Bench Bleed Master Cyl Question

mitch340Duster said
So unbelievably I have another update on this. Cleaned the garage real nice today, psyched about finally installing the master. Tried a bench bleed and SAME S**T AGAIN. No fluid pumping from the front reservoir and tight, choppy operation. WTF ?? After much head-scratching and troubleshooting I found that the culprit is the stop / lock bolt that screws into the bottom of the master. When it's tight it's locking-up the front piston. If I remove it everything works fine. When it's installed everything still works but only until the bolt is tightened, then it locks the piston up. The only purpose I can see that this bolt serves is to keep the pistons from coming out of the bore, which would be a bad thing however there's also a plate at the rear of the master (that the bellows attaches to) that essentially serves the same purpose. The only solution I can come up with is that instead of grinding down the original stop bolt, which would have worked but I didn't want to destroy it in-case I need it again some day, I got a new 14/28 x 1/2 bolt, cut it down shorter, and installed it with an 0-ring. No, I'm not crazy about this solution but it's NOT gonna work any other way. Another weird thing is the rebuild kit came with a lock bolt that is completely different from the original. (smaller diameter and it has a long pin end). If you ever have 10 hours to kill you can find similar unexplainable situations that I have encountered when re-assembling this car.

The tip of that bolt goes in a specific place to keep the front piston from returning too far.
It sounds like you had it on the piston instead.

This is a Ford master, but you can see how that bolt stops the front piston from returning further but allows it to go in to push fluid.
You have to push that front piston in a little against it's spring, then the stop bolt goes in.