Diesel Data: Automotive Repair

Caster Close Valve Inspection: Overview

Cycle the CCV several times using a test lead connected to a 12 volt battery source. Gently blow through the top nipple with low pressure (approximately 1 psi) and check for a small leak. At 1 psi, no air should pass through the valve.





Warning:
Blowing more than 1 psi through the top of the valve can push the valve seal off the seat giving the appearance of a leak, and blowing into the side nipple will push the seal onto the seat, masking a potential leak.