![]() |
![]() |
#1 |
Registered User
![]() Join Date: Feb 2004
Location: Groton, CT
Posts: 168
|
Brake Problem
I've got disc brakes in front and drum brakes on the rear of my 72' C-10. The rear brakes keep freezing in the braking position. I have a new master cylinder, an old booster and proportioning valve. The linkage from the cab to the booster appears to return to normal after the brake pedal is released but the rear brakes continue to ingage. Any ideas what might be causing this?
|
![]() |
![]() |
![]() |
#2 |
Licensed to Thrill!
Join Date: Apr 2006
Location: Northwest, GA
Posts: 1,673
|
Re: Brake Problem
Sounds to me like your prop. valve is holding pressure on them after you let off the brakes. The prop. valve for disc/drum acts like the residual pressure valve as well for your rears, so it could just be keeping the fluid held after you release.
Mike can fix you up with one for cheap if that's the problem. (He's a board vendor). www.bumpandgrindgarage.com Might want to listen to another person though before going with just my advice. DLB |
![]() |
![]() |
![]() |
#3 |
Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
|
Re: Brake Problem
you did bleed the brakes when the master was replkaced right?/well first i'd try cracking open one of the bleeders on the rear brakes to see if there is a pressure buildup //if not i'd pull the drums to see if theres excess build up of crapcrud on the backing plates preventing the shoes from retracting or if theres weak broken or damaged return springs
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY |
![]() |
![]() |
![]() |
#4 | |
Registered User
![]() Join Date: Feb 2004
Location: Groton, CT
Posts: 168
|
Re: Brake Problem
I'll check that out first as the proportioning valve is not new.
Thanks Quote:
Last edited by bossrod; 07-10-2007 at 03:03 PM. |
|
![]() |
![]() |
![]() |
#5 | |
Registered User
![]() Join Date: Feb 2004
Location: Groton, CT
Posts: 168
|
Re: Brake Problem
I bled the brakes and followed the steps to bleed the master. I'll check the rears but all the hardware is new. Could be the proportioning valve as mentioned above but I don't want to leave any stones unotuched.
Thanks Quote:
Last edited by bossrod; 07-10-2007 at 03:02 PM. |
|
![]() |
![]() |
![]() |
#6 |
Junior Member
Join Date: May 2007
Location: Fort Worth, TX
Posts: 47
|
Re: Brake Problem
If you do decide to get a proportioning valve, I did buy an aluminum nonadjustable one from Mike's Bump and Grind a few months ago and it worked great. It came with the bracket to mount up and new short lines to the master cylinder. I'm happy. All the other brake parts (master brake cylinder, rotors, calipers, pads, drum covers, spring kit, and shoes, everything new except lines) came from Oreilly. I could probably stand to replace the rubber parts, too. Check the rubber brake line on the rear axle, it could be deteriorating.
My truck stops really nicely now- but after I put all the new parts in I still had to blow compressed air through the lines, then rebleed, to get it to work right. My problem was that the rear brakes didn't seem to work at all even though everything was brand new. You might want to try that, too. Sorry for the rambling post.
__________________
72 C10 Long Bed, Vortec 350, Muncie M20, 3.73 Posi 79 Camaro, Vortec 350, Muncie M21, 3.90 Posi 07 BMW 328i, Wife's |
![]() |
![]() |
![]() |
#7 | |
Registered User
![]() Join Date: Feb 2004
Location: Groton, CT
Posts: 168
|
Re: Brake Problem
I'll keep that in mind if the proportioning valve is bad.
Thanks Quote:
|
|
![]() |
![]() |
![]() |
#8 |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
|
Re: Brake Problem
bossrod,
New recruit here. I was reading the different posts and happened to see yours with the brake problems. Did you find out what caused it? I had the same thing happen to my 69 some years back and after spending a whole weekend checking everything I could think of, I found out that the rubber brake line on top of the differential where it goes to the frame was the culprit. It had swelled up internally that it was allowing "pressurized" fluid to the brake drums but was not allowing it to go back causing the rear drums to lock up. Last edited by 68gmsee; 07-12-2007 at 11:55 PM. Reason: changed word |
![]() |
![]() |
![]() |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|