Section 07-01C: Transmission, Automatic, 4R70W | 1996 F-150 (4x2) (4x4) and Bronco Vehicles Equipped with 5.0L Engines Workshop Manual |
Transmission Fluid Cooler Flow Test
NOTE: The linkage, fluid and control pressure must be within specifications before performing this flow check.
Remove the fluid level indicator (7A020) from the fluid filler tube.
Place a funnel in the fluid filler tube.
Raise the vehicle.
Remove the fluid cooler tube from its fitting in the case.
Attach a hose to the fluid cooler tube and fasten the free end of the hose in the funnel installed in the fluid filler tube.
Start the engine and set idle speed at 1000 rpm with the transmission in NEUTRAL.
Observe the fluid flow at the funnel. When the flow is solid (air bleeding has been completed), the flow should be liberal.
When fluid flowing from the hose is in a steady stream, a liberal amount of fluid should be observed. "Liberal" is described as about 1 liter (1 quart) delivered in 15 seconds. If a liberal flow is observed, the test is complete.
Check both metal fluid cooler tube and fluid cooler inlet tube between the transmission and radiator (8005) for restrictions. Check for restrictions in the metal or rubber cooler lines to and from the auxiliary cooler, if so equipped. Visually check and physically feel all bends for kinks, especially rubber cooler lines, that would restrict flow and could result in transmission overheating or lack of lubrication.
To separate transmission concerns from cooler system concerns, observe the flow at the transmission case converter-out fitting.
Refer to Section 07-02 for diagnosis of the transmission fluid cooler.
Transmission Fluid Cooler — Backflushing/Cleaning
Conduct backflushing with a Rotunda Torque Converter/Oil Cooler Cleaner 014-00028 or equivalent. Test your equipment to make sure that a vigorous fluid flow is present before proceeding. Replace the system filter if flow is weak or contaminated.
To aid in attaching the cleaner to the transmission steel cooler lines, connect two additional rubber hoses to the transmission end of the steel transmission cooler lines as described below.
Turn on solvent pump and allow the solvent to circulate a minimum of 5 minutes (cycling switch on and off will help dislodge contaminants in cooler system).
Switch off the solvent pump and disconnect the solvent pressure hose from the transmission cooler return line.
Use compressed air to blow out the cooler(s) and lines (blow air into the transmission cooler return line) until all solvent is removed.
Remove the rubber return hose from the remaining steel cooler line.
Transmission Fluid Cooler Tube Replacement
When fluid leakage is found at the transmission fluid cooler (7A095), the transmission fluid cooler must be replaced. Refer to Section 07-02.
When one or more of the fluid cooler tubes must be replaced, each replacement fluid cooler tube must be fabricated from the same size steel tubing as the original fluid cooler tube.
Using the old fluid cooler tube as a guide, bend the new fluid cooler tube as required. Add the necessary fittings and install the fluid cooler tube.
After the fittings have been tightened, add fluid as needed and check for fluid leaks.