Pressure Probes - Snap-on
Contents
1. EAK0171L100A Sticking pressure relief valves Anti Drainback valve Internal Engine 500 psi EAKO171L10A Transmission Transaxle Valve train Compression Fuel system Oil system Exhaust restrictions Piston ring integrity Intake integrity Head gaskets failure Open gasket failure Camshaft timing failure Restricted filters Clutch and band Internal Solenoid pack Electronic failure Line pressure Worn seals 5000 psi EAK0171L20A Power Steering Pump and rack Variable assist Brakes ABS The following sections contain typical examples of some of these tests Connections e Set the gear selector in neutral for a standard transmission or park for an automatic transmission Set the parking brake If the vehicle has an automatic parking brake release disconnect the release mechanism for testing and reconnect when testing is complete e Read understand and follow Safety Information in the front of this manual Use this procedure to connect the pressure probe to the tester and vehicle for all tests in this section 1 Connect auxiliary extension lead to the TIMING AUX receptacle on the connection panel Connect pressure probe lead to the auxiliary extension lead PP 5 Pressure Probe Kit 3 Connect pressure probe to the pressure probe lead 4 Calibrate the pressure probe J For ad2. 1 To detect open valve failure on the cylinder pressure waveform first verify piston ring integrity J For additional information refer to Piston Ring Integrity Test 2 After piston ring integrity has been verified and the possibility of a head gasket failure has been eliminated perform Cylinder Compression Test with closed throttle Interpretation Open valve failure is indicated by a loss of pressure during the Compression Position and Vacuum Positions 1 and 2 of the cylinder pressure waveform PP 15 Pressure Probe Kit Camshaft Timing Failure J For waveform interpretation information refer to Waveform Guidelines on page PP 11 Timing failure can be detected on the cylinder pressure waveform Timing failure is indicated by either e A lower than normal pressure reading at the ready position of the cylinder waveform with higher than normal readings at Vacuum Positions 1 and 2 of the cylinder waveform or e A higher than normal pressure reading at the ready position of the cylinder waveform with lower than normal readings at Vacuum Positions 1 and 2 of the cylinder waveform To verify camshaft timing failure test non adjacent cylinders or opposite bank cylinders for similar results Engine Oil Pressure Test The oil pressure waveform shows internal oil pressure fluctuations over a specific period of time and conditions Figure 7 Normal Oil Pressure Testing Tips O At normal operating temperature the rise to
3. full stable oil pressure typically takes less than one second When oil pressure testing is performed on a cold engine it typically takes longer to register full stable oil pressure OA cold engine typically has higher than normal oil pressure until the engine reaches normal operating temperature O Oil pressure typically increases with higher engine RPM and decreases with lower engine RPM O Over an extended period of running time at constant RPM engine oil pressure normally drops Engine oil becomes thinner as the engine temperature increases and allows oil to flow more easily past the engine bearings Test 1 For standard testing Set Signal Channel 1 Aux 500 psi Channel 2 OFF Set Pattern Sweep 10 sec Set Scale 100 psi Set Trigger Auto PP 16 Pressure Probe Kit 2 Locate and remove engine oil pressure sending switch Do not touch hot engine components Wear gloves when handling hot engine components 3 Attach oil pressure test adaptor to oil pressure sending switch port on engine 4 Attach pressure probe to oil pressure test adaptor When installing the pressure probe into the appropriate adaptor use care to not overtighten the pressure probe 5 Start engine 6 Run vehicle engine to achieve normal operating temperature Internal Pressure Relief Valve Failure Sticking The oil pressure waveform rises quickly to point A Typically the oil pressure waveform then drops to p
