level in the reservoir purge the system as described in the pressure and flow test instructions NOTE If the hydraulic system has been drained and flushed with 20W50 install a new filter and follow the instructions for refilling the hydraulic system in the Operator s and Service Manual Install the wheels lower the TANK to the ground and test run it in a safe area Make any neck laces adjustments before installing the cutting deck M48 Tank BRAKE LINKAGE ADJUSTMENT With the TANK parked on firm level ground lift and safely support the back of the unit Remove the hairpin clips that hold the floor panel in position Lift the floor panel up using the grip opening at the top rear edge slide it to the left and remove it See Figure 7 3 1 4 7 5 7 6 13 Figure 7 3 Release the hydro relief valves and release the parking brake Rotate each wheel to confirm that the brakes are not dragging or binding Remove the rear wheels using a 3 4 socket NOTE It may be necklaces to set the parking brake while loosening the lug nuts M48 Tank 7 f Loosen the jam nut that locks the shoulder nut in position on the brake connector rod using a 9 16 wrench and a 3 4 wrench See Figure 7 7 SHOULDER
18. e ECU is the brain of the engine control sys tem It is very durable but there are some rules to follow in order to avoid damage to the ECU If you diagnose a faulty ECU do not replace it without calling Cub cadet Technical Support for specific handling instructions Previously mentioned do not use a conventional test light to look for power in the engine control circuit Previously mentioned do not disconnect any electrical devices while the engine is running Do not reverse the battery terminal connections M48 Tank Do not connect a battery charger to the TANK with the key switch turned on The ECU requires at least 7 0 volts to function If the battery goes dead or is disconnected the adaptive memory in the ECU will be cleared It will take 10 15 minutes of running at normal operating temperatures under a variety of loads and throttle settings to re learn the full envelope of performance Clearing the memory will also clear diagnostic trouble codes The ECU receives signals from a variety of sen sors These include crankshaft speed and posi tion throttle position engine temperature oxygen content of the exhaust gas battery volt age There is an indicator light that flashes diagnostic codes in the event that there is a malfunction If the signal from any of the sensors are not in the range that the ECU is expecting from compari son to its adaptive memory a code will flash In the event of a malfunct
19. e offered by fuel injection have not been worth the expense that they add to out door power equipment Fuel injection systems have become less expensive and more dependable in the past two decades At the same time commercial turf equipment in specific and outdoor power equipment in general have become more sophisticated and more expensive Performance and expectations have improved The final factor is the increase in the price of fuel All of these factors combine to make EFI worthwhile for some applications The improved fuel economy reduces fuel expense for heavy Commercial users It also increases range requiring fewer stops to replenish fuel 23 M48 Tank 10 1 For 2004 one model of TANK will be offered with a Kohler 28 H P EFI engine That unit is a 60 Wide Track model That model is built on the widened M72 frame but features a 60 deck 10 2 The fuel injection system used on the the Kohler powered TANK uses a high pressure electric fuel pump The pump generates 3 bars of pressure roughly 40 PSI and is capable of moving 25 liters per hour of fuel This is more fuel volume than the engine will consume but it is necessary in order to maintain pressure under all fuel demand conditions 10 3 Because there is more fuel supplied to the injec tors than the engine will consume return lines route the excess volume back to the fuel tanks See Figure 10 3 Left fuel tank 1of2 l gt er Fuel
