Component Tests and General Diagnostics
Analysis of LeakageThe PTU may leak 3 different color fluids, red oil leak for an automatic transmission fluid (ATF) and brown-black gear lube for PTU fluid. The PTU seals prevent these types of fluids from leaking. It is important to note which color of fluid is leaking to conduct the most appropriate service procedure.
PTU Leaks From the RH Side
If the leak is red ATF, then the PTU intermediate shaft seal needs replacement. This is inside the bore of the PTU shaft behind the deflector.
If the leak is brown-black gear lube, then the PTU larger cover seal needs replacement. This is located on the PTU cover behind the deflector.
CAUTION: Remove and replace leaking seals using the information found in the intermediate shaft seal and deflector procedure. The specified tools called out in this procedure will allow seal replacement without causing damage to the PTU casing/drive gear.
PTU Leaks From the LH Side
If the leak is the red ATF, the compression seal needs replacement. This is between the PTU and transmission. Refer to Removal and Installation of PTU.
If the leak is brown-black, the PTU is overfilled and venting fluid from the top of the PTU. Flash and fill the PTU. Refer to PTU Draining and Filling.
