Air Pressure Test

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

Courtesy of FORD MOTOR COMPANY

Item	Description
1	Intermediate clutch (C) port
2	Low/reverse clutch (D1) port
3	Not used
4	Direct clutch (B) port
5	Overdrive clutch (E) port
6	Forward clutch (A) port
7	Thermal bypass valve

A no-drive condition can exist with correct transmission fluid pressure because of inoperative clutches. Refer to the Clutch Application Chart to determine the appropriate elements. A clutch concern can be located through a series of checks by substituting air pressure for fluid pressure to determine the location of the concern.

Example: When the selector lever is in a forward gear range, a no-drive condition may be caused by an inoperative clutch.

1.

Drain the transmission fluid. Remove the transmission fluid pan.

2.

Remove the transmission fluid filter, seal assembly and mechatronic unit.

3.

Locate the inoperative clutches by applying air pressure into the appropriate clutch port.

4.

Apply air pressure to the appropriate clutch port. A dull thud may be heard or movement felt when a clutch piston is applied. If the clutch seals or check ball are leaking, a hissing sound may be heard.

5.

If the clutches fail to operate during the air check:
- the piston seals are not seated, damaged or installed incorrectly.
- plugged feed holes for clutch apply in the case and/or clutch cylinder.
- damaged piston and/or clutch cylinder.

6.

Service as required and recheck.