20. em used by Kohler is an adapted version of the Bosch Motronic automotive sys tem 11 2 11 3 NOTE Do not connect or disconnect any electri cal components with the key switch in the on position The resulting arc could cause immedi ate and sever damage to the ECU NOTE If using a circuit tester use only a high impedance tester eg Thexton model 125 Conventional testers pass the current they are checking through a small incandescent bulb In some cases the bulb draws more power than the circuit in the computer over loading the cir cuit and complicating the diagnostic process by inducing a circuit failure High impedance testers do not actually pass much current and the LED indicator will not draw enough power to damage the circuitry See Figure 11 0 P gr ae HIGH IMPEDANCE E tl COMPUTER CIRCUIT TESTER ez The EFI engine has a throttle valve or air valve similar to that of a carburetor There is no fuel mixed into the air at this point The throttle valve only regulates the amount of air that enters the engine The throttle responds to the governor just like it would with a carburetor The computer ECU takes in information from various sensors and decides how much fuel the engine should have to maintain a correct fuel air mixture The ECU then sends electrical pulses to the individual injectors triggering them to spray fuel into the intake tract 11 4 11 6 The fuel pre
21. ifferent Electronic fuel injection is not an especially recent development either In 1956 Chrysler marketed the first car with electronic fuel injection The fuel injection system used was made by Bendix and was called The Bendix Electrojector System It was operated by a large Electronic Control Module that took up most of the trunk The ECM used relatively delicate tubes generated a lot of heat and was susceptible to mois ture temperature changes vibration and shock Most of these systems were discarded and the cars retrofit ted with carburetors There were mechanical gasoline fuel injection systems on the market before the Bendix system was intro duced Rochester and Bosch were fairly prominent The auto industry made the transition to electronic fuel injection in the 1970s and 80s in response to emission control and fuel economy standards Even the best tuned carburetion system only offers and approximation of the correct fuel mixture for any given operating condition They can be tuned to provide sweet spots but generally cannot maintain an ideal mixture for all speeds loads temperatures and condi tions Carburetors also cost efficiency by working the air the venturi effect that is used to atomize the fuel requires a pressure drop within the throat of the carbu retor The venturi that creates this pressure drop is a partial obstruction of the path into the engine Until recently the advantag
22. inkage bellcranks and rods are well lubricated not damaged and work as intended See Figure 3 5 ONNECTIN BRAK REAR BRAKE ARM ASSEMBLY BELLCRAN MOWN FING Figure 3 5 3 8 3 6 To check for brake drag open the the relief valve on each hydro pump With the parking brake released both wheels should rotate with hand pressure See Figure 3 6 anaE E HYDRO PUMP HYDRO I RELIEF VALVE 3 9 Figure 3 6 NOTE Some hydraulic system drag will be 3 10 present but a dragging brake will be immedi ately apparent 3 11 If in doubt about the source of brake drag dis connect the brake link rod from the actuator arm on the brake assembly The actuator arm should return to center releasing the brakes See Figure 3 7 Figure 3 7 Check the condition of the belt tensioner and belt that drives the hydro pumps See Figure 3 8 Figure 3 8 Before making neutral control and tracking adjustments make sure the relief valves on both hydro pumps are fully closed To check neutral control safely lift and support the rear wheels of the Tank Start the engine and release the parking brake Do not move the lap bars from the neutral posi tion If either wheel rotates neutral control adjustment will be necessary Turn off the engine 3 12 If adjustment is necessary remove the cutting deck Inspect the return to neutral cylinders rods and bellcranks of the hydro control linkages 3 13 e The bellcr
23. ion the ECU has a limp home mode that will allow it to plug in a fixed value in place of the reading from the mal functioning sensor 11 12 The Throttle Position Sensor tells the ECU what the position of the throttle plate is It is essen tially a potentiometer See Figure 11 12 Figure 11 12 If a TPS fails it will result in rough or erratic engine performance If a dead spot develops in the potentiometer the engine will run badly whenever the throttle is in a position that corre sponds with the dead range of the TPS 28 11 13 11 14 The TPS can be checked with an Ohm meter looking for jumps as the throttle is swept through its full range of travel lf the TPS mounting is disturbed for any reason there is a Kohler specified initialization proce dure that must be performed The engine temperature has a bearing on the fuel air mixture and ignition timing The ECU takes the engine s temperature with a ther mometer in the engine oil When the engine is cold the oil temperature is the same as the ambient temperature Being an air cooled engine as the engine warms up the oil temperature reflects a balance between engine load and ambient temperature when operating normally This is sufficient for the pur poses of the ECU A bad temperature sender may result in rich fuel air mixture accompanied by an erratic idle and somewhat reduced WOT power At 68deg f 20deg c the
