SERVICE BRAKES 5-1 GROUP 5 SERVICE SHAKES
Contents
1. 146 to 14 TIGHTENING REFERENCE Foot Pounds Inch Pounds Rear Wheel Brake Support to Axle 35 Front Wheel Brake Mounting Bolt 8 Wheel Cylinder Mounting 0 0002 eee 200 Master Cylinder Cover Bolt een 50 Pedal Bracket Nut usos 20 Pedal Shaft eet ENS exce n UNT 20 Transmission Shaft Flange Bolt Nut 95 35 T VE e eb tide es a re asses 50 GROUP 5 SERVICE BRAKES The service brakes used on the 1962 Chrysler and The brake assemblies Figs 3 and 4 are eom Imperial Models are known as the three platform prised of dust shields brake shoes return springs type Total Contact Brakes Figs 1 and 2 and wheel cylinders SERVICE BRAKES 9 3 UPPER CYLINDER ASSEMBLY ANCHOR ADJUSTING CAM SHOE LINING DUST SHIELD SHOE RETURN SHOE RETAINER SPRING SHOE RETURN SUPPORT SPRING ADJUSTING CAM SHOE RETAINER CONNECTING TUBE LOWER CYLINDER ASSEMBLY 59x 138 Fig 1 Toial Contact Brakes Front Assembled View ADIUSTING CAMS CYLINDER SHOE RETURN DUST SHIELD SPRINGS m SHOE RETAINERS SUPPORT ANCHORS SHOE AND a LINING 59x139 Fig 2 Total Contact Brakes Rear Assembled ved2. 3 Disconnect the brake tube at the master cyl inder 4 Disconnect the stop light switch leads 5 Remove the nuts that attach the master cylin der to the dash panel Slide the master cylinder straight out and away from dash panel B Cleaning and Inspection Clean the outside of the master cylinder thorough ly remove the cover and drain all brake fluid Refer to Figure 17 and disassemble the master cylinder for inspection If the master eylinder piston is badly scored or corroded replace it with a new one The piston cups and valve assembly should be replaced when recon ditioning the master cylinder Master cylinder walls that have very light scratches or show signs of corrosion can usually be cleaned up with crocus cloth Cylinders that have scratches or scoring may be honed providing the diameter of the cylinder bore is not increased by more than 002 inch should be discarded and a new master cylinder used Black stains on the cylinder wall are caused by the piston cups and will do no harm Use extreme care in cleaning the master cyl inder after reconditioning Remove all dust or grit PISTON cet Lem Sea Fig 19 Master Cylinder Disassembled View Power Brake by flushing the cylinder with alcohol wipe dry with a clean lintless cloth and clean the second time with alcohol Dry the master cylinder with air pressure then flush with clean heavy duty brake fluid Be sure the compensating port
3. 5 4 SERVICE BRAKES SCREW ROD SHOE W LINING 60x398 CYLINDER CYLINDER SUPPORT SHOE LINING RETAINER SPRING WD RETAINER 7 SPRING e v fup el ES 4 e TUBE 86 e RETAINER SPRING M RETAINER gt Fig 3 Total Contact Brakes Front Disassembled View Brake shoe support is obtained by locating the brake shoes on three raised platforms pressed into the dust shield Each brake shoe is located on three platforms of the dust shield and guided by the three companion contact loops on the brake shoe Fig 5 The four shoes in the front wheel brakes and the two forward shoes in the rear wheel brakes are self energized when the car is moving forward These shoes are adjusted in the same direction while the remaining rear shoes in the rear wheels are ad justed in the opposite direction as shown in Figure 6 CAUTION To prevent brake drum distortion great care should be taken when changing wheels so that the wheel is properly seated and wheel stud nuts are correctly torqued When tightening the stud nuts alternately tighten the nuts to V 30 ft Ibs of the specified torque Then tighten to the final torque of 60 foot pounds SERVICE PROCEDURES When servicing the hydraulic bike system there are three important rules to remember 1 Vital parts of the system must be kept CLEAN
