Fluid Line/Hose: Service and Repair

OIL COOLERS AND TUBES FLUSHING

When a transmission or lock-up clutch failure has contaminated the fluid, the oil cooler(s) should be reverse flushed to insure that metal particles or sludged oil are not later transferred back into the reconditioned transmission.
(1) Disconnect both cooler lines at radiator.
(2) Dislodge any foreign material at the inlet side of the cooler with a small screwdriver.
(3) Reverse flush the cooler with a combination of mineral spirits and pulsating air under pressure (shop air).
(4) Treat the cooler lines separately and insure they are clear by flowing mineral spirits or automatic trans mission fluid through them.
(5) Remove leftover mineral spirits from cooler and cooler lines by flowing automatic transmission fluid through them.
(6) Cooler flow should now be checked by connecting the cooler tubes and placing the rear cooler tube into a 1 quart container. Overfill the transmission by 1 quart. Watching a clock, start engine (run at curb idle) and run in neutral for exactly 20 seconds. If cooler flow is less than 1 quart in 20 seconds, replace the radiator or have the radiator bottom cooler professionally reconditioned.