24. oming from the outboard port on the hydro pump Use the 18 test kit line to connect the pressure gauge end of the hydraulic test kit to the line coming from the hydro pump See Figure 4 12 4 13 4 14 Figure 4 12 Tighten all the fittings Insure that no unsafe conditions will result from starting the engine and operating the drive sys tem CAUTION The technician will be exposed to moving parts during this procedure They should not reach past or around any moving parts during this test nor should they place themselves in any position where a loss of foot ing or balance might bring them into contact with rotating components Loose hair or garments should be secured to avoid the possibility of entanglement with rotating components 4 15 4 16 4 17 4 18 4 19 4 20 4 21 4 22 N E i lt w SEN 4 emm A gn a N b A e es wo it M48 Tank Remove the stop bolt that sets the end of the travel of the lap bar that controls the hydro pump to be tested See Figure 4 15 C AN A d VN TOP 10 N a i we e we Figure 4 15 Confirm that the valve on the test kit is fully open Start the engine and purge the hydraulic sys tem as follows Cycle the lap bar from full forward to full reverse 5 times at 10 second intervals Close the relief valve on the hydro pump and repeat the cycling process to purge any remain ing air from the system
25. or this A application i Return to tanks High pressure from fuel pump Figure 10 8 NOTE There are two potential failure modes for pressure regulators They may reduce the pres sure too far or they may not reduce the pressure far enough The second mode is more common NOTE If too much pressure is delivered to the injectors the engine will run extremely rich The problem will be very pronounced at idle but will clear up to some extent under high load open throttle conditions NOTE When an engine has run dramatically rich correct the core problem and change the oil before continued operation Oil dilution that may result from the rich condition may cause hydro lock and or catastrophic engine failure NOTE Check fuel pressure by connecting a fuel pressure gauge of adequate range eg NAPA Balkamp part number BK 700 1089 to the shrader valve on the fuel rail This will check regulated fuel pressure If fuel pressure at the shrader valve is below 36 PSI isolate the fuel pump and check output pressure and volume M48 Tank 10 9 The fuel filter is easily accessible See Figure 10 9 9t Fuel filter Figured 10 9 NOTE Use only identical factory replacement fuel filters Filters that are not capable of func tioning at 3 bar may rupture leak or disinte grate internally NOTE Prime the fuel filter with a few ounces of fuel when installing it The initial pressure surge into a dry
26. oved If the unit has been run recently allow it to cool before doing loosening any hydraulic fittings WARNING Hot hydraulic fluid can cause seri ous burns WARNING Release of pressurized hydraulic fluid can cause serious or fatal injury Open the relief valve on the hydro pump This will relieve any residual hydraulic pressure See Figure 6 7 Figure 6 7 Confirm that the hydraulic pressure has been relieved by rotating the brake drum hub assem bly If the it will not rotate confirm that the brake is released and that the brake linkage is not bound M48 Tank 6 9 Ifthe brake assembly is to be transferred to the 6 13 Disconnect the high pressure lines from the the new hydro motor remove the cotter pin from the hydro motor one at a time using a 7 8 wrench castle nut that holds the hub to the axle A 1 wrench may be required to hold the fittings on the hydro motor Plug the lines 10 L t th tle nut f 6 10 Loosen but do not remove the castle nut from See Figure 6 13 the axle using a 11 2 socket NOTE It may be necessary to set the parking WT VONNE brake while loosening the nut Release the parking brake afterward NOTE The studs are pressed into the brake drum The brake drum effectively is the drive hub The drive hub mounts on an narrow taper 6 11 Remove the hairpin clip that secures the brake link to the brake arm Pivot the arm out of the way See Figure 6 13 HIGH eg gt
