E 350 1 Ton Van V10-6.8L VIN S (1997)
Transmission Cooler: Component Tests and General Diagnostics
NOTE: The transmission linkage/cable adjustment, fluid level and line pressure must be within specification before performing this test.
1. Remove the fluid level indicator from the fluid filler tube.
2. Place a funnel in the fluid filler tube.
3. Disconnect the fluid cooler return tube (rear fitting) from the Cooler Bypass Valve (CBV) on the transmission.
4. Connect one end of a hose to the fluid cooler return tube and route the other end of the hose up to a point where it can be inserted into the funnel in
the fluid filler tube.
5. Insert the end of the hose into the funnel.
CAUTION: Make sure the hose is secure.
6. Start and run the engine at idle with the transmission in the neutral range.
7. Watch the fluid flowing from the hose. When the fluid flow is all liquid, remove the hose from the funnel, placing it into a large clean bucket for
30 seconds, and then place the hose back into the funnel.
8. Stop the engine.
9. Remove the hose and reconnect the rear fluid cooler tube to the CBV.
10. Measure the amount of transmission fluid in the bucket. An adequate flow is approximately 1.0 L (1.057 quarts) delivered in 30 seconds. If
adequate flow is observed, the test is complete. Top off the transmission fluid level to the normal operating level and reinstall the fluid level
indicator.
11. If the flow is not adequate, disconnect the front fluid cooler tube (converter out) from the CBV.
12. Connect a hose to the converter-out-to-cooler inlet on the CBV.
13. Repeat Steps 5 through 8. If the flow is now adequate as described in Step 10. If the flow is not adequate, internal transmission repair is required.
Possible cause is the pump, converter assembly or both.
