brakes locking up.
Thread Starter
|
New User
Joined: Apr 2005
Posts: 24
Likes: 0
brakes locking up.
I have a 68 ford f100 manual brakes. I have a problem with the brakes slowly locking up. I have replaced all the wheel cylinders, tried 3 master cylinders, but it does the same thing. You drive it for awhile and slowly the brake pedal comes to the top and you have to release the pressure at the master cylinder by loosening the brake lines. I've never had this happen to me before. Can anyone out there give me an idea of what to do to remedy this problem?
Senior User
Joined: Feb 2005
Posts: 414
Likes: 0
From: Southwestern Pa.
If it was 4 wheel with 1 flex line i would have said that was the problem. If there are two hoses they both could be bad. Do you let the pressure off at the master cylinder or at the wheel cylinders?
Mountain Pass
Joined: Jul 2004
Posts: 229
Likes: 0
From: San Diego, CA
On some models the rod is adjustable and if you have over adjusted it, it will do the samething. Midas done that once on a truck that I had.
Trending Topics
Senior User
Joined: Feb 2005
Posts: 414
Likes: 0
From: Southwestern Pa.
If you can release the pressure at the lines at the mastercylinder that would indicate that the hoses and lines are ok. Unbolt the mastercylinder from the firewall (don't undo the brake lines) and push it against the firewall. You should not feel any pressure while pushing it in. If you do then the rod is out of adjustment as Briank said or the replacement master is different. Good luck and let us know.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
New User
Joined: Apr 2005
Posts: 24
Likes: 0
This one has no adjustment. Everything was ok except the old mc was holding pressure. So I replaced the mc. Thats when the trouble started. I thought it was in the wheel cylinders,, so I replace them also. I have tried 3 different mc on it. I did notice the old wheel cylinders they were full of crude,so I replaced them and i thought I'd clean eveything out good. I just don't know where the problem could be.
Thread Starter
|
New User
Joined: Apr 2005
Posts: 24
Likes: 0
The strange thing is that once you release the pressure you can drive it for awhile before it does it again. It takes 5 to 10 stops before it starts locking up. It won't totally lock up, but I can tell it is not totally releasing.
!["Beemer Nut"'s Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%23bc5285' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>"</text></svg>)
Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
Have someone "slowly" apply the brakes when you have a release problem while looking into the master cylinder reservoir to see if fluid escapes before the piston closes off the ports. This would be for proper rod length. Old flexible lines can swell with age, pass fluid under pressure but constrict down and not let fluid return. Even if you get one end repaired how's the wheel cylinders, springs and hoses at the other end?
.....=o&o>.....
.....=o&o>.....
Freshman User
Joined: Sep 2003
Posts: 30
Likes: 0
From: burbank
hi fender72 and FSC. do u mean the brake pedal doesnt brake on the first step, but when u press it again it vibrates. like gettin a metal to metal grinding feeling???i was drivin today 6/6/05 n i almost didnt stop.like everytime i tried stopping it jus barely clamped on the rotors??? pls email me back because this is scarin the hell out of me... ive already had it done by a shop. do u also hear a weird howling sound that u can only hear intermittently??? i need help bad...email me pls at lilnbbs@yahoo.com or if not there... jus here
Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
Sounds like the pistons in the master cylinder are closing off the return fluid ports as you stated you can't move the pedal when brakes drag. Did you check the return ports as I posted above?
.....=o&o>.....
.....=o&o>.....