27. p the fitting on the pump See Figure 5 14 Figure 5 23 M48 Tank 5 24 Remove the handle from the relief valve using a 5 29 Position the pulley over the opening in the hydro 7 16 wrench and a 3 16 allen wrench pump support plate that the pump input shaft will 5 25 Remove the nuts from the carriage bolts that pass through hold the hydro pump to the hydro pump mount 5 30 Position the pump so that the two bolts that ing plate See Figure 5 25 secure it in position line up with the two mount ing ears on the pump and the input shaft slips into the pulley as the pump is raised up to the hydro pump support plate See Figure 5 30 MOUNTING NUT RELIEF VALVE HANDLE REMOVED MOUNTING BOLT a whe 3 KEY KE ER an Se FITTINGS REMOVED mmm AND PLUGGED i um re on Figure 5 25 Ss YEW PUMP 5 26 Carefully lower and remove the hydro pump If it l is to be returned to Cub Cadet remove the yel Figure 5 30 low plugs and allow it to drain completely before packing and shipping it 5 31 Start both nuts that hold the pump onto their car 5 27 Inspect all of the fittings and O rings prior to riage bolts installation in the replacement pump 5 32 As the pump is tightened into position rotate the See Figure 5 27 pulley to align the keyways allowing the pulley to seat on the input shaft DEFORMED O RING GOOD O RING 5 33 Install the fittings and lines working quickly to minimize fluid loss
28. pick up Fuel return line Figure 10 3 10 4 The fuel lines from each tank Tee into a single line that feeds the fuel pump See Figure 10 4 Lef SEH S k Ba Sy Rom left tank Gg vs R d 7 m S amp S Fronrrig gy tank re Se or From pump Gs to filter Se Ri AAA AAA AA Figure 10 4 M48 Tank 10 5 10 6 The return lines each lead back to the tank from a tee fitting just beneath the tee fitting for the fuel feed lines The return fuel comes from the fuel pressure regulator NOTE If one branch of the return line becomes crushed kinked or blocked a disproportionate amount of fuel will return the the opposite tank If one fuel tank consistently empties before the other check the return lines If this situation should occur with full tanks an over flow will result The fuel feed line leads from the tanks and tee down to a high pressure fuel pump located beneath the ECM See Figure 10 6 Electronic Control Module Fuel pump Figure 10 6 CAUTION Before disconnecting any fuel line Allow the engine to cool and be sure the area is clear of any potential fire hazards and has ade quate ventilation Have a catch pan handy to contain any spillage Relieve pressure from the any fuel lines between the fuel pump and the fuel rail NOTE The fuel pump uses the fuel as a coolant If the engine runs out of fuel turn the key off immediately
29. problems There is only one wire on the oxygen sensor used in this application It does not have a heat ing element in it nor does it have a ground wire Some automotive applications have both of these features Because it does not have a ground wire it grounds through the body of the sensor and back through the engine exhaust system Oxygen sensors are susceptible to contamina tion from leaded fuel some RTV silicone seal ants some cleaning solvents Look for the words 02 Sensor safe on any of these products to be introduced up stream of the oxygen sen sor Oxygen sensors can be easily tested using a good quality high impedance DVOM or an oscil loscope Engine turned off hot sensor normal operating temperature should have a resistance from the disconnected wire to the housing or 2 0KQ Cold sensor should have a resistance of 1 0MQ Engine running above idle speed voltage mea sured from the disconnected wire remember do not disconnect or connect an wires while the engine is running should fluctuate between 0 1 volt and 1 0 volt This roughly approximates a sine wave on on oscilloscope A blip of the throttle should produce a momentary increase in voltage as the engine leans out slightly then re established correct mixture A steadily declining voltage that recovers from a throttle blip without fluctuating may indicate an improperly positioned TPS This is a simplified introduction to the EFI s