4. point Piston quickly decreases in speed and stop at the end of the stroke Piston has stopped at TDC Exhaust valve has closed Intake valve is ready to open F Intake Position Intake valve has opened Piston has rapidly resumed movement Down stroke of the piston draws air into the cylinder through the open intake valve Piston reaches top speed at the halfway point Piston quickly decreases in speed and stop at the end of the stroke G Vacuum 2 Position Intake valve has closed Piston down stroke has drawn a slight non detectable vacuum in the cylinder A closed throttle registers a detectable vacuum Piston has stopped at BDC H Compression Position Both valves are closed Piston has rapidly resumed movement Cylinder contents are compressed on the piston up stroke Piston reaches top speed at the halfway point Piston quickly decreases in speed and stop at the end of the stroke Pressure Probe Kit Additional Cylinder Pressure Tests e Piston Ring Integrity Test e Intake Integrity Test e Exhaust Restriction e Intake Restriction e Head Gasket Failure e Open Valve Failure e Camshaft Timing Failure Piston Ring Integrity Test J For waveform interpretation information refer to Waveform Guidelines on page PP 11 1 Perform Cylinder Compression Test 2 Save results 3 Remove pressure probe from cylinder pressure test adaptor 4 Remove cylinder pressure test adaptor from engine 5 Squirt a s
5. specifications for compression data J For waveform interpretation information refer to Waveform Guidelines on page PP 11 PP 9 Pressure Probe Kit Disabling the Fuel System ACAUTION Relieve fuel system pressure before testing Refer to the vehicle manufacturer s procedure for disabling the fuel system Some common methods of disabling the fuel system follow Many newer fuel injected systems can be put into this mode by depressing the Clear Flood Mode accelerator fully to the floor and cranking the engine This keeps the fuel injectors from activating Most Ford vehicles are equipped with an inertia switch Lifting the plunger on the Inertia Switch top of the switch deactivates the fuel pump After tripping the switch crank the engine to burn any residual fuel in the fuel rail May be centrally located in the power distribution or maxi fuse panels remove Fuer Rump Relay this relay to disable the fuel pump Fuel Injector Fuse s Usually located in the fuse panel removing this fuse disables the fuel injectors Usually located in the fuse panel removing this fuse can disable the fuel injectors Sometimes it disables the fuel and ignition systems Be sure to check ECM PCM Power Fuse s for spark IMPORTANT Be aware these fuses may supply keep alive memory and removing them may erase learned memory from the PCM Disabling the Ignition System Refer to the vehicle manufacturer s p
6. N indicates a potentially hazardous situation which if not avoided may result in moderate or minor injury to operator or bystanders Safety messages in this manual contain three different type styles e Normal type states the hazard e Bold type states how to avoid the hazard e Italic type states the possible consequences of not avoiding the hazard An icon when present gives a graphical description of the potential hazard SAVE THESE INSTRUCTIONS A Risk of explosion e Exceeding the pressure limits of the pressure probes and or adaptors can cause the equipment to burst e The pressure probe lead used with pressure probes should not be exposed to temperatures exceeding 250 F Explosion can cause injury Risk of sudden vehicle movement AWARNING e Set the gear selector in neutral for a standard transmission or park for an automatic transmission Set the parking brake If the vehicle has an automatic parking brake release disconnect the release mechanism for testing and reconnect when testing is completed e Disable fuel and ignition systems before testing Check manufacturer s service manual for procedures A moving vehicle can cause injury PP 2 AWARNING ACAUTION ACAUTION ed IMPORTANT Pressure Probe Kit Risk of flying particles Wear safety goggles user and bystander e Do not exceed specified operating psi for any pressure probe e Be sure all connections are secure Flyin
7. Pressure Probes EAK0171L00A 100 psi EAK0171L10A 500 psi EAK0171L20A 5000 psi Table of Contents Safety INTOMMAOn ien 2S arto k Lae ised A ai nie War A a ie aa aa Shee sae a a Bath 1 Introduction ocs eseas oie ho Bee ae ea Bee ane ea Si Pea ee pe eA AP Be ani aia Gaede es 4 Functional Description ssoi sees wea pa eee RE ea ep oe Rema Po le 4 Connections enna airia wa Sand Red aod SHE BAL a ee LE Dee ek ak LARS NT Gok PEA Dae N 5 Hhest Preparations zresa Leese Bein Lea Waa ed Patna aah Pa ad Oey eS Oa a ROR Ay 6 Pressure Probe Tests rier o ogui deias Wek Ra Dae ae OR ROE be oe Red ob ea Sd elite 6 Before Testing 222 iig aiie eid oe echt ev a ne we descr se eee Pee eee 7 Cylinder Compression Test reis teekenaar eeaeee eee 8 Waveform Guidelines 000 eee eee 11 Additional Cylinder Pressure Tests 000 c cece eee eee eee 13 Engine Oil Pressure Test 0 cece etna 16 Transmission Pressure Test 0 00 eee eee eee 18 Safety Information IMPORTANT SAFETY INSTRUCTIONS Pressure probes are highly sophisticated test instruments intended for use by properly trained skilled professional automotive technicians Safety warnings and cautions in this manual are reminders to operator to exercise extreme care when using this test instrument There are many variations in procedures techniques tools and parts for servicing vehicles as well as in the skill of the individual doing the work Because
