TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > Suspension, Steering, Brakes & Wheels
  New Posts New Posts RSS Feed - All 4 breaks seize up?!?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

All 4 breaks seize up?!?

 Post Reply Post Reply Page  <123>
Author
Message
70javluvr View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Dec/22/2007
Location: Canada
Status: Offline
Points: 603
Post Options Post Options   Thanks (0) Thanks(0)   Quote 70javluvr Quote  Post ReplyReply Direct Link To This Post Posted: Sep/06/2014 at 9:14am
after getting back home I jacked both ends up in the air and tried to turn all for wheels all were locked.  Rubber hoses are new and don't see that being problem but could be a cheap check.  MC has a small large configuration for disc breaks.  Any dance it could be the booster or check valve itself I have never seen one of these fail but what would be the result and how would you check for it?


70 Javelin Donohue Tribute car Sonic Silver/Shadow Mask/360/Custom Interior
Back to Top
tyrodtom View Drop Down
AMC Addicted
AMC Addicted


Joined: Sep/14/2007
Location: Virginia
Status: Offline
Points: 6199
Post Options Post Options   Thanks (0) Thanks(0)   Quote tyrodtom Quote  Post ReplyReply Direct Link To This Post Posted: Sep/06/2014 at 9:36am
Just because the master cylinder has the small, and large reservoir, doesn't necessarily prove it's a disc. brake master cylinder.

Leaving the master cylinder uncovered for several days will result in moisture contamination. Brake fluid is hygroscopic, readily takes on moisture from the surrounding air.

Normal brake fluid boils at about 450 degrees, I use some in my race car that boils at about 600.

If you get moisture in you brakes fluid, it separates from the fluid and boils to steam at 212, you can easily reach that temperature in a normal stop.

The steam expands and locks the brakes.

This can cause a problem even with nothing else wrong with your brakes, one brake application will heat the fluid enough that from that point on the pads never fully retract, and the fluid keeps getting hotter till more of the moisture goes to steam and finally developes enough steam pressure to lock all the brakes.
66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va.
Back to Top
pit crew View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Jul/08/2007
Location: delete
Status: Offline
Points: 5341
Post Options Post Options   Thanks (0) Thanks(0)   Quote pit crew Quote  Post ReplyReply Direct Link To This Post Posted: Sep/06/2014 at 9:45am
Could it be something as simple as the brake Z bar linkage being rusty enough that it is sticking? We had a 74 Javelin in the shop the other day where after the owner pulled a panic stop it locked up the brakes. Turns out the Z bar pivoted more than normal into a rusty area where it promptly froze in place. 

73 Hornet - 401EFI - THM400 - Twin Grip 20
Back to Top
FuzzFace2 View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/05/2007
Location: Angier, N.C.
Status: Offline
Points: 10343
Post Options Post Options   Thanks (0) Thanks(0)   Quote FuzzFace2 Quote  Post ReplyReply Direct Link To This Post Posted: Sep/06/2014 at 10:55am
Originally posted by pit crew pit crew wrote:

Could it be something as simple as the brake Z bar linkage being rusty enough that it is sticking? We had a 74 Javelin in the shop the other day where after the owner pulled a panic stop it locked up the brakes. Turns out the Z bar pivoted more than normal into a rusty area where it promptly froze in place. 

When I went and took my 70 Javelin z bar apart for cleaning & paint I found the same thing.

OK happens to all 4 wheels and the car has 3 new hoses so I would say it is not the hoses.

Could it be water in the fluid boiling the cause? Guess it could be could try flushing/bleeding the brakes again to get it out.

If it was 1 of the pedal rods too long guess as a test when it happens again loosen the master to see if that helps. If so then 1 of the rods is too long.

