|
|
Content .. 1760 1761 1762 1763 ..
4. Turn OD switch on. 5. Secure test gauge so it can be viewed from drivers seat. 6. Start engine and shift into D range. 7. Increase vehicle speed gradually until 3-4 shift occurs and note gauge pressure. 8. Pressure should be 524-565 kPa (76-82 psi) with closed throttle and increase to 690-896 kPa (100-130 psi) at 1/2 to 3/4 throttle. Note that pressure can increase to around 965 kPa (140 psi) at full throttle. 9. Return to shop or move vehicle off chassis dyno. PRESSURE TEST ANALYSIS CHART TEST CONDITION INDICATION Line pressure OK during any one test Pump and regulator valve OK Line pressure OK in R but low in D, 2, 1 Leakage in rear clutch area (seal rings, clutch seals) Pressure low in D Fourth Gear Range Overdrive clutch piston seal, or check ball problem Pressure OK in 1, 2 but low in D3 and R Leakage in front clutch area Pressure OK in 2 but low in R and 1 Leakage in rear servo Front servo pressure in 2 Leakage in servo; broken servo ring or cracked servo Pressure low in all positions Clogged filter, stuck regulator valve, worn or faulty Governor pressure too high at idle speed Governor pressure solenoid valve system fault. Refer Governor pressure low at all mph figures Faulty governor pressure solenoid, transmission Lubrication pressure low at all throttle positions Clogged fluid cooler or lines, seal rings leaking, worn Line pressure high Output shaft plugged, sticky regulator valve Line pressure low Sticky regulator valve, clogged filter, worn pump AIR TESTING TRANSMISSION CLUTCH AND BAND OPERATION Air-pressure testing can be used to check transmis- Air-pressure testing requires that the oil pan and valve 21 - 980 AUTOMATIC TRANSMISSION - 48RE - SERVICE INFORMATION DR/DH |