8. ditional information refer to Pressure Probe Calibration 5 Connect pressure probe to vehicle 6 Select Scope Special Patterns Pressure Probes 7 Setup Scope as necessary for testing J Pressure probe calibration is required when a different pressure probe is selected or if exit and return to the scope Calibrate pressure probes at any time by selecting Pressure Probe Calibration from Tools F4 Test Preparations Tests in this manual assume that Tester is on warmed up and calibrated Leads are connected to vehicle in standard configuration Vehicle identified using Vehicle ID Description Quick ID or Restore Data Vehicle parking brake is applied Gear selector is in Neutral if equipped with a manual transmission or Park if equipped with an automatic transmission Drive wheels are blocked Parking brake is set and If vehicle equipped with automatic parking brake release disable release mechanism All testing tips and safety requirements are observed Pressure Probe Tests Use any of the 0 100 0 500 and 0 5000 psi pressure probes on any vehicle system requiring pressure measurements PP 6 Pressure probes must be calibrated before each use to maintain accuracy JY For additional information refer to Pressure Probe Calibration in this manual Pressure Probe Kit Before Testing Perform pressure probe calibration before testing J Refer to Safety Informa
9. er pressure e To diagnose the point of restriction test adjacent cylinders and or opposite cylinder bank Figure 5 Exhaust Restriction Waveform Intake Restriction Performing a cylinder pressure test can detect an intake restriction J For waveform interpretation information refer to Waveform Guidelines on page PP 11 Interpretation e An unrestricted intake registers no significant vacuum ina throttle open mode during the intake position of the cylinder pressure waveform A restricted intake draws a detectable vacuum in a throttle open mode during the intake position of the cylinder pressure waveform To diagnose the point of restriction test adjacent cylinders and or opposite cylinder bank PP 14 Pressure Probe Kit Head Gasket Failure To detect head gasket failure on the cylinder pressure waveform first verify piston ring integrity J For additional information refer to Piston Ring Integrity Test J For waveform interpretation information refer to Waveform Guidelines on page PP 11 Interpretation e A failed head gasket is indicated by a loss of pressure during the Compression Position and Vacuum Positions 1 and 2 of the cylinder pressure waveform e To verify a failed head gasket indication test adjacent cylinders for similar results Lf ONE ee O Figure 6 Head Gasket Failure Open Valve Failure J For waveform interpretation information refer to Waveform Guidelines on page PP 11
10. g particles can cause eye injury Risk of entanglement Keep yourself clothing and test equipment clear of moving parts Entanglement in moving parts can cause injury Be sure that all of the equipment that is being used is approved for the use intended and can handle the pressure involved in the testing sequence Use only as described in this instruction manual Use only the manufacturers recommended attachments Risk of burns Do not expose the pressure probe lead used with pressure probes to temperatures exceeding 250 F Burns can cause injury Before each use of this accessory inspect the connector for bent or missing pins and inspect the cable for damage Also inspect both connectors for foreign objects or dirt and clean if necessary e When inserting the connectors align the keyed detents Do not use excessive force and do not rock the connectors back and forth while inserting When removing the connectors grasp the connector housing Do not pull the cable e Do not let the cable touch the exhaust manifold Flush pressure transducer hoses and adaptors with gasoline or parts cleaning solvent after use with methanol or methanol blended gasolines e Periodically check all parts of the pressure probe kit for signs of wear or damage and replace items when worn Never use equipment that is showing signs of wear or damage until it has been examined by a qualified Snap on service representative Pressure tran