If that does not help the try cracking the brake lines at the master to see if it will bleed of the psi. If that helps and the fluid has been flushed then I would say bad master.
Dave ----
TSM = Technical Service Manual

75 Gremlin X v8 for sale
70 Javelin 360/auto drag car
70 Javelin 360/T5 Street car
Back to Top
Mopar_guy View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Jun/07/2009
Location: Ohio
Status: Offline
Points: 4805
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mopar_guy Quote  Post ReplyReply Direct Link To This Post Posted: Sep/06/2014 at 12:16pm
Here's my 2 cents - First off the system needs flushed of the contaminated fluid. Leaving that lid off is a HUGE no-no. It can be done after you troubleshoot this problem but it must be done.
To troubleshoot this properly, follow the steps I have below in that order so you can tell what's causing this.
The first step to do is after the brakes are locked, loosen the nuts that hold the master to the booster and see if they release. If so your push rod is to long, or the pedal is sticking and not returning as it should. (could be the linkage as pitcrew suggested or a bad booster will do this) 
If the brakes are still on, do as Dave suggested and loosen the lines at the master and see if they back off. If they do, replace the master and flush the system.
If none of the above works, crack the bleeder at each wheel, one at a time, and see if that backs that particular brake off. If it does, then the hose is bad. Replace ALL the hoses (and the master too IMO) and flush the system out as it's contaminated.
Good luck and hope you find it! I'm curious to hear what you find.

"Hemilina" My 1973, 5.7 Hemi swapped Javelin
Back to Top
johne View Drop Down
AMC Apprentice
AMC Apprentice


Joined: Aug/04/2012
Location: UK
Status: Offline
Points: 145
Post Options Post Options   Thanks (0) Thanks(0)   Quote johne Quote  Post ReplyReply Direct Link To This Post Posted: Sep/07/2014 at 9:14am
I had a F**D with this problem once - wound up changing the booster.
67 Rebel SST convertible (parts car) RHD
68 Rebel SST convertible RHD
56 Chevy 210 (Long term project)
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19612
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Sep/07/2014 at 10:20am
It could be the booster or the master cylinder.  A bad booster can apply brakes by itself, though that's not the usual failure mode. There are valves in the booster that can fail though, and it can happen. Since everything have been rebuilt or replaced to the wheels, and all four are locking, it has to be something that affects all four wheels. Only three things can do that -- the booster, master cylinder, or brake switch junction block. On the 70 you should have the same junction block with brake failure switch as a drum brake car and a proportioning valve in the rear. I've never known the block to fail in such a manner as you describe. It's almost impossible -- it usually sticks to one side so you have no front or rear brakes, but always have brakes on one end.  It may be possible that it's partially blocked and is affected by heat, but I'd think you'd have marginal braking when it does work if that was the case. If you have a later model combination valve it can fail. Those have the two lines from the MC to the block then three lines to the brakes (one to each front wheel, one to the back). It may be possible for that one to get enough trash in it that it could lock all four brakes, but again, it's very rare and I've never heard of it happening -- usually just one end or the other fails. Therefore, I'd concentrate on the booster and MC. If the MC is a few years old replace it first as it's the cheapest of the two. If that doesn't help look for a new or good used booster.
Frank Swygert
Back to Top
Mopar_guy View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Jun/07/2009
Location: Ohio
Status: Offline
Points: 4805
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mopar_guy Quote  Post ReplyReply Direct Link To This Post Posted: Sep/10/2014 at 3:38pm
So did you try any of things listed? What's the outcome? Question

"Hemilina" My 1973, 5.7 Hemi swapped Javelin
Back to Top
AmeriMan View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/30/2008
Location: Joliet, IL
Status: Offline
Points: 556
Post Options Post Options   Thanks (0) Thanks(0)   Quote AmeriMan Quote  Post ReplyReply Direct Link To This Post Posted: Sep/10/2014 at 4:27pm
BTW it's "brakes" not "breaks". Grammar police. I'll shut up now. ;)
larue390@comcast.net
Back to Top
greasygt III View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: May/27/2014
Location: Florida
Status: Offline
Points: 676
Post Options Post Options   Thanks (0) Thanks(0)   Quote greasygt III Quote  Post ReplyReply Direct Link To This Post Posted: Sep/10/2014 at 4:58pm
    I didn't notice any mention of which type fluid you used. Did you by chance use a synthetic or silicone fluid? I hear it will do some nasty stuff to the seals if you previously had conventional fluid in the system. Just a thought.
83 Spirit GT
79 Ranchero GT 460
Back to Top
 Post Reply Post Reply Page  <123>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.094 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or