Ford F-150 2002 - Transmission Fluid Cooler Flow Test; Fluid Cooler Flow Test Procedure

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housing for evidence of fluid leakage. Raise the vehicle on a hoist and run the engine at fast idle, then at engine idle, occasionally shifting to the OVERDRIVE

and REVERSE ranges to increase pressure within the transmission. Observe the front of the flexplate, back of the cylinder block (in as far as possible), and

inside the torque converter housing and front of the case. Run the engine until fluid leakage is evident and the probable source of leakage can be determined.

Leak Check Test with Black Light

Oil-soluble aniline or fluorescent dyes premixed at the rate of 2.5 ml (1/2 teaspoon) of dye powder to 0.24 L (0.5 pint) of automatic transmission fluid have proven

helpful in locating the source of fluid leakage. Such dyes can be used to determine whether an engine fluid or transmission fluid leak is present, or if the fluid in the

transmission fluid cooler hose is leaking into the engine coolant system. An ultraviolet light must be used to detect the fluorescent dye solution.

Transmission Fluid Cooler

CAUTION: Whenever a transmission has been disassembled to replace worn or damaged parts, the cooler bypass valve (CBV) and transmission fluid

cooler lines must be cleaned and backflushed.

NOTE: Cleaning and backflushing the transmission fluid cooling system, along with following all the normal cleaning and inspection procedures during disassembly and

reassembly will keep contamination from entering the transmission, causing a repeat repair.

When internal wear or damage has occurred in the transmission, metal particles, clutch plate material, or band material may have been carried into the torque converter

and transmission fluid cooler. These contaminants are a major cause of recurring transmission troubles and must be removed from the system before the transmission

is put back into use.

Transmission Fluid Cooler Flow Test

NOTE: The transmission linkage/cable adjustment, fluid level and line pressure must be within specification before carrying out this test. Refer to Fluid Level Check

under Verification of Condition in this section. Refer to Line Pressure Test under Special Testing Procedures in this section. For shift linkage/cable adjustment

procedures, refer to Section 307-05.

1. Remove the fluid level indicator from the fluid filler tube.

2. Place a funnel in the fluid filler tube.

3. Raise and support the vehicle.

4. Disconnect the cooler return tube (rear fitting) from the transmission cooler bypass valve (CBV). Refer to Section 307-02.

5. Connect one end of a hose to the cooler return tube and route the other end of the hose up to a point where it can be inserted into the funnel at the fluid filler

tube.

6. Remove the supports and lower the vehicle.

7. Insert the end of a hose into the funnel.

8. Start the engine and run at idle with the transmission in NEUTRAL.

9. Once a steady flow of fluid (without air bubbles) is observed, remove the hose from the funnel and place the hose in a measuring container for 15 seconds. After

15 seconds place the hose back into the funnel and turn the engine off. Measure the amount of fluid in the container. If adequate flow was observed,

approximately 946.24 ml (32 oz) will be in the measuring container; the test is now complete.

10. If adequate flow is not observed, turn off the engine. Disconnect the hose from the cooler return line (transmission inlet).

11. Disconnect the fluid cooler line from the front case fitting and connect the hose to the case fitting (converter out) and repeat Steps 6, 7, and 8.

12. If adequate flow from the transmission is observed, look for a plugged cooler line and/or fluid cooler. Refer to Section 307-02 for diagnosis of the transmission

fluid cooler.

13. If adequate flow is still not observed, repair and/or installation of a new pump and/or torque converter may be required.

For transmission fluid cooler tube replacement, refer to Section 307-02.