HD22 Component Check

^ Disconnect all of the air lines to the air compressor assembly drier.

^ Remove air compressor assembly from vehicle.

^ Remove air compressor drier cap (air lines are inserted into this part) from the drier assembly as outlined.

^ Is white filter material in air compressor drier cap oily?

YES -- GO to HD23.

NO -- REPLACE air compressor assembly and then REPEAT Service Bay Diagnostics. Reading and Clearing Diagnostic Trouble Codes