4. Fig 11 Measuring the Platform Height Tool MT 19 5 8 SERVICE BRAKES SUPPORT PLATE 60 x 327 Fig 12 Measuring the Platform Height Tool DD 1168 4 Check the tension of the brake shoe return springs The spring tension can be checked by hook ing a scale at the toe of the shoe and pulling in the direction of piston movement The scale should read 45 to 55 foot pounds at the instant the toe of the brake shoe moves A dial indicator may be used to indicate the shoe movement 5 Install the guide rod and the retainers Fig 8 Be sure the positioning lip of the guide rod is positioned properly in the spring retainer 6 Install the drum wheel and tire assembly after backing off the adjusting cams Adjust the front wheel bearings as described in Front Sus pension Group 2 7 Adjust the brakes 62x356 Fig 13 Installing the Brake Shoe Return Spring B Installing the Rear Brake Shoes Before installing the rear brake shoes apply a light coat of stick lubriplate on the raised platforms of the dust shield and on the shoe anchor where it con tacts the support plate 1 Slide the brake shoes into position between the support plates Be sure the ends of the cylinder push rods engage the toe end of the shoes properly Fig 10 2 Insert the brake shoe return springs in the link of the support plate Fig 10 3 Use Tool C 3462 as shown in Figure 13 to attach the springs to the loop o
5. a Reline both fronts or rears or all four b Smooth tire tread b Match the tire treads fronts or rears c Restricted brake line or hose Clean the brake line or replace the brake hose d Rough or scored brake drum d Reface or replace the brake drum Brakes Chatter a Saturated brake lining a Replace both fronts or rears or all four or Squeal b Loose support plate b Tighten the support plate c Rough or scored brake drum e Reface or replace the drum d Bent support plate d Replace the support plate e Bent brake shoes e Replace the brake shoes Machining grooves in contact surface of brake drum f Reface or replace the brake drum 5 16 Condition 1 Hard Pedal or Lack of Assist 2 Brake Pedal Slow to Return or Fail to Release SERVICE BRAKES SERVICE DIAGNOSIS VACUUM BRAKE BOOSTER Possible Cause a Stalled engine with loss of b m e d e f g a b e vaeuum Restricted or collapsed vacuum hose Leaking vacuum hose or fittings Faulty eheck valve Faulty brake booster assembly Master cylinder piston binding in the bore Hydraulie push rod out of adjustment Clogged air cleaner Ineorrect master cylinder push rod adjustment Weak or broken brake booster return spring d Binding brake pedal linkage Correction a b c d e f b d Start and adjust th
6. always apply pedal prior to adjusting the brakes This causes the brake shoes to center themselves to assist in the adjust ment A Front Brake Adjustment 1 Perform the following operations on one cam at a time on both front wheels Turn the adjusting cam in the direction of wheel forward rotation until the shoe lining is solidly against the drum as shown in Figure 6 and the wheel is locked 2 Turn the adjusting cam slowly in the oppo site direction until no drag is felt Repeat the oper ation on the other cam GASKET BODY OUTLET PORT INLET PORT PISTON WASHER 57x145B Fig 18 Master Cylinder Cross Section View Manual Brake 5 12 SERVICE BRAKES B Rear Brake Adjustment The rear wheel forward brake shoe adjusting cam is rotated in the direction of forward wheel rotation to bring the shoe lining nearer to the drum The rear brake shoe adjusting cam is rotated in the direction of wheel reverse rotation as shown in Fig ure 6 Repeat the adjustment procedure on rear wh l as outlined in the Front Brake Adjustment P SERVICING THE MASTER CYLINDER Figs 18 and 19 NOTE The master cylinder without power brakes has a fluted dust boot and retainer This retainer acts as a master cylinder piston stop The pedal return spring and pedal stop have been eliminated A Removal 1 Remove the master cylinder push rod clevis pin 2 Disconnect the push rod
7. pattern to determine if the shoes are true and shoe tables square with the web The lining should show con tact across the entire width extending from heel to toe Shoes showing contact on only one side should be examined and the cause determined Shoes Should be checked for squareness If the web is bent discard the shoe Shoes having sufficient lining but lack of contact at toe and heel should be inspected for proper grind The shoe should be inspected for lining overhang burrs at the anchor and loops In spect the raised platforms on the brake shield for height and flatness Nicks and burrs should be re moved CYCLEBOND BRAKE LINING Pre cemented MoPar cyclebond brake lining can be successfully bonded to either new or used shoes providing certain proven steps are followed See in structions and model applications contained in the MoPar replacement packages GRINDING RECOMMENDATIONS Brake Shoe Lining New lining if not pre ground should be inspected and ground 010 to 024 inch under the drum diameter on a machine having a cylindrical grinding wheel B Drum Refacing Measure the drum runout with an accurate gauge Drum runout should not exceed 004 inch out of round If the drum runout is in excess of 004 inch the drum should be refaced Remove only as much material as is necessary to clean up the drum NOTE Do not remove more than 030 inch of metal during the refacing operation If the drum has hard spots i
