Air Pressure Test

Courtesy of FORD MOTOR COMPANY

NOTE: The center support contains an air bleed for the Low Reverse clutch. Some leakage during the air test can be normal.

NOTE: Scarf cut seals require hydraulic flow to seal properly some leakage during air test can be normal. The direct clutch uses 2 scarf cut seals.

A clutch concern can be located by substituting air pressure for fluid pressure to determine the location of the concern.

1.

Using a rubber tipped blow gun, apply 40 PSI (276 kpa) to the suspect clutch port for 2-3 seconds
- A dull thud indicates the clutch piston applied.
- A hissing noise may indicate a leak in the hydraulic passages. Hydraulic circuits that use scarf cut seals and/or air bleeds will have some normal leakage.

2.

While holding the blow gun nozzle firmly against the port in the transmission case, release the trigger.

3.

Wait 1-2 seconds.
- A hissing noise may indicate a leak in the hydraulic passages.

4.

4. Remove the blow gun from the port.
- A sudden release of air pressure indicates the hydraulic passages are capable of holding pressure.
- No noise may indicate a leak in the hydraulic passages.