03-26-2008, 10:02 AM | #1 |
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Join Date: Mar 2007
Location: Oregon
Posts: 109
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Quick brake question
Tonight while driving my Chevy, the brake warning light came on. At the same time the brake pedal became sort of stiff, as if the power booster quit working. After I applied the brakes a few times the light went off and the pedal returned to normal. It did this twice on the way home, and the master was full of fluid. My master cylinder is only about 8 months old, the back brakes are pretty worn but the front disc pads are still good. Any ideas on this before I tear into it?
Colby. 1972 K20 4x4 350 sm465 |
03-26-2008, 01:21 PM | #2 |
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Join Date: Jul 2001
Location: Muskegon,MI,USA
Posts: 6,026
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Re: Quick brake question
From your description, I would suspect the rear brakes caused the prop valve to lock out which would account for the stiff pedal. When you pumped the brakes the prop valve reset so that it felt normal again. It is possible for the wheel cylinders to stick over time and then release which can cause the prop valve to go into action.
I would start by redoing the rear brakes either replacing or rebuilding the wheel cylinders at the same time. Jim
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1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC |
09-14-2009, 01:46 PM | #3 | |
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Join Date: May 2008
Location: Central Iowa
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Re: Quick brake question
Quote:
so does it sound like a bad booster, or bad prop valve?
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gone: --'07 Tahoe LTZ 4WD --'68 Firebird 400 Convertible gone: --'72 Chevy K20 Last edited by 72-c20; 09-14-2009 at 01:46 PM. |
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09-15-2009, 09:25 PM | #4 |
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Join Date: May 2008
Location: Central Iowa
Posts: 459
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Re: Quick brake question
bump? lots of brake question posts, and this one actually fits my symptoms exactly, but no resolution was posted....
anyone? some time before this happened, all my brakes were redone, and functioning properly....
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gone: --'07 Tahoe LTZ 4WD --'68 Firebird 400 Convertible gone: --'72 Chevy K20 |
09-15-2009, 10:52 PM | #5 | |
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Re: Quick brake question
Quote:
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I'm Just like my truck. Old, Ugly and Grouchy. Except my truck starts easily in the morning and doesn't smoke! IT'S NOT EASY BEING GREEN! -Kermit the frog 1970 Chevrolet C-10 Longbed Stepside : 350, Muncie M20, 3.08 GM corp. positraction Forest green exterior/light green interior(Where all my money goes) 1996 Toyota Corolla (Parts runner) |
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09-16-2009, 09:16 AM | #6 |
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Join Date: May 2008
Location: Central Iowa
Posts: 459
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Re: Quick brake question
wheel cylinders are new.... well, at least one is..... hmmm....
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gone: --'07 Tahoe LTZ 4WD --'68 Firebird 400 Convertible gone: --'72 Chevy K20 |
09-16-2009, 11:03 AM | #7 |
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Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
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Re: Quick brake question
Rear brake issue. Check the adjustment. If they are too far adjusted, the excess fluid demand will kick the prop valve and do exactly what you're describing.
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