8. AND SPECIFICATIONS ALL MODELS ot eir Hydraulic Total Contact Internal Expanding Drum Diameter Front Rear SC 1 Newport celere Ro RR e ns 122 Wheelbase 11 8 2 2800 ose eet et re tn Ped hs 122 Wheelbase 12 SC 1 Town and 122 Wheelbase 12 SC 3 New Yorker incl Town amp Country 126 Wheelbase 12 SY 1 Imperial el eens Hee ae 129 Wheelbase 12 aal 9 2 SERVICE BRAKES DATA AND SPECIFICATIONS CONT D Lining Types ee bids nite Lia bo pew Las kir aure wil Paetus E Ted Molded Asbestos Attached to Shoes 2 222 Cyelebond Width All Models en Front 214 Rear 214 Thickness as kat iret RM nne eme UERE ATO Brake Shoe Return Spring Tension Pounds Front ose ie ae Pe GE 45 to 55 Pounds Rear n 45 to 55 Per Cent of Braking Torque Rear 40 Diameter of Wheel Cylinder 114 Diameter of Master Cylinder 1 Piston Cylinder Clearance 2 008 to 0065 Brake Pedal Free Play Power
9. SERVICE BRAKES 5 1 GROUP 5 SERVICE BRAKES CONTENTS Page Brake Adjustment cone 0 eos Stee NER ERROR Aloe aree stet deque Ro gen a 11 Brake Hose and Fines ceto Ene x wr EES ee P s 12 Brake Grinding Recommendations meme eee 7 Brake Lining Cyclebottd x as osea Gores es doo t tage een e aei eed peres bx s 7 Brake Shoe Inspection heme renes 7 Brake Shoe Installation I RH hm hene 7 Brake System EE 11 Brake Shoe seid ette ins ate 5 Data and Speeifieations eee hme emnt 2 Fluid Contamination 2 4 2 1 11 Front and Rear Support Plates and Wheel Cylinders 222 8 Front and Rear Support Plates and Wheel Cylinders Installation sees 10 Master Cylinder eh eh hh epe rhe hh eres 12 Service Diagm als d caue UP Race uuo OR Pale ke pee Pet e RE Ege e err da 15 VACUUM BRAKE BOOSTER Brake Booster Installation Rh he hehe 18 Brake Booster Removal NINE ELCHE NE 13 DATA
10. b Restrieted brake line or hose b Clean the lines or replace the hose e Brake shoes binding on support Sand and lubricate the brake shoe plat plate forms d Weak or improper brake shoe d Replace the brake shoe return springs return e Swollen wheel cylinder cups e Replace the wheel cylinder cups f Bent or out of round brake drum f Reface or replace the brake drum Hard Brake Pedal a Lining hard or glazed a Replace the brake shoes b Frozen brake pedal linkage b Free up and lubrieate the brake pedal linkage c Restricted brake line or hose c Clean out the brake line or replace the brake hose d Inoperative power unit d Test operation of the power unit correct as required Soft or Spongy Brake a Air in hydraulic system a Bleed the hydraulie system Pedal b Brakes improperly adjusted b Adjust the brakes c Flexible hose deteriorated by c Replace the brake hose and bleed the grease or oil hydraulie system d Bent brake shoes d Replace the brake shoes Brakes Pull a Lining saturated with grease or a Reline both fronts or rears or all four brake fluid b Out of round brake drum b Reface or replace the brake drum e Frozen wheel cylinder c Recondition or replace the wheel cylinder d Restricted brake line or hose d Clean out the brake line or replace hose e Loose lower control arm strut Tighten the lower control arm strut One Wheel Locks a Saturated lining
11. cylinder dip them in Super Brake Fluid Refer to Figures 16 and 17 then assemble the brake cylinders If the boots are deteriorated or do not fit tightly on the brake shoe push rod or on the wheel cylinder casting new boots should be in stalled INSTALLING THE FRONT AND REAR SUPPORT PLATES AND WHEEL CYLINDERS A Installation Front Support Plates and Wheel Cylinders 1 Install the brake cylinders on the support plates position the support plates on the dust shield Be sure the dust washers are in place Install the wheel cylinder attaching bolts and tighten 15 to 20 foot pounds torque 2 Slide the brake assemblies over the steering knuckles Install the bolts nuts and tighten to 55 foot pounds torque Measure the dust shield for the platform height 3 Lubricate the adjusting cams of the support plate assembly lightly with stick lubriplate then slide brake shoes into position between the support plates 4 Install the brake shoe return springs through the link of the support plate and use Tool C 3462 to attach the spring to the brake shoe as shown in Figure 13 5 Install the brake shoe guide rod spring and retainers 6 Install the wheel cylinder connecting tube being careful not to bend or distort the tube T Turn the brake adjusting cams to the fully released position Attach the brake hose to the frame bracket Connect the brake tube 8 Install the drum and wheel assembly Adjust the front whe
