Author Topic: 69Z Brake Booster input shaft length???  (Read 828 times)

doomer

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69Z Brake Booster input shaft length???
« on: November 09, 2013, 12:03:32 AM »
I purchased a reproduction booster for my 69Z, and the input shaft (to the brake pedal) seems to be too long. I have yet to get it adjusted and not cause the brakes to drag. The rod makes contact with the pedal itself, preventing further shortening. I checked the rod length with my old booster, and the new one looks about 1" longer.

Any reasons why this would be so? There were different valve rod/input shaft lengths? Should I just cut the rod down? It's close.

Shane

doomer

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Re: 69Z Brake Booster input shaft length???
« Reply #1 on: November 09, 2013, 03:08:36 AM »
Well, I went ahead and cut it down. Everything works well now. Still wondering about the different rod length.  ???

jack92584

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Re: 69Z Brake Booster input shaft length???
« Reply #2 on: November 09, 2013, 04:37:59 AM »
I remember mine came with 2 shafts and I had to swap out the one that came in it. Maybe yours was missing the second one?
69 Z28 / Hugger Orange /  Deluxe Houndstooth  / M21 / 4:10 Posi / GM of Canada documented

JohnZ

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Re: 69Z Brake Booster input shaft length???
« Reply #3 on: November 09, 2013, 06:28:21 PM »
Most master cylinders for use with power brake boosters used a rear piston with a shallow hole for the booster-to-master pushrod, as the rod was captive and couldn't fall out. There were other applications (like '67 Corvette, among others) that used the same master cylinder for both manual AND power brakes, with a rear piston with a deep hole, which was required for use with manual brakes, so the pedal pushrod couldn't fall out of the rear piston on the manual application, and the booster for use with that master cylinder used a long booster-to-master pushrod. Photo below shows both the short and long booster pushrods.
'69 Z/28
Fathom Green
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