Comanche 4WD L4-150 25L VIN H TBI (1986) Transmission and Drivetrain Repair
Fluid Line/Hose: Service and Repair
FLUSHING OIL COOLER AND COOLER LINES
If a transmission or lockup clutch failure has contaminated the fluid, the oil cooler(s) should be reverse flushed to ensure that metal particles or
sludged oil are not later transferred back into the reconditioned transmission.
Procedure
1. Disconnect both cooler lines at the radiator.
2. Dislodge any foreign material at the inlet side of the cooler with a small screwdriver.
3. Reverse the flush cooler with a combination of mineral spirits and pulsating air under pressure (shop air).
4. Treat the cooler lines separately and make sure that they are clear by flowing mineral spirits or automatic transmission fluid through them.
5. Remove the leftover mineral spirits from the cooler and cooler lines by flowing automatic transmission fluid through them.
6. The cooler flow should now be checked by connecting the cooler tubes and placing the rear cooler tube into a one quart container. Overfill the
transmission by one quart. Watching a clock, start the engine (run at curb idle) and run it in neutral for exactly 20 seconds. If the cooler flow is less
than one quart in 20 seconds, replace the radiator or have the radiator bottom cooler professionally reconditioned.
NOTE: After completing any repairs that have involved draining the transmission fluid, add 5.7 liters (6 quarts) of AMC/Jeep/Renault or
equivalent Dexron II Automatic Transmission Fluid to the transmission before starting the engine.
7. Readjust the oil level.