12. e engine for proper idle Inspect and replace the faulty hose Inspect the hoses and replace the faulty hose Tighten and seal all fittings Replace the check valve Replace the brake booster Recondition the master cylinder Remove the brake booster and deliver to the servicing dealer for adjustment Clean with solvent and dry with com pressed air Remove the brake booster and master cylinder and deliver to the servicing dealer for adjustment Remove the brake booster and deliver to the servicing dealer Free up the linkage and lubricate
13. el bearing as described in Front Sus pension Group 2 9 Bleed and adjust the brakes B Installation Rear Support Plates and Wheel Cylinders 1 Place the wh el cylinder on the support plate and install the attaching bolts Tighten the bolts 5 to 20 foot pounds torque 2 Install new seal in the dust shield if needed and install the seal protector Tool C 745 into the seal Install the dust shield and the seal over the axle shaft and down against the flange 8 Slide the support plate assembly over the axle shaft y 4 Install the lockwashers and nuts Tighten the nuts to 35 foot pounds torque Measure the dust shield platform height 8 Slide the brake shoes into position between the support plates after lubricating the cam finger and anchor reaction area with stick lubriplate 6 Install the brake shoe return springs through the link of the support plate and use Tool C 3462 tp attach the spring to the eli of the brake shoe ax 7 Install the brake sho fgpide rod and retainers 2 Be sure the positioning lip ef the guide rod is tioned into the slot of the retainers i 8 Turn the brake adjusting cams to the fully released position and attach the brake line to the wheel cylinder Remove the Tool 745 9 Insert the key on the slot in the axle shaft chalk the axle shaft and install the drum Install the wheel and tire Bleed and adjust the brakes as described i
14. etween the wheel cylinders NOTE Do not distort the tube 8 Remove each wheel cylinder mounting bolt after removing the sealer Remove the support plate assembly from the dust shield as shown in Figure 15 9 Remove the wheel cylinders If it is necessary to service the wheel cylinders refer to Paragraph Servicing the Wheel Cylinders B Removal Rear Support Plates and Wheel Cylinders 1 Remove the rear brake shoes 2 Disconnect the brake tube at the wheel cylin der Remove the nuts and lockwashers that attach the support plates and wheel cylinders to the dust shield and axle housing flange CYLINDER AND C BOOTS PLATE DUST SHIELD 60 x 329 Fig 15 Removing the Rear Support Plate SERVICE BRAKES 5 9 3 Slide the support plates out and away from the axle as shown in Figure 15 When removing the dust shield it is advisable to install the seal pro tector Tool C 745 then slide the dust shield and seal off axle 4 Remove the bolts that attach the wheel cylin der to the support plate Lift the wheel cylinder away from the plate Inspect and clean the support plate If reconditioning the wheel cylinders refer to Paragraph Wheel Cylinders C Cleaning and Inspection Support Plates Clean the support plates in a suitable solvent blow dry with compressed air and inspect as follows Check the freeness of the adjusting cams and re turn spring links The adjusting cams
