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Old 05-20-2012, 02:45 PM   #1
diabloceto
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Location: Byron, Ga
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*sigh* Brake help...

Okay I have a 1972 Chevy Cheyenne, with power brakes. I replaced the master cylinder, power booster, and prop valve with brand new ones. I bench bled the master cylinder and bled the brakes there is no air in the lines. I am still getting a hard pedal with very little travel. I can stop but even when I stomp the pedal the brakes won't lock up and when I press real hard the brake warning light comes on. I also checked the check valve it's good and I'm getting plenty of vacuum. Anyone have any suggestions how to solve this problem?
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Old 05-20-2012, 02:53 PM   #2
jocko
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Re: *sigh* Brake help...

sounds like you've covered all the obvious things, and then some. The ONLY thing that i could guess is a bad booster? (hard pedal). Sometimes when many things are replaced at once, there is a possibility that you get a bad new part. Could possibly be the check valve? As for the light coming on, that's an additional clue, but seems the only thing I can think of is under a hard stop the wire is shorting somewhere?? Or the new pressure diff sensor you installed is bad. Stinks when brand new, but could be the case.

Btw, there have been many posts about this crazy pressure diff pressure switch on these trucks - I'd love to see a pic side by side of one that is popped and one that is not.
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Old 05-20-2012, 05:21 PM   #3
cdowns
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Re: *sigh* Brake help...

adjust brake actuating rods by the factory service specs and you should b good
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Old 05-20-2012, 11:20 PM   #4
diabloceto
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Re: *sigh* Brake help...

adjust actuating rods, okay I'll try that out see if I can get her going in the right direction. I'll check and see if that's in my book. Thanks for the suggestions appreciate it.

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