So I replaced my brake master cylinder with an AC Delco one from Rock Auto. Now my brakes drag at all four corners. I've bought a brake booster adjustment tool and measure the the distance between brake booster rod and master cylinder piston and it appears I'm 3/8" too long. It appears our booster isn't adjustable. Is this normal for an OEM part to not fit. I didn't have anything wrong with the original brake master cylinder and I'm thinking of putting it back in but I have 218,000 miles on it. All I'm looking for is a new brake master cylinder to that fits the original brake booster. I got the original brake booster rebuilt. Thanks!

 

Just a random question because of the craziness of the different brake systems. Is the new one for the JL9 with Brembos?

I'm not sure if there are differences, but given what you measured I'd guess there is.

 

I just looked up the alternate part # on the AC Delco mc I bought from Rock Auto and it doesn't match. So I don't think this master cylinder is for the JL9. I just got a part # off the original brake mc & it's 25920077. The Raybestos master cylinder matches the original part # so I will be ordering that. So it looks like this is solved thank you!

 

I just looked up the alternate part # on the AC Delco mc I bought from Rock Auto and it doesn't match. So I don't think this master cylinder is for the JL9. I just got a part # off the original brake mc & it's 25920077. The Raybestos master cylinder matches the original part # so I will be ordering that. So it looks like this is solved thank you!