15. f the shoe table 4 Install the guide rod retainers Fig 8 Be sure the positioning lip of the guide rod slides into the slot of the spring retainer 5 Measure the tension of the brake shoe return springs The spring tension can be measured by hooking a scale at the toe of the shoe and pulling in the direction of piston movement The scale should read 45 to 50 foot pounds at the instant the toe of the shoe moves A dial indicator may be used to in dicate the shoe movement 6 Install the drum wheel and tire assembly after backing off the adjusting cams 7 Adjust the brakes REMOVING THE FRONT AND REAR SUPPORT PLATES AND WHEEL CYLINDERS A Removal Front Support Plates and Wheel Cylinder 1 Remove the wheel tire and brake drum as sembly SUPPORT gt 2 CYLINDER AND DUST SHIELD Fig 14 Removing the Front Support Plate 2 Remove the four retaining nuts attaching the support plates and dust shield to the steering knuckle 3 Disconnect the flexible brake hose from the frame bracket 4 Remove the four bolts that attach the brake assembly to the steering knuckle Note the location of the bolts and the size Three different lengths are used 5 Remove the brake assembly as shown in Figure 14 CAUTION Do not allow the dust shield to strike the bearing surface of the knuckle as damage may result 6 Remove the brake shoes 7 Remove the connecting tube b
16. free from dirt grease and oil SHIELD SERVICE BRAKES 5 5 SPRING SHOE W LINING ROD LN CYLINDER E i RETAINER RODA N MEE A SPRING X RETAINER AL UNING 77 60x807 Fig 4 Total Contact Brakes Rear Disassembled View 2 The system must be free from entrapped air and all connections must be tight upon completion of any service job 3 Use only factory recommended type high boil ing point MoPar Super Brake Fluid CYUNCER SPRING LOOP PLATFORMS A Fig 5 Haised Platform and Shoe Contact Loops CONTACT LOOPS BOxNS BRAKE SHOES REMOVAL Figs 3 and 4 A Removing the Front Brake Shoes 1 Block the brake pedal to prevent any down ward movement of the pedal 2 Remove the front wheel and drum as an as sembly after backing off the adjusting cams 3 Use Tool C 3462 to remove the shoe return springs as shown in Figure 7 The end of the tool should be inserted between the spring and the brake shoe web to remove the shoe return spring LEFT FRONT RIGHT FRONT LEFT REAR RIGHT REAR QUO 55x708 Fig 6 Brake Adjusting Diagram 5 26 SERVICE BRAKES Fig 7 Removing the Brake Shoe Return Spring CAUTION Do not use brake spring pliers or damage to the lin ing will result 4 Turn the brake shoe guide retainer 14 turn then the retainer guide spring and rod as shown in Figure 8 NOTE The lip on the end
17. in the master cylinder is open C Assembly Before assembling the piston cups and valve assem bly should be dipped in new brake fluid Refer to Figure 18 for master cylinder assembled BRAKE HOSE AND LINES Inspection of brake hose should be included in all brake service operations The hoses should be checked for 1 Correct length severe surfaces cracks pul ling scuffing or worn spots 2 Faulty installation causing twisted hose and wheel tire or chassis interference 8 Always use the factory recommended hose to insure quality length and long service life Care should be taken to make sure the seating surfaces are clean and free from nicks and burrs Copper washers are to be used and the tube nuts and con nections properly made and tightened 4 Double tubing should always be used to in sure long life and corrosion resistance Flares and acute angles should always be accomplished with the properl tools to guard against leaks and restrictions from reduced tube cross section SERVICE BRAKES 5 13 VACUUM BRAKE BOOSTER The tandem diaphragm type brake booster is a self contained vacuum hydraulie power braking unit It is of the vacuum suspended type which utilizes en gine intake manifold vacuum and atmospheric pres sure for its power This type of unit does not re quire a vacuum reservoir The basic elments of the vacuum unit are as follows a The vacuum power chamber consists of a front and
18. k and install the res ervoir cover Adjust ail the brake shoes as outlined in the Brake Shoe Adjustment Procedures TEST FOR FLUID CONTAMINATION In order to determine if contamination exists in the brake fluid which may be indicated by swollen de teriorated rubber cups the following simple tests can be made 1 Place a small amount of drained brake fluid in small clean clear glass bottle Separation of the fluid into two distinct layers may indicate mineral oil contamination 2 Add 1 part water to two parts of the drained SERVICE BRAKES 5 11 brake fluid and shake If the contents become milky mineral oil may be present If the contents remain clear it is not contaminated with mineral oil Be safe and discard old brake fluid that has been bled from the system NOTE Fluid drained from the bleeding operation may contain dirt particles or other contamination and should not be reused ADJUSTING THE BRAKES cams nave 145 inch hex adjusting head and operate against the toe end of the shoe web and ex tend through the brake dust shield The four shoes in the front wheel brakes and the two forward shoes in the rear wheei brakes are self energized when the vehicle is moving forward these shoes are tightened in the forward direction while the rear shoes in the rear wheels are tightened in the reverse dirction as shown in Figure 6 NOTE Whenever the brakes have been relined or new shoes have been installed