11. ion transaxle it typically takes slightly longer to register full stable automatic transmission transaxle pressure OA cold automatic transmission transaxle typically has slightly higher than normal pressure until the automatic transmission transaxle reaches normal operating temperature Test 1 For standard testing Set Signal Aux Off 500 psi Set Pattern Sweep 5 sec Set Scale 250 psi Set Trigger Auto 2 Locate automatic transmission transaxle test ports per manufacturer specifications 3 Attach automatic transmission transaxle pressure test adaptor to the desired automatic transmission transaxle test port AWARNING Exceeding the pressure limits of the pressure probes and or adaptors can cause the equipment to burst PP 18 Pressure Probe Kit 4 Attach pressure probe to automatic transmission transaxle pressure test adaptor When installing the pressure probe into the appropriate adaptor do not overtighten the pressure probe 5 Using appropriate safety equipment lift vehicle to disengage drive wheels from ground or 6 Apply vehicle parking brake and block appropriate drive wheels according to gear selected for test Set the gear selector in neutral for a standard AWARNING transmission or park for an automatic transmission Set the parking brake If the vehicle has an automatic parking brake release disconnect the release mechanism for testing and reconnect when testing is completed Di
12. mall quantity of oil in open cylinder to seal any existing cylinder wall clearance 6 Perform Cylinder Compression Test again 7 Save results 8 Compare results of the initial test with the results of the second test Interpretation e No significant change in the ready position of the cylinder pressure waveform indicates piston ring integrity e A significant increase in the ready position of the cylinder pressure waveform indicates piston ring leakage Intake Integrity Test J For waveform interpretation information refer to Waveform Guidelines on page PP 11 1 Perform Cylinder Compression Test 2 Save results 3 Close engine throttle or manually block throttle body opening 4 Perform Cylinder Compression Test with closed throttle 5 Compare results PP 13 Pressure Probe Kit Interpretation e Significant change in the intake position of the cylinder pressure waveform indicates intake integrity e No significant change in the intake position of the cylinder pressure waveform indicates intake leakage Figure 4 Intake Integrity Test Exhaust Restriction An exhaust restriction can be detected on the cylinder pressure waveform J For waveform interpretation information refer to Waveform Guidelines on page PP 11 Interpretation e An unrestricted exhaust registers no significant pressure during the exhaust position of the cylinder pressure waveform A restricted exhaust registers significantly high
13. ntain adequate cranking speed a O Make sure the cylinder test adaptor does not have a Schrader valve in the end or test results will be invalid J When using the cylinder test adaptor the Schrader valve must be removed to obtain a valid pressure waveform PP 8 Test ACAUTION 3 Pressure Probe Kit Select Setup to set the following scope functions for standard testing Signal Channel 1 Aux 500 psi Channel 2 Off Pattern Sweep 1 sec or 500ms depending on viewing preference and cranking speed of engine Scale 250 psi Trigger Auto Run vehicle engine to achieve normal operating temperature e Do not touch hot engine components e Wear gloves when handling hot engine components The engine must be at normal operating temperature A cold engine will give low and inconsistent readings Complete this test before the engine cools Disable vehicle ignition system J For additional information refer to Disabling the 4 5 Ignition System at the end of this section Remove vehicle air cleaner Disable vehicle fuel system J For additional information refer to Disabling the Fuel 9 10 System at the end of this section Remove spark plug Attach cylinder pressure test adaptor to engine Attach pressure probe to cylinder pressure test adaptor Open engine throttle Crank engine through at least 6 compression cycles J Refer to vehicle manufacturer
