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Booster push-rod failure: need help


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As you may remember, one of the last adjustments I made to my car before going to AMP was to adjust the brake master cylinder push-rod coming out of the booster. My final adjustment was about 1/4" longer than what you see in the photo. It was weird to me at the time that the rod had no lock nut. The brakes failed during the driving day at AMP while Matt Isbell was driving. In reviewing in-car video, there is a loud "pop" preceding the failure. Sorry the sound was so bad in the vid-I put the wrong lid on the gopro-it was a mechanical symphony in the flesh! I went looking for the cause of the failure, of course, at the point of my most recent car work: the booster rod. It looks like the adjuster failed and compressed completely into the push-rod. Has anyone else ever had this problem? And, how about some repair recommendations that will be a lot stronger? The threads in the adjuster look fine, so I'm betting that the female end of the rod has a crack in it (gotta figure out how to get that thing out of there). I was hoping to autocross this Saturday-now I feel that opportunity slipping away. Help! This is a stock '72 240z booster that I put new seals in years ago and a 15/16" master cylinder. The rod is the stock 240z part.

 

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Edited by RebekahsZ
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We did this set up in our old car and found that you needed the zx longet end  , the 240 one is about 1/2 in shorter and you have to run it out to the end to work this puts a large load on it the zx one is longer and is threaded in much further, I dont remember if we used the whole rod or just the end (I think just the end)

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Anybody know how to get the rod out? This booster just has a rubber seal around the rod with no visible metal retainer.

 

Grab the push rod with vice grips and pull it out. See picture for components.  Be carefull not to loose the reaction disk (glue in-place when reassembling the push rod).

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