Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1856536
06/25/15 12:21 PM
06/25/15 12:21 PM
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Joined: Jul 2007
Posts: 11,836 Florida
mopar346
Let me tell ya about fat chicks!
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Let me tell ya about fat chicks!
Joined: Jul 2007
Posts: 11,836
Florida
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Sounds like your brake lines are heating up and the fluid is expanding. If you replaced the brake lines check the routing to make sure they aren't near the exhaust anywhere. Another thing I would verify is if it is all 4, just front, just rear or just a wheel, helps isolate which line(s) to look at. You also might check to see if the underhood heat is too high from something like headers or the engine getting too hot.
Good luck.
Careful, your character's showing!
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Re: brakes get tight after a few miles of driving?
[Re: TJP]
#1856576
06/25/15 01:09 PM
06/25/15 01:09 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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It happened to me. New master cylinder installed, truck drove well in the morning. By afternoon when the temperature was up, the brakes were locked. I had to bleed out some fluid to be able to drive home. Adjusting the pushrod made it all OK. R.
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Re: brakes get tight after a few miles of driving?
[Re: skicker]
#1856597
06/25/15 01:26 PM
06/25/15 01:26 PM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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with a helper you might crack a bleeder to see if it is a psi prob or a piston/square seal (mechanical) caliper problem. If its psi then tighten the bleeder back up & being carefull not to intro air into the system & crack a line right at the MC next to the firewall (for the front discs) & see if that relaxes it which if so points to an internal MC prob as opposed to something downstream. Holler how it turns out. k.i.s.s. I'm thinking just bad calipers not retracting enough
live every 24 hour block of time like it's your last day on earth
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Re: brakes get tight after a few miles of driving?
[Re: TJP]
#1856689
06/25/15 03:13 PM
06/25/15 03:13 PM
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Joined: Jan 2003
Posts: 25,784 Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,784
Rio Linda, CA
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Sounds like the master cylinder is not returning all the way, Check the pushrod to piston clearance. should be .030 to .060 X3 Adjustable pushrod?
The INTERNET, the MISinformation superhighway
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857034
06/25/15 09:51 PM
06/25/15 09:51 PM
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Joined: Jul 2007
Posts: 11,836 Florida
mopar346
Let me tell ya about fat chicks!
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Let me tell ya about fat chicks!
Joined: Jul 2007
Posts: 11,836
Florida
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Why would the push rod length matter with heat? It shouldn't change. Not arguing just trying to understand.
Careful, your character's showing!
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857036
06/25/15 09:55 PM
06/25/15 09:55 PM
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Joined: Mar 2007
Posts: 532 Marion, Ohio USA
kab69440
mopar
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mopar
Joined: Mar 2007
Posts: 532
Marion, Ohio USA
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Your hoses are shot. Replace them.
Just because you're paranoid, it doesn't mean they are not out to get you.
WANT TO BUY- Looking for a CD by 'The Sub-Mersians' entitled "Raw Love Songs From my Garage To Your Bedroom". Also, any of the various surf-revival compilation albums this band has contributed to.
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857063
06/25/15 10:24 PM
06/25/15 10:24 PM
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Joined: Oct 2007
Posts: 3,884 Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,884
Oregon
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From what I understand, as the fluid heats up, it has to expand somewhere. That somewhere is in the master cylinder, pushing back towards the pushrod. So having just a tiny bit of clearance there is enough to keep it from locking up.
If you ever find yourself in a fair fight, your tactics suck.
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857072
06/25/15 10:38 PM
06/25/15 10:38 PM
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Joined: Jul 2007
Posts: 11,836 Florida
mopar346
Let me tell ya about fat chicks!
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Let me tell ya about fat chicks!
Joined: Jul 2007
Posts: 11,836
Florida
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I believe the piston can only move back to the stop/lock, correct? If the rod was pushing on the piston it would hold pressure cold or hot. I agree that fluid expands with heat. Just trying to wrap my head around it. Strangely enough my new to me RT was doing the same thing, I had to introduce some air into the system to be able to drive it home. I'll fix it when I get it here. I cant say that any of my other old cars experience anything like the pedal changing when they get warm. I built a Vette years ago that I had the issue with and it was an issue with the lines being too close, not to mention I have seen it a number of times professionally.
Careful, your character's showing!
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857413
06/26/15 02:34 PM
06/26/15 02:34 PM
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Joined: Feb 2003
Posts: 18,582 Rust Belt, SW PA
Silver70
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 18,582
Rust Belt, SW PA
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What master cylinder are you using? I know I have modified some drum style for discs over the years... if it's a drum style, there's a valve that needs removed. Drum keep pressure and need the stop valve, while discs need to let the pressure off.
68 Road Runner, 69 Belvedere, 71 Challenger Vert 340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z 66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857452
06/26/15 03:40 PM
06/26/15 03:40 PM
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Joined: Jul 2007
Posts: 11,836 Florida
mopar346
Let me tell ya about fat chicks!
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Let me tell ya about fat chicks!
Joined: Jul 2007
Posts: 11,836
Florida
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OK dogdays I can wrap my head around that, the rod has the piston in far enough to cover the hole, no consequence when the system is cold, even though it is holding slight pressure to the brakes. When it heats it would normally allow the fluid to push back into the master but since the piston is in the way it cant cause the pressure to apply the brakes. I've never looked at it that way but I could see it.
Silver70, my new RT is stock drums with a replacement but original style master. Since you are saying it essentially has a one way check valve would the rod still possibly be effecting my situation? The car is in PA and I'm in FL until Carlisle so I cant check it. I bought the car assembled so I cant say what the rod clearance was.
Thanks for the patience guys this has been good information. Much better when explained verse just it's the rod.
Careful, your character's showing!
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Re: brakes get tight after a few miles of driving?
[Re: dirt]
#1857746
06/26/15 10:39 PM
06/26/15 10:39 PM
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Joined: Jul 2007
Posts: 11,836 Florida
mopar346
Let me tell ya about fat chicks!
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Let me tell ya about fat chicks!
Joined: Jul 2007
Posts: 11,836
Florida
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What does it do if you break the line to the front brakes loose at the master? If it releases then the pressure is being held at the master. Breaking it loose at the caliper only eliminates the caliper.
Careful, your character's showing!
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