30. rements of adjust 8 5 Heavier hardware connects the deck to the ment See Figure 8 3 hangers See Figure 8 5 Figure 8 3 Figure 8 5 8 4 The larger heavier decks have a foot assist 8 6 Heavier front pivot bar and wider front track pedal to help raise and lower the deck See Figure 8 6 See Figure 8 4 S FELTA d Figure 8 4 17 M48 Tank 8 7 The track at the rear has also increased Extra 8 9 The parking brake lever has been moved up to a brackets have been added to the frame to step more convenient location the hydro motors out See Figure 8 7 Figure 8 9 Figure 8 7 8 10 A larger engine is required to power the larger 8 8 To enable the brake linkage to reach the reposi deck and heavier total weight of the mower A tioned hydro motor the rear brake arm assem 28 H P Generac Guardian engine is employed blies have been doubled up on each side see Figure 8 10 Instead of a single rear brake arm assembly per side two are used in tandem See Figure 8 8 auek 8 10 Figure 8 8 18 9 2 OTHER TANK FEATURES Honda Power is offered on the M48 HN and M54 HN The M48 HN has a 20 H P Honda V twin engine The M54 HN has a 24 H P Honda V twin See Figure 9 1 Figure 9 1 ROPS is offered on the M60 KW Kawasaki and M60 KH Kohler This is not a bolt on option It is integrated into the frame The option is prima rily aimed at government bid specifications See Figure 9 2 Figure 9
31. rk at low speed but cause intermittent ignition and injector action at higher speeds This will result in staccato misses and backfires 11 15 The exhaust gas oxygen O2 sensor contains a palladium insert When oxygen passes by palla dium an electrical current is generated Depending on the amount of oxygen flowing by the sensor it will generate between 0 10 and 1 00 volts see Figure 11 15 d e Figure 11 15 By measuring the amount of oxygen in the exhaust gas the ECU knows how much air is passing through the engine un burned It can make adjustments to the injector pulse length to adjust the mixture until the ideal fuel air propor tions are reached This ratio is known as sto chiometric ratio and is theoretically 14 7 parts air to 1 part fuel 14 7 1 Adjustments the ECU makes to the fuel air mix ture are the result of what is called closed loop operation The ECU is getting feedback on its performance from the oxygen sensor and mak ing adjustments based on that feedback Oxygen sensors do not work below about 700 deg F 375 deg C Because of this the engine will not go into closed loop operation until it is warmed up Because of inconsistent gas flow at idle speed most engines fall out of closed loop operation at idle speed 29 11 16 11 17 M48 Tank Reaching a conclusion from the previous two bullet points a bad oxygen sensor will not cause idle problems or cold running
32. ross member that it rests against in the released posi tion should be roughly 1 3 4 See Figure 7 20 Figure 7 20 M48 Tank 7 21 7 22 7 23 1 24 7 25 7 26 7 27 7 28 Release the parking brake The brake bracket should draw up against the frame cross member If this reaction is not con sistent tighten the shoulder nut slightly There should be roughly 1 1 2 between the head of the shoulder nut and the brake bracket when the brakes are applied Tighten the jam nut If brake application is uneven from left to right adjust the length of the short connector rods between the brake bracket and the brake bear ing hub If brake release action is inconsistent check for bent or misaligned rods and links Install the rear wheels tightening the lug nuts to 50 70 ft lbs Lower the TANK to the ground Install the floor panel Test run the TANK in a safe area before return ing it to service Check the function of the park ing brakes NOTE A dragging parking brake will cause tracking issue and drive noise on the effected side 8 M72 TANK The M72 is based on the same frame design as the smaller members of the TANK series Some changes have been made to accommodate the larger deck 8 1 Heavier brackets to suspend the deck See Figure 8 1 8 2 Heavier duty deck belt tension release mecha nism See Figure 8 2 Figure 8 2 16 M48 Tank 8 3 The deck lift goes has finer inc
33. ssure at the injectors is held con stant by the fuel pressure regulator The amount of fuel delivered to the cylinders is controlled by the length of time that the individual fuel injectors are triggered The length of time the injectors are triggered varies from 1 5 to 8 0 milliseconds Both injectors are triggered simultaneously Each triggering causes the injector to spray half the amount of fuel required by the corresponding cylinder on the next cycle The injectors are hot as long as the key switch is on The injection is triggered by the comple tion of a ground path within the ECU The injectors make an audible click each time they are triggered If this click cannot be heard or felt there may be a problem with the injector itself or there may be a problem in the wiring harness Figure 11 7 11 8 Ifa fuel injector is suspect the circuit may be tested with a commonly available noid light or the injector may be triggered using an electronic fuel injection pulse timer eg Thexton model number 139 in conjunction with a fuel pressure gauge With the key switch off triggering the injector should result in a measured drop in fuel pressure 27 M48 Tank 11 9 The ignition coils are also controlled by the ECU Each cylinder has its own coil See Figure 11 9 Wei 11 10 The plastic cased ECU is mounted to the frame above the fuel pump See Figure 11 10 Figure 11 10 11 11 Th