14. of the vast number of test applications and variations in the products that can be tested with this instrument Snap on cannot possibly anticipate or provide advice or safety messages to cover every situation It is the automotive technician s responsibility to be knowledgeable of the system being tested It is essential to use proper service methods and test procedures and to perform tests in an appropriate and acceptable manner that does not endanger your safety safety of others in the work area or vehicle or equipment being tested It is assumed the operator has a thorough understanding of vehicle systems before using the pressure probes Understanding of these systems principles and operating theories is necessary for competent safe and accurate use of this instrument Use equipment only as described in this manual PP 1 Pressure Probe Kit Read All Instructions Read understand and follow all safety messages and instructions in this manual and on the test equipment Safety messages in this manual contain a signal word with a three part message and in some instances an icon The signal word indicates level of hazards in a situation e DANGER indicates an imminently hazardous situation which if not avoided will result in death or serious injury to operator or bystanders e WARNING indicates a potentially hazardous situation which if not avoided could result in death or serious injury to operator or bystanders e CAUTIO
15. oint B and levels out at point C A oro C B Figure 8 Internal Pressure Relief Valve Failure Filter Anti Drainback Valve Failure The engine must be at ambient temperature to accurately identify this condition The oil pressure waveform rises relatively slowly under this condition The oil pressure waveform will typically plateau midway and slowly level off at normal pressure Pa Figure 9 Filter Anti Drainback Valve Failure PP 17 Pressure Probe Kit Transmission Pressure Test The automatic transmission transaxle pressure waveform charts internal automatic transmission transaxle pressure fluctuations over a specific period of time and conditions A normal automatic transmission transaxle pressure waveform under high line pressure low gear D1 or reverse R is shown below Although minor variances occur depending on the design of the automatic transmission transaxle being tested the general characteristics of the normal automatic transmission transaxle pressure waveform always remains the same J Pump activity may create harmonics or jagged line at full pressure Figure 10 Normal Automatic Transmission Transaxle Waveform High Pressure Testing Tips O Under normal operating conditions the rise to full stable automatic transmission transaxle pressure typically takes less then one second When automatic transmission transaxle pressure testing is performed on a cold automatic transmiss
16. perature waveform with a slight variance due to the altered viscosity of the fluid thin line Figure 14 Restricted Filter 8 3563 2000 Snap on Tools Company Printed in U S A 2 00
17. rocedure for disabling the ignition system Some common methods of disabling the ignition system follow Disconnect primary wiring connector from ignition coil External Coils and Coil Wire Remove coil secondary wire from distributor cap and with a jumper wire connect it to a Known good ground Internal Coils Disconnect primary wiring connector from the distributor or from igniter module ECM PCM Power Fuse s Usually located in the fuse panel these fuses can be removed and the ignition may be disabled Distrubutorless Ignition IMPORTANT Be aware these fuses may supply keep alive memory and removing them may erase learned memory from the PCM Remove connector at ignition module igniters or coilpack s Usually located in the power distribution or maxi fuse panel this relay can be ignition Control Relay removed to disable the ignition system Usually located in the power distribution or maxi fuse panel this fuse can be lgnition Control Fuse removed to disable the ignition system PP 10 Pressure Probe Kit Waveform Guidelines a The cylinder pressure waveform charts the compression cycle of a cylinder Refer to the normal cylinder pressure waveform Figure 3 with open throttle Although minor variances occur depending on the design of the engine being tested the general characteristics of the normal cylinder pressure waveform always remains the same A low pressure reading at
18. sable fuel and ignition systems before testing AWARNING Check manufacturer s service manual for procedures 7 Start engine 8 Select appropriate gear Interpretation Examples Normal Automatic Transmission Transaxle Low Pressure A typical normal automatic transmission transaxle waveform under low pressure all gears except low gear D1 and reverse R is shown below ee ee Figure 11 Normal Transmission Transaxle Waveform Low Pressure Electronic Failure or Ball Seat Failure Under these conditions the automatic transmission transaxle pressure waveform typically registers sharp increases with a plateau or stair step pattern Figure 12 Ball Seat Failure PP 19 Pressure Probe Kit Worn Clutch Seal or Worn Band Servo Seal Restricted Filter The transmission transaxle must be at or below ambient temperature to accurately identify this condition At ambient temperature or below hyphenated line the automatic transmission transaxle pressure waveform rises slowly under both conditions Worn Seal When the automatic transmission transaxle reaches normal operating temperature the seals typically function normally and the automatic transmission transaxle waveform appears normal wide line Figure 13 Worn Seat Restricted Filter When the transmission transaxle reaches normal operating temperature the automatic transmission transaxle pressure waveform appears similar to the ambient tem
