Brake problem
Thread Starter
Pro
Joined: Aug 2000
Posts: 666
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From: Richmond TX
Brake problem
Got a strange problem with my brakes on my 85...just cleaned up all the suspension and brakes, installed new pads, bled the brakes. Now when I take it out to test the brakes, thes seem slow tostop the car. I have to pump them once, and only once, and they seem to grab a lot better. If I don't pump them the one time, and continue to push on the pedal, it almost gets to a stop, and then the motor will rev up about 300 rpm, and start moving again. If I pump the one time, they seem to stop just fine. I've beld them again, but the same problem. I could probably live with pumping them once, but why does the moter rev when I try to stop??? :crazy: :crazy:
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Re: Brake problem (mk842766)
:cheers: Sounds like a vacuum leak!
Did you disturb the hoses around the booster?
:seeya
Did you disturb the hoses around the booster?
:seeya
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Re: Brake problem (mk842766)
If they were working fine before the job and not working correctly after, then it is probably something you did/ didn't do. I assume you bled them in the correct order. I agree with Jack as it sounds as if air is trapped in the system. Also, did you change out the rubber brake lines? The inner rubber may be collapsing causing a restriction of fluid. However, I'm leaning more toward trapped air. Bleed her again. :D
Melting Slicks
Joined: May 2001
Posts: 2,143
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From: San Diego CA
Re: Brake problem (mk842766)
It's possible that when you were bleeding the brakes that you pushed the master cylinder piston past it's wear area and scuffed the o-rings.
When you pump the brakes the second time, do they stay firm or does the pedal slowly go down. This would be an indication that the fluid is leaking around the seals.
If the fluid in the MC reservoir got low while you were bleeding the system some air could have been sucked in and be pretty far up in the brake lines.
When you pump the brakes the second time, do they stay firm or does the pedal slowly go down. This would be an indication that the fluid is leaking around the seals.
If the fluid in the MC reservoir got low while you were bleeding the system some air could have been sucked in and be pretty far up in the brake lines.
Thread Starter
Pro
Joined: Aug 2000
Posts: 666
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From: Richmond TX
Re: Brake problem (John Row)
They stay firm, and stop as before...it's just the slow stop if I don't pump, and the increase in engine RPM that worry me...I would agree that it sounds like vacuum, but I always thought that plugging a leak would increase the RPM...therefore, I would assume I have a leak, and when I depress the brake hard enough, I plug that leak, thus resulting in an increase in RPM. Sounds like a booster problem to me, but the brakes are not hard to engage???? hope to chase it down...... :banghead:
Racer
Joined: May 2001
Posts: 252
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From: VillaPark,IL U.S.A. IL
Re: Brake problem (mk842766)
Strange mine are doing about the same thing. Not sure about the 300 rpm increase though. I bled mine and they felt fine until I started the car and they got real soft. Bled them again not much better. I ran the race that I was in at Atlanta and about half way through the pedal hit the floor at the end of the back straight at 155. :eek: :eek: :eek:
Saturday I put all new pads on and bled them again still seem the same. I was going to just replace the master and front calipers and hope this works. Its not a good feeling doing 150 and having your foot go to the floor.
If it was a vaccum leak would'nt that make the pedal harder to press??
Any info would be greatly app.
Chuck http://www.tccracing.com
#72 :flag
[Modified by 72tccracer, 6:07 PM 4/28/2003]
Saturday I put all new pads on and bled them again still seem the same. I was going to just replace the master and front calipers and hope this works. Its not a good feeling doing 150 and having your foot go to the floor.
If it was a vaccum leak would'nt that make the pedal harder to press??
Any info would be greatly app.
Chuck http://www.tccracing.com
#72 :flag
[Modified by 72tccracer, 6:07 PM 4/28/2003]