34. t for some loss of performance Within the two year Cub Cadet Commercial war ranty period replace the pump if it does not per form as specified and all other factors have been eliminated If a hydro pump requires repair refer to Hydro Gear publication BLN 51337 for complete ser vice instructions If the hydro pump and all other factors are O K replace the hydro motor NOTE The hydro motor is not serviceable Replace it as a unit if it fails REPLACING THE HYDRO PUMP If the cutting deck is currently on the unit remove it Safely lift and support the rear of the tank Remove the rear wheels using a 3 4 socket Tilt the seat up and disconnect the negative bat tery cable Remove the screen that covers the opening over the cooling fans on the hydro pump to be removed using a 3 8 wrench See Figure 5 5 REMOVE DEBRIS SCREEN Figure 5 5 5 6 Remove the nut washer and cooling fan from the hydro pump to be replaced using a 9 16 wrench See Figure 5 6 KE d e SS ZS a ei 8 E p eN yf Y Figure 5 6 5 7 Use a 3 8 breaker bar to move the belt ten sioner pulley arm slipping the belt off of the pul ley See Figure 5 7 LAA 28 MH i Ki ng Wy TENSIONER t af ARM iim EN A aai G e 4 a S N B A on lt lt ep 1 Figure 5 7 5 8 Unhook the spring that maintains tension on the arm This will provide more freedom of move ment 5 9 Slip the belt o
35. ure has been relieved by rotating the brake drum hub assem 5 21 a Remove the two O ring to JIC adaptors from the bly If the it will not rotate confirm that the brake back of the hydro pump Replace them with the is released and that the brake linkage is not yellow shipping plugs from the replacement bound hydro pump 5 16 If there is any possibility of fluid contamination 0 22 Remove the 90 deg elbow fitting that the return drain and flush the system and replace the filter line was connected to using an 11 16 wrench before installing the new hydro pump and a 3 4 wrench Plug the port using a yellow shipping plug removed from the replacement 5 17 Position a catch pan beneath the hydro pump to ump be removed Have four 1 2 JIC plugs and two BR 1 2 JIC caps within reach 5 23 Remove the O ring to JIC adaptor that the feed l line was connected using a 13 16 wrench Plug 5 18 Disconnect the feed line that runs from from the the port using a yellow shipping plug removed front of the hydro pump to the filter manifold from the replacement pump See Figure using a 7 8 wrench on the nut and a 13 16 5 23 wrench to hold the fitting on the hydro pump Plug the line cap the fitting on the pump 5 19 Disconnect the return line that runs from from the outboard side of the hydro pump to the res ervoir using a 7 8 wrench on the nut and an 11 16 wrench to hold the fitting on the hydro pump Plug the line ca
36. ver the drive pulley of the hydro pump to be removed M48 Tank 5 10 Use a small two jaw puller to remove the pulley from the tapered and keyed input shaft of the hydro pump See Ge 5 10 a bai ie s y ae i PULLER l HIT T 3 de EI Rb Ni 5 11 Disconnect the rod end on the back of the hydro control rod from the control arm on the hydro pump using a 9 16 wrench and a 1 2 wrench see Figure 5 11 Figure 5 10 ROD END LOCK WASHER CONTROL ARM Figure 5 11 NOTE There is a lock washer positioned between the rod end and the control arm 9 12 Thoroughly clean the area surrounding any hydraulic fittings to be loosened or removed 5 13 If the unit has been run recently allow it to cool before doing loosening any hydraulic fittings WARNING Hot hydraulic fluid can cause seri ous burns WARNING Release of pressurized hydraulic fluid can cause serious of fatal injury M48 Tank 5 14 Open the relief valve on the hydro pump that is 5 20 Disconnect the two lines that connect the hydro to be tested This will relieve any residual motor to the back of the hydro pump using a pair hydraulic pressure See Figure 5 14 of 7 8 wrenches Plug the lines See Figure 5 20 DA RETURN LINE d FEED LINE a vi S YU e We He HYDR n VW PRESSURE LINES ees PUMP gen PUMP _MOTOR A AND W wr FOR A K Figure 5 14 Figure 5 20 5 15 Confirm that the hydraulic press
37. ys tem used on the Kohler engine found on the TANK Complete diagnostic and service instruc tions can be found in the Kohler CH26 manual section 5B
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