19. n Paragraph Bleeding the Brake Sys tem BLEEDING THE BRAKE SYSTEM NOTE During the following operations use MoPar Super Brake Fluid 1 Clean all the dirt from around the master cylinder reservoir cover and from the bottom of the power brake cylinder if so equipped 2 Remove the reservoir cover and install Brake Bleeder Tank Tool C 3496 or its equivalent with adapter Tool 349 3 Raise the car wheels from the ground and baek off the brake shoe adjusting cams to the fuily release position This allows the brake shoe to force the wheel cylinder pistons and cups as far back into the wheel cylinder as possible trapping all the air near the bleeder screw hole 4 Clean all dirt from the wheel cylinder bleed valve and attach Bleeder Hose Tool C 650 to the valve Place the other end of the hose in a clean uncontaminated jar so the fluid can be reused Use only MoPar Heavy Duty Brake Fluid Part No 1879268 Bleed each wheel cylinder for a minimum of thirty seconds of continuous fluid flow in the fol lowing order Right rear left rear right front lower right front upper left front lower left front upper CAUTION Water and any type of mineral oil product such as gasoline engine oil etc will contaminate brake fluid It is extremely important that the container used to catch the brake fluid be clean free of moisture and must never at any time have contained mineral oil in any form 5 Remove the bleeder tan
20. of guide rod is used for positioning the guide rod into the slot of the spring retainer 8 Slide the shoes from between the support plates as shown in Figure 9 B Removing the Rear Brake Shoes 1 With the brake pedal blocked to prevent any BRAKE SHOE GUIDE SPRING RETAINERS 60X216 Nes Fig 8 Removing the Brake Shoe Guide Spring Rod and Retainer Da 160 217 Fig 9 Removing the Front Brake Shoe downward movement back off the adjusting cams The shoes and support plates may become bent if the cams are not backed off 2 Remove the rear wheel Use puller Tool C 845 to remove the rear wheel drum CAUTION Do not use a knock off type wheel puller 3 Use Tool C 8462 to remove the shoe return springs as shown in Figure 7 The end of the tool Should be inserted between the spring and the web of the brake shoe to remove the shoe return spring CAUTION Do not use brake spring pliers or damage to the lin ing will result 60X218 cci d Fig 10 Removing the Rear Brake Shoe 4 Turn the brake shoe guide retainer turn then remove the retainer and guide rod refer to Fig 8 NOTE The lip on the end of guide rod is used for positioning the guide rod into the slot of the spring retainer 5 Slide the shoes from between the support plates Fig 10 INSPECTING THE BRAKE SHOES Wipe or dry brush clean the metal portions of the brake shoes Examine the lining contact
21. r cylinder from the brake booster CAUTION Do not attempt to disassemble the brake booster as this unit will be serviced by the Manufacturer s Service Station BRAKE BOOSTER INSTALLATION 1 Install the master cylinder on the brake boost er 2 Insert the brake booster push rod through the brake support and install the four attaching washers and nuts 3 Install the push rod attaching bolt and nut through the push rod and brake pedal 4 Attach the vacuum hose to the check valve 5 Attach the brake line to the master cylinder 6 Fill the master cylinder and bleed the brakes 7 Inspect the adjustment of the stop light switch CHECK VALVE DIAPHRAGM hA FIF IIL Y 2 VALVE HOUSING VALVE HOUSING SEAL HIN CU 1 1 17 SES avid gt XD d ad ANE gt TL VALVE RETURN SPRING y ans CENTER PLATE Fig 20 Vacuum Brake Booster 62x423 SERVICE DIAGNOSIS SERVICE BRAKES SERVICE BRAKES 5 15 Condition Possible Cause Correction Brake Pedal oes to a Excessive shoe clearance a Adjust the brakes the Floor b Dry master cylinder b Fill the master cylinder e Worn brake lining c Adjust or replace the brake shoes d Broken brake line d Replace the broken brake line and bleed system e Scored master cylinder cup e Recondition the master cylinder Dragging Brakes a Insufficient shoe clearance a Adjust the brakes
