1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Brake Probs

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Old Dec 5, 2005 | 04:45 PM
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theNeanderthol's Avatar
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the torquinator
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From: Las Cruces, NM
Brake Probs

Hey guys. I know that we naturally have squishy brakes, but mine are getting worse. What do you guys think? When I set my foot on the brake, the pedal goes down till it builds pressure, but if I keep pressure on it, it keeps going down slowly, pretty much all the way to the floor. It usually doesnt happen when I'm driving, just when it is parked, but recently it has been doing it when I'm moving, and I have to either keep pushing harder and harder on the pedal to stop, or pump the brake. Pumping the brake builds up the needed pressure again.

It is getting a bit scary though. What do you think it is? The master cylinder?, the brake booster? I was planning on getting SS brake lines to give me a better pedal feel, but these symptoms couldn't be just flexing brake lines, right?
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Old Dec 5, 2005 | 04:50 PM
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Sounds like a vacuum leak in the master cylinder, when driving you're making more vacuum than when idling.
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Old Dec 5, 2005 | 04:59 PM
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From: SOUTH/WEST SUB.CHICAGO
its sounds like u may have a leak check your master cylinder calipers and ur wheel cylinders, its a easy job.
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Old Dec 5, 2005 | 05:29 PM
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If it is a fluid leak your fluid level in the reservoir would have dropped, I'm assuming that isn't the case or you would have mentioned it.
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Old Dec 5, 2005 | 06:18 PM
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From: Grand Rapids Michigan
Hey buddy. I'm sorry to say that you have the typical symptoms of a bad master cylinder. The slowly dropping pedal is a sign that the fluid is seeping past the seals.

Let me guess; if you push on it really hard, it doesn't drop very fast. But under light pressure (like sitting at a stop light) it will drop faster. Right?

Also, our brakes are not supposed to be squishy at all. Once you replace the MC (check at www.rockauto.com) and bleed the system you will be surprised at the results.

One other thing, bleeding can be a bit of a hassle sometimes. For a few dollars more you can also order some special bleeder nipples with built-in one-way valves that make brake bleeding a one man job and pretty much fool proof.

Good luck with it!
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Old Dec 5, 2005 | 07:31 PM
  #6  
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From: Columbiana, AL
i would change the master cylinder and bleed the hell out of the brakes.
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Old Dec 5, 2005 | 11:20 PM
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From: Las Cruces, NM
Sweet thanks guys Yeah Kentetsu, you hit the nail on the head. Thanks for all the help.
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