I have a 2000 GMC Jimmy that I plan on bleeding the brakes using a pressure bleeder. I have the factory service manual and the directions says in to install J-39177 Combination Valve Pressure Bleeding Tool. Use the J-39177 in order to depress and hold the valve stem on the combination valve. The problem I have is that there is no valve stem protruding from the center of the fitting. I have the tool and installed it on the combination valve but since there is no valve stem protruding from the center of the fitting so there is nothing to depress. Can I put a piece of round metal in the center of the fitting than install the tool to depress?

 

If there was a failure in one of the hydraulic systems, the valve pin would be extended. It needs to be depressed so the valve stays centered while you're pressure bleeding it.

Was the hydraulic system opened between the master cylinder and the ABS unit? Did the master cylinder reservoir run dry? Do you have a scan tool that can initiate the automated bleed?

 

No failures at all, I was planning on flushing all of the brake fluid out with fresh brake fluid. The factory service manual says to install tool and use pressure bleeder. I found my answer through some web searching that says to insert a brass pin to depress the valve during brake bleeding.