22. rear shell a center plate front and rear diaphragm hydraulic push rod and a vacuum dia phragm return spring Fig 20 0 A mechanically actuated control valve in tegral with the vacuum power diaphragms controls the degree of power brake application or release in accordance with the foot pressure applied to the valve operating rod through the brake pedal link age The control valve is of a single poppet type valve with an atmospheric port and a vacuum port The vacuum port seat is a part of the valve body at tached to the diaphragm assembly The atmospheric port is a part of the valve plunger which moves with in the valve housing and vacuum power diaphragm assembly c hydraulie master cylinder which contains all of the elements of the standard brake master cylinder except for the special hydraulic push rod which is a part of the brake booster CAUTION Do not attempt to adjust the hydraulic push rod SERVICE PROCEDURES BRAKE BOOSTER REMOVAL 1 Disconnect the brake line from the master cylinder 2 Disconnect the vacuum line from the check valve 3 From under the dash remove the push rod nut and bolt from the brake booster and brake pedal 4 From under the dash remove the four brake booster attaching nuts and washers 5 Withdraw the brake booster and master cy linder assembly from the booster support bracket 6 Remove the four master cylinder attaching nuts and washers and remove the maste
23. should turn without binding 7 10 foot pounds Do not turn the adjusting cams unnecessarily A small amount of rotation will tell if cam torque is correct Inspect the condition of the adjusting cam dust shield washers If the washers are cracked or deteri orated new ones should be installed during assem bly If any visual distortion of the support plates is apparent new plates should be installed The sup port plates must be flat D Cleaning and Inspection Wheel Cylinders Wheel cylinders pistons that are badly scored or corroded should be replaced The old piston cups should be discarded when reconditioning the hy draulic system EXPANDER 357x357 Fig 16 Front Wheel Clyinder 5 10 SERVICE BRAKES soor AP PISTON ge EXPANDER FA E CUP x 4 SPRING EXPANDER PISTON 57x358 A Fig 17 Rear Wheel Cylinder Cylinder walls that have very light scratches or show signs of corrosion can usually be cleaned up with crocus cloth using a circular motion However cylinders that have scratches or scoring may be honed using Tool C 3080 providing the diameter of the cylinder bore is not increased by more than 002 inch Any cylinder bore increased by more than 002 inch should be discarded and a new cylinder in stalled Black stains on the cylinder walls are caused by the piston cups and do not cause any damage Before assembling the pistons and new cups in the wheel
24. t must be ground or replaced SERVICE BRAKES 9 7 Knowing the drum diameter the proper measure ment is then placed on the grinder and the lining ground to the required clearance of 010 to 024 inch under drum diameter The grinding of brake linings need only be done if the cyclebond process is done in the dealership or the drum is refaced INSTALLING THE BRAKE SHOES CAUTION Whenever the brake shoes are removed from the dust shield on a noise complaint the brake shield platforms should be measured for flatness and height Measure platform height as shown in Fig ures 11 and 12 with Tool MT 19 J or Tool DD 1168 with the shoes in place and a feeler gauge The plat forms should be in the same plane within 010 inch A Installing the Front Brake Shoes Before installing the front brake shoes apply a light coat of stick lubriplate on the raised platforms of the dust shield and on the shoe at the anchor reaction area end at the cam finger 1 Slide the brake shoes into position between the support plates Be sure the ends of the cylinder push rods engage the toe end of the shoes properly 2 Insert brake shoe return springs in the link of the support plate 3 Use tool C 3462 as shown in Figure 18 to attach the return springs to the loop of the brake shoe table NOTE Be sure that the end of the spring is hooked into the loop of the shoes properly to prevent the coil of the spring contacting the shoe 60 x 326
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