Transmission Cooler: Service and Repair

^ Tools Required:
- J 35944A Transmission Oil Cooler and Line Flusher
- J 35944-22 Cooler Flushing Fluid

NOTICE: The automatic transmission oil cooler flushing procedure must be performed whenever a transmission is removed for service to remove existing oil which may be contaminated and to prevent the contamination of the new oil. The flushing procedure must be performed before installation of the overhauled or replacement transmission.

Important:
- J 35944A "Transmission Oil Cooler and Line Flusher" is designed for use with only J 35944-22 "Cooler Flushing Fluid." Use of any other fluid can result in damage to the tool, transmission oil cooler components or improper flushing of the cooler. After overhauled or service replacement transmission is installed in vehicle, do not connect oil cooler lines until flushing procedure is completed.

1. Remove fill cap on J 35944-A and fill with 0.6 liters (20 to 21 ounces) of J 35944 22.
- Do not overfill.
- Follow manufacturer's suggested procedures for handling fluid.

2. Replace cap on J 35944A and pressurize to 550 to 700 kPa (80 to 100 psi).

NOTICE: Shop air supply must be equipped with a water/oil filter and pressure should not exceed 825 kPa (120 psi). Failure to use a water/oil filter can allow residual moisture to cause corrosion of components. Excessive air pressure can cause damage to components.

3. Install J 35944A to undercarriage of vehicle with hook provided, and attach hose from flushing tool to upper pipe (856) attaching to top fitting at transmission end of oil cooler.
4. Install discharge hose to lower pipe (857) attaching to bottom fitting at transmission end of oil cooler. Clip opposite end of discharge hose to oil drain container.
5. With water valve off on J 3594~A, attach water supply to J 3594A.
6. Turn water supply on at faucet.
7. Flush transmission fluid by opening the water valve on J 35941A for about 10 seconds.
- If water does not flow through cooler (system is completely plugged), do not complete flushing procedure. Turn water off immediately and inspect oil cooler and pipes for restriction. Replace cooler and/or pipes if needed.
8. Turn water valve off on J 35944-A and clip discharge hose to 5-gallon in pail. Cover pail with shop cloth to prevent splash.
9. Turn water valve on J 3594A on and depress trigger to mix flushing fluid into water flow.
- Use bale clip to hold trigger down.
10. Flush oil cooler with water and fluid for two minutes.
- Every 15 to 20 seconds during flushing procedure, attach air supply to air valve on J 35944-A and leave in place for 3 to 5 seconds to create surging action for complete cleaning.
11. Release trigger and turn water valve off on J 35944A.
12. Disconnect discharge hose from lower pipe (857).
13. install hose from J 35944A to lower pipe (857) attaching to bottom fitting of oil cooler.
14. Connect discharge hose to upper pipe (856) attaching to top fitting of oil cooler.
- Reversing hoses creates back-flush.
15. Repeat steps 9 and 10.
16. Release trigger and allow water only to rinse the oil cooler for one minute.
17. Turn water valve off on J 35994A and turn water supply off at faucet.
18. Attach air supply to air valve on J 35944A and dry system out with dry compressed air for at least two minutes. Be sure no moisture can be seen leaving hose.
19. Remove J 35944A and discharge hose from oil. cooler pipes.
20. Connect oil cooler feed pipe to automatic transmission. Feed pipe is lower pipe (857) attached to bottom connection at transmission end of system.
21. Attach discharge hose to oil cooler return pipe.
- Return pipe is upper pipe (856) attached to top connection at transmission end of system.
22. Attach opposite end of discharge hose to oil drain container.
23. Fill automatic transmission with fluid.
24. Start engine and run for 30 seconds to remove any residual moisture from cooler.

Inspect
a. Fluid flow through cooler feed lines during 30 second running period. Minimum of 1.8 liters (2 quarts) of fluid should flow during this time.
b. If fluid flow is insufficient, check flow by disconnecting feed line at cooler and observe flow with engine running at idle.
- Insufficient Flow: Inspect transmission for causes.
- Sufficient Flow: Inspect cooler pipes, hoses and fittings and repeat cooler flushing procedure. If the flow through cooler is still insufficient after second flushing procedure, replace cooler.

25. Disconnect discharge hose.
26. Connect oil cooler return pipe to fitting.

Adjust
- Transmission fluid level.