19. sducers hoses and adaptors should always be flushed with a solvent after any use to prevent the cross contamination of various fluids and systems air conditioning power steering transmission fluid brake fluid fuel coolant PP 3 Pressure Probe Kit Introduction Use the Sun pressure probe kits with the Pressure Probe Scope feature to test any vehicle system requiring pressure measurements and to view the pressure measurements over time There are three Sun pressure probe kits which can be used with any Sun Machine or Counselor II tester Each kit contains one pressure probe e 100 psi Pressure Probe Kit part number EAKO171L100A The 100 psi kit includes harness EAX0033L00A e 500 psi Pressure Probe Kit part number EAKO171L10A e 5000 psi Pressure Probe Kit part number EAKO171L20A Functional Description Figure 1 Pressure Probe and Harness A Pressure Probes 100 psi part number 2 16366 500 psi part number 2 16466 5000 psi part number 2 16566 B Pressure Probe Lead Part number EAX0033L00A Connects from the auxiliary extension lead not shown to the pressure probe A J Included with the 100 psi Pressure Probe Kit only The pressure probe lead kit may be ordered separately as part number EAK0O171L30A for use with the 500 psi and the 5000 psi Pressure Probe Kits PP 4 Pressure Probe Kit 100 psi System Pressure Probe Kit Possible Tests Fuel Injector Drop Tests Fuel pumps
20. the ready position of the cylinder pressure waveform indicates either a camshaft timing failure or an engine mechanical failure of piston rings valves head gasket J For additional information refer to Piston Ring Integrity Test to diagnose piston ring failure A high pressure reading at the ready position of the cylinder pressure waveform indicates either a camshaft timing failure or an excessive carbon build up on the cylinder head J For additional information refer to Camshaft Timing Failure to diagnose a camshaft timing problem Figure 3 Normal Cylinder Pressure Waveform A Ready Position Piston has stopped at TDC Cylinder contents are compressed Both valves are closed Allis ready for spark ignition B Power Position Both valves remain closed Piston has rapidly resumed movement Piston reaches top speed at the halfway point Piston quickly decreases in speed and stop at the end of the stroke C Vacuum 1 Position Piston has stopped at BDC Both valves remain closed Cylinder pressure has dissipated and the rapid down stroke of the piston has drawn a vacuum in the cylinder Exhaust valve is ready to open PP 11 Pressure Probe Kit PP 12 D Exhaust Position E Zero Position Exhaust valve has opened Piston has rapidly resumed movement Piston expels cylinder contents through the open exhaust valve Piston reaches top speed at the halfway
21. tion in the front of this manual and testing tips included with each test Pressure Probe Calibration Pressure probe must be calibrated before each use to maintain accuracy To perform pressure probe calibration select F10 to calibrate the pressure probe connected to the tester F9 to use the last good calibration if the pressure probe was recently calibrated and conditions have not changed J The scope stores calibration data from the last pressure probe calibrated until you exit the scope ora different pressure probe is selected and calibrated J Select F4 to recalibrate the pressure probe at any time Select Calibrate Pressure Probe from the Tools menu To maintain accuracy recalibrate the pressure probe if subjected to temperature changes during testing If a pressure probe fails to calibrate check all probe and cable connections PP 7 Pressure Probe Kit Cylinder Compression Test 7 Figure2 Optional Accessories A Cylinder Test Adaptor Connects from the quick coupler C to the vehicle Not included with kit B Brass Adaptor Connects from the pressure probe to the quick coupler C Not included with kit C Quick Coupler Connects from the brass adaptor B to the cylinder test adaptor A Not included with kit D Auxiliary Extension Adapts the timing auxiliary receptacle for use with pressure probes Not included with kit Testing Tips O Starter should be able to mai
Download Pdf Manuals
Related Search