Front Disc Brakes Dragging - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-04-2013, 07:20 PM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Front Disc Brakes Dragging

I've got a 1937 Dodge pickup setting on a 1989 S10 Frame.

The trucks got over 7000 miles with no braking problems until last week when the front brakes started dragging slightly. They start dragging after heating up, no problems when cool. When they start dragging I can jab the pedal a few times and they will release. After the brakes cool slightly there is no excess drag. The master is a Corvette style dual so if the pedal or piston were hanging up then the front and rear should be dragging. Both front brakes have an equal amount of drag and there is no pulling left or right when the brakes are applied.

I thought it might be the residual valve but it's several feet from the calipers and not affected by heat. I could see one caliper dragging because the piston was sticking but both have the same amount if drag like the pressure is not being released completely.

Stock disc up front
2001 Blazer rearend with disc
Corvette style dual master cylinder-mounted under the floor with 8" booster
Front 2lb residual valve
Rear 2lb residual valve with proportional valve
All new steel lines
All new flex lines

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-04-2013, 10:58 PM
aosborn's Avatar
Registered User
 
Last wiki edit: Suspension: designs, shapes, sizes Last photo:
Join Date: Oct 2008
Location: Lakewood, WA
Posts: 621
Wiki Edits: 7

Thanks: 0
Thanked 17 Times in 16 Posts
You might check the pushrod clearance between the booster and the master cylinder to see if it is a bit too tight. With a proportioning valve in the system the pedal pressure could be affecting the front more than the rear, especially if the dragging is minor.

Regards,

Andy
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-05-2013, 04:15 PM
Pantaz's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Van Nuys, CA
Posts: 96
Wiki Edits: 0

Thanks: 4
Thanked 3 Times in 3 Posts
I usually find dragging caused by dirt build-up around the caliper pistons. But you say this is only happening after the brakes get warm. Perhaps it's brake fluid contamination? Couldn't hurt to flush and refill the system.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-05-2013, 05:08 PM
Registered User
 
Last photo:
Join Date: Mar 2012
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ck the Bleed hole in the master for the affected circuit.
If this hole is plugged it can't compensate for fluid expansion, from heat, or pad wear and the only place the pressure can go is the caliper pistons.
It would cause these symptoms for sure.
Just a guess, and yes it can affect one circuit and not the other.
I'd still do what aosborn said an ck the push rod too.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-06-2013, 12:41 AM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
It was the pushrod clearance. I can't figure out why it took so long to be a problem. I jacked it up when the brakes were dragging and less than one turn of the MC mounting nuts was enough to release the pressure.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-07-2013, 12:04 AM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Well it looks like it wasn't the pushrod length because it did it again today. I stabbed the pedal a few times and it was ok the MC piston must be sticking a little, will be replacing it next.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-07-2013, 07:23 AM
Registered User
 
Last photo:
Join Date: Mar 2012
Posts: 24
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I can't stand that, you think you got it an Bam, nope not it.
Have you cracked open one of the bleeders, when the brakes start to drag?
Just to see if it is in-fact something up line causing your problem?
How do you know it's not the residual valve?
I'd even crack open the fitting at the M/C to narrow things down.
Like, if you did and found too much or pressure at X then you'd be sure.
Know what I'm saying...
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-07-2013, 08:28 AM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by BigEsGarage View Post
I can't stand that, you think you got it an Bam, nope not it.
Have you cracked open one of the bleeders, when the brakes start to drag?
Just to see if it is in-fact something up line causing your problem?
How do you know it's not the residual valve?
I'd even crack open the fitting at the M/C to narrow things down.
Like, if you did and found too much or pressure at X then you'd be sure.
Know what I'm saying...
The residual valve was my first thought even picked up a new one. I was sure it was the pushrod because the brakes released when I loosened the MC mounting nuts. I'll try cracking a fitting on the MC since both wheels are dragging.

I've had brake problems ever since cheap import parts took over, had 2 brand new Oreillys wheel cylinders fail on one car and a pressure switch fail on this one both resulting in brake failure. When I installed the Blazer rear end on this ride I rebuilt both calipers and both dragged because the O-rings where too large making the pistons stick.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-03-2013, 08:39 PM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Ok, I've replaced the MC, front calipers and added an ever stronger return spring but still having some issues. After a few stops the brakes "pump up a little" less pedal travel. If I stab the pedal hard the problem goes away. There's not as much brake drag as before but there's still more than I like.

A few months ago I did replace the original 7" dual booster with a new 8" dual booster, they're both the universal style with the same bolt pattern.

Anyone ever heard of a dual booster hanging up?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-04-2013, 09:04 PM
Member
 
Last photo:
Join Date: Dec 2004
Location: ohio
Age: 67
Posts: 610
Wiki Edits: 0

Thanks: 0
Thanked 35 Times in 32 Posts
Check the adjustment of the pushrod from the booster to the master cylinder.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-04-2013, 09:13 PM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
There's about a 1/32 space to be sure it was not touching when released.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-12-2013, 06:52 AM
Registered User
 
Last photo:
Join Date: Mar 2011
Posts: 139
Wiki Edits: 0

Thanks: 11
Thanked 9 Times in 8 Posts
Loosen the top caliper mounts to the spindles when hot and see if they release.. I had to slightly shim the top mounting bolts on my scarebird mounts...
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 04-15-2013, 01:31 PM
Registered User
 
Join Date: Jan 2012
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I finally figured out the problem, it was an 8" dual booster I had installed before replacing the rear end. At first I did not have any problems but after awhile the front brakes started dragging.

I'd contacted the company that sold me the booster and their tech said there's no way it was the booster.

A few weeks ago I decided to put the 7" dual back on and the problem went away immediately.

The 8" booster was purchased off ebay from "gonefishing69", their customer service is the worst I've dealt with ever! I've called them several times about the problem they finally agreed to sell me another booster for $30.00, they stated that "several people were sending them boosters from salvage yards for refunds/returns”. Even though I had proof of purchase they would not replace the booster, even though it's only been 4 months, the problems actually started about five weeks after receiving it.

I do not recommend purchasing any items from "gonefishing69" on ebay.
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
67 Camaro Front Disc Brakes Trevor Horn Suspension - Brakes - Steering 3 03-22-2007 10:00 PM
front disc brakes john p Suspension - Brakes - Steering 3 12-31-2006 12:50 PM
70 suburban front disc brakes jose a roman jr Suspension - Brakes - Steering 23 04-02-2006 04:13 PM
front disc brakes for 57 Chevy Bamaham Introduce Yourself 2 11-07-2004 02:29 PM
Front Disc Brakes 35 Ford Rancher Suspension - Brakes - Steering 2 05-24-2002 07:18 PM


All times are GMT -6. The time now is 08:28 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.