My 1982 FJ40 brakes lockup after driving for about a mile. I have rebuilt the ebrake parts in the rear, new shoes and brake parts, replaced both calipers and rotors, all of the rubber brake hoses. I have purged all of the brake fluid and still locks up after about a mile. Should i replace the master cylinder?
FJ40 brakes, hydraulic lockup (1 Viewer)
- Thread starter 447xpro
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JohnnyC
Long ago TLCA# 2231
It's your pedal/rod adjustment
What he said. ^^^^
The new pads are exacerbating the problem. If you have a laser thermometer, check the temp of the calipers when they lock up. I'm guessing they're very hot. The brakes are dragging, heating the fluid. It is expanding and pushing the pads into the rotors.
The new pads are exacerbating the problem. If you have a laser thermometer, check the temp of the calipers when they lock up. I'm guessing they're very hot. The brakes are dragging, heating the fluid. It is expanding and pushing the pads into the rotors.
- Thread starter
- #4
I will check that , thanks
447xpro
Did this resolve your problem? I had my 82 recently towed, then the passenger side rear cylinder started leaking. Both rear cylinders were replaced, rear drums resurfaced, and brake fluid was flushed by Firestone (don't judge, I'm short on time to wrench these days). They even replaced the brake hoses in the front and rear. I drive for about 10 minutes and the brakes get more and more stiff as I drive. It gets to the point where the engine almost dies because it is pulling so hard against the brakes.
I just want to drive my baby without the brakes locking up.
If this was the issue, how hard was it to resolve? Any tips to expedite the process?
Did this resolve your problem? I had my 82 recently towed, then the passenger side rear cylinder started leaking. Both rear cylinders were replaced, rear drums resurfaced, and brake fluid was flushed by Firestone (don't judge, I'm short on time to wrench these days). They even replaced the brake hoses in the front and rear. I drive for about 10 minutes and the brakes get more and more stiff as I drive. It gets to the point where the engine almost dies because it is pulling so hard against the brakes.
I just want to drive my baby without the brakes locking up.
If this was the issue, how hard was it to resolve? Any tips to expedite the process?
having the rod to tight from the pedal to the booster will also cause this problem you can set it to specs or loosen it a turn at a time until they stop locking up .another problem is the return hole for the fluid could be plugged in the master not allowing fluid back into the resivour .get under the dash and see if there is any play in the brake rod when you press the pedal .can do this by hand as you watch if no play adjust as needed
A lot of people, including myself, want to throw on a new part and get going ASAP. What often gets overlooked is ensuring adjustments to spec. As mentioned above, there are several adjustments that need to be in spec:
Click on my Sig to get to the store page. Downloads on the RHS of the page. Look in the Appendix section of the brake booster installation guide.
- Brake pedal adjustment
- Booster rod to Master Cylinder
- Drum brake wheel cylinder adjustment (if applicable)
Click on my Sig to get to the store page. Downloads on the RHS of the page. Look in the Appendix section of the brake booster installation guide.
Mahalo! I'll give these a shot tomorrow. Keeping my fingers crossed for success! I'm ready to start driving my cruiser again.
Thanks for the clear instructions and advice.
I had the same problem with mine. rebuilt all even a new master. that created a new problem of no fluid to the rears. I wish I had seen this earlier nutted this out myself wondering why it was like that. Now I know I will check the clearence
Well the crew at Firestone say the pedal rod and booster rods are set to the proper clearance. They said they removed the master cylinder and noticed a lot of crud/rust in between the MC and brake booster. Fortunately, they didn't charge me a $0.01.
I'm looking at RockAuto for a master cylinder and brake booster. A buddy says rebuilding the brake booster will be cheaper and just as effective.
My thoughts are this is all the original, 33 year old, parts that I should just replace both and move on.
Open for comments in 3...2...1...
I'm looking at RockAuto for a master cylinder and brake booster. A buddy says rebuilding the brake booster will be cheaper and just as effective.
My thoughts are this is all the original, 33 year old, parts that I should just replace both and move on.
Open for comments in 3...2...1...
Your truck is a 1982, and you want a new booster?
I think I want a new booster. I'm on the fence about it because I just don't know enough in that area. That's why I'm asking the IH8mud team.
If a new master cylinder will do the job, I'll stop at that.
If a new master cylinder will do the job, I'll stop at that.
Booster to master cylinder rod adjustment is super important ,it's a pain to adjust but nine times out of ten thats the problem.
But can that adjustment fall out of whack for no reason?
But there were no adjustments to the brakes. Nothing. Just a tow job to the mechanic shop.
The master cylinder and lock nut were untouched.
The master cylinder and lock nut were untouched.
I guess that there is no problem then.
If you want to confirm that your master cylinder is building up pressure, just crack the nut on the hydraulic lines to your MC and see if there is a spurt of fluid and the problem goes away.
I like reading Pin_Head's postings. He knows stuff.
He sure does. I've replaced the brake check valve and brake pedal play is back to what it used to be. I'll take it for a test drive later.
I broke a good portion of the old check valve during the removal, but when I blowed thru it, it wasn't quite stuck, but it took some force to get the air thru.
I broke a good portion of the old check valve during the removal, but when I blowed thru it, it wasn't quite stuck, but it took some force to get the air thru.
