Brakes locking up
Brakes locking up
I have a couple of questions about this subject. My front brakes are locking up on my M/T 240sx. I have the neutral safety switch-have not changed it yet, and just got finished changing the clutch ignition switch. Could this be part of the problem, or could it be the brake booster. When we first got it cranked, (had to get a new battery) it moved maybe 2 ft, and then the front locked up. They were not hot, due to the fact that it had not moved but a couple of feet. Do I need to try the switch first, or could it be the brake booster? / master cyinder. Checked the lines for the front (only ones doing this) and found no kinks or leaks from either them, or the booster & master cylinder. Please help!!!!!!!!!
Re: Brakes locking up
PS. Already ordered new calipers, but I am not totally convinced this is the problem. Had similar issues with another vehicle, and it was the Master Cylinder.
Re: Brakes locking up
Also the brake pedal is HARD AS A ROCK!! Cannot move it at all.
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Hijacker
- Posts: 14373
- Joined: Wed Aug 13, 2003 4:57 am
- Car: '92 240sx Convertible
'94 F-150 - Location: Fredericksburg, VA
Re: Brakes locking up
The electronics won't make a difference unless the car has ABS. And even then, it would only be sensors pertaining to the ABS.
Swap out the calipers. They could be locked. A failed MC in my experience tends to reduce pedal pressure, resulting in a no-stop situation. Are you positive that the fronts are locked and you're not pushing against a locked trans or rear diff?
Swap out the calipers. They could be locked. A failed MC in my experience tends to reduce pedal pressure, resulting in a no-stop situation. Are you positive that the fronts are locked and you're not pushing against a locked trans or rear diff?
Re: Brakes locking up
Pretty sure it is not a locked trans or differential. If the diff was locked up, wouldn't that make the rear lock up and not the front? Trans only has maybe 40,000 on it, so I really do not believe that is it. It will shift (in place no problem) and it acts like it wants to go. The drivers side moved a little more than pass, but pretty much both would not move. The brake pedal has extreme pressure on it and it will not move whether cranked or not. We should get the calipers on Tues to install, I was wondering about the MC (I thought the same as you, as far as experience), and that is why I was also wondering about the booster.
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mechanicalmoron
- Posts: 790
- Joined: Fri Apr 29, 2011 1:04 am
Re: Brakes locking up
Sounds like SOMETHING'S seized.
You could try bleeding the fronts, and seeing if you can manually move the pistons with a clamp/compressor tool/whatever. Have you checked that when it's lifted, you can't spin the front wheels? Or maybe it's got super warped rotors or something, and something is binding or wedged?
It seems unlikely that it's the booster, and it's impossible that it's the neutral safety switch, that's related to the starter.
If the pedal doesn't soften over time with the motor off, I don't really see any way it could be the booster.
See what wheels you can spin when it's raised with the parking brake off, whichever ones won't turn, remove, and start tinkering.
You could try bleeding the fronts, and seeing if you can manually move the pistons with a clamp/compressor tool/whatever. Have you checked that when it's lifted, you can't spin the front wheels? Or maybe it's got super warped rotors or something, and something is binding or wedged?
It seems unlikely that it's the booster, and it's impossible that it's the neutral safety switch, that's related to the starter.
If the pedal doesn't soften over time with the motor off, I don't really see any way it could be the booster.
See what wheels you can spin when it's raised with the parking brake off, whichever ones won't turn, remove, and start tinkering.
Re: Brakes locking up
We have the car up on a jack right now. Once my husband took off the caliper on the passenger side, the brake pressure as fine. It looked as if the calipers were stuck, so hopefully we will get them replaced soon and that will be the problem. Thanks for everyones input and help so far!! Will post more once this is taken care of! 