Thread: Help with brakes!

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What about the pushrod between the booster and the master cylinder? I've got a similar setup with a 7" dual diaphragm booster and Corvette style master, but it's operating Willwood discs. It's seems to be common for the sellers of these items to not give you the proper pushrod to fit between the master and the booster. I'm using one that I made myself because I've never got the right one from a seller. The Corvette style master cylinder has a deep recess in the piston and requires a pushrod that's about an inch long. Some boosters come with a much shorter rod the barely protrudes from the booster. I've been sent a longer pushrod, that was supposed to fit the recessed cylinder, but it was too long. My solution was to use an allen head bolt, with a jam nut. My booster had 6mm threads.

The pushrod between these two parts is supposed to have a small amount of clearance, after the two are bolted together. If there's no clearance, pressure will build up and lock up the brakes, or at least cause some drag after awhile. You must also have a return spring on the pedal, or the same thing will happen.

My car requires a very small amount of pedal travel to produce a hard pedal, certainly less than an inch and a lot of that is just free play.