Why do my calipers keep sezing

[Drift_86]

Ok like two years ago I had brake fluide coming out of the driver side rear caliper, so I had them replaced with new pads, rotors and calipers. No problem for like 2 years all of the sudden same side caliper seized up on me on the freeway I can see the rotors glowing red. I got home change the rotors and brake pads the caliper seem fine I drove it for like a day. The next day they seized up on me again so I replace the caliper new pads and resurfed the rotors same thing happend. Next I change the brackets, clips, pins, proportion valve from the rear and it happed again. After that I change the brake master cylinder and still doing it! Wtf is going on!? Why do my caliper keep seizing!? I have 96 240sx non abs

[cbcm2435]

did you change your brake lines going from the hard lines to the caliper? if they are the rubber one the inner liner can get damaged and it can actually make your brakes stick on because it will block the fluid from returning back to the reservoir

[KiLLeR2001]

Slide pins. Take them out, clean them up and re-grease them.

[Drift_86]

did you change your brake lines going from the hard lines to the caliper? if they are the rubber one the inner liner can get damaged and it can actually make your brakes stick on because it will block the fluid from returning back to the reservoir

When I replace the proportion valve I checked the rear line if it was being clog by blowing air seemed fine, but I might replace the line with steel line thanks for the info

Slide pins. Take them out, clean them up and re-grease them.
I did two time I even replaced them with new sliding pins

[onehundredoctane]

Moisture in brake fluid will cause the inside of the caliper to corrode I think.

[racepar1]

Maybe you've got a bad e-brake cable. If the e-brake is not releasing completely on that side it would cause the brakes to drag...

[ShadowMan]

Had this same shit happening to me. Replaced the brake master cylinder and all is well. Had it done in under an hour. Just make sure you bench bleed the BMC, then install it or you will be bleeding your brakes forever. For-ev-er.

[SLYDEWAYS 96]

Exactly^
Worked for me

[murda-c]

I replaced 2 rear calipers, replaced the mc, then ended up going with z brakes and havent had a problem since.

[Drift_86]

Moisture in brake fluid will cause the inside of the caliper to corrode I think.
I already replace the caliper and fluid

Maybe you've got a bad e-brake cable. If the e-brake is not releasing completely on that side it would cause the brakes to drag...

That's what I thought but after replacing the the brackets I checked the ebrake if it was all good and I even canceled the ebrake so there's no way it's could be that

[Drift_86]

Had this same shit happening to me. Replaced the brake master cylinder and all is well. Had it done in under an hour. Just make sure you bench bleed the BMC, then install it or you will be bleeding your brakes forever. For-ev-er.

Ok bleed all my brakes and bmc like 10x and my calipers are still seizing????

[ShadowMan]

Ok bleed all my brakes and bmc like 10x and my calipers are still seizing????

No man, more than likely the whole BMC is bad. It's not allowing fluid to return to the resevoir, so when you lift your foot off the brake pedal, the brakes are still applied because the piston is not returning to its nuetral postion, it's getting stuck in the cylinder of the BMC itself. Remove old bmc and replace it with a new one. I was driving my car to a drift clinic and needed one in a hurry so I picked it up from napa for around 80-100 bucks. But it has not happened since I replaced the bmc. I didn't even "need" to rebleed the brake lines. Before I put the new one in, I followed the directions that came with it and bench bled it. It'll say put it in a vice but i just held it in my hands while I used a wooden dowel to pump the BMC by hand. It primes the internals of the unit with brake fluid. Then its just a matter of taking the old one out and putting the new one in. Like I said, under an hour, if you know what your doing.

[racepar1]

If you suspect the master, go drive the car. Get the calipers to "sieze" and crack one of the rear bleeders open. If the master is holding pressure it should squirt a little. It sounds like a possiblity, I would try it...

[Juantwo3]

If you suspect the master, go drive the car. Get the calipers to "sieze" and crack one of the rear bleeders open. If the master is holding pressure it should squirt a little. It sounds like a possiblity, I would try it...


everypost i see of yours , your just full of useful information.

[Drift_86]

No man, more than likely the whole BMC is bad. It's not allowing fluid to return to the resevoir, so when you lift your foot off the brake pedal, the brakes are still applied because the piston is not returning to its nuetral postion, it's getting stuck in the cylinder of the BMC itself. Remove old bmc and replace it with a new one. I was driving my car to a drift clinic and needed one in a hurry so I picked it up from napa for around 80-100 bucks. But it has not happened since I replaced the bmc. I didn't even "need" to rebleed the brake lines. Before I put the new one in, I followed the directions that came with it and bench bled it. It'll say put it in a vice but i just held it in my hands while I used a wooden dowel to pump the BMC by hand. It primes the internals of the unit with brake fluid. Then its just a matter of taking the old one out and putting the new one in. Like I said, under an hour, if you know what your doing.

If you suspect the master, go drive the car. Get the calipers to "sieze" and crack one of the rear bleeders open. If the master is holding pressure it should squirt a little. It sounds like a possiblity, I would try it...

Like I said in the beging I already replace the bmc, caliper, braket, pins, clip, fluid. I did a lot of bleeding I'm getting sick of the whole thing.

[Drift_86]

Dose any one know if the s13 hard brake line fit s14 I'm thinking of just converting to z32 brakes

[om3ga]

If you suspect the master, go drive the car. Get the calipers to "sieze" and crack one of the rear bleeders open. If the master is holding pressure it should squirt a little. It sounds like a possiblity, I would try it...

This is exactly what you need to do. Great information. I would replace that master either way from the sound of things.

[Drift_86]

This is exactly what you need to do. Great information. I would replace that master either way from the sound of things.

I already did I installed a brand new brake master cylinder and still have the same exact problem.

[racepar1]

I already did I installed a brand new brake master cylinder and still have the same exact problem.

I'm not telling you to go out and replace the master. I'm telling you to do some TESTING to figure out what the problem REALLY is. Never replace a part without testing for the issue. It sounds like you've been throwing parts at it without testing for a while now...

As for the hardlines, why would you need to change those? The hardlines are almost certainly NOT the issue and there's no reason to swap them out for Z brakes. You can just blow compressed air through the hardlines to clear them out if you suspect they're plugged. I would reccomend that you inspect the hardlines going to the back of the car for kinks though.

The issue could be in the master, proportioning valve, rubber brake hoses, or maybe the booster. I've seen a toyota truck have a similar issue with a bad brake booster, but that was locking the fronts, which is why I haven't mentioned it.

Don't just change more parts (Z brakes), do the PROPER TESTING to figure out what the problem is first.

[ShadowMan]

What about that one way check valve that's between the booster and the intake? Is that bad? Also, did you replace with a new bmc or used, and it's not unheard of for new parts to be faulty, due to bad manufacturing or improper installation.

[g2ic02]

100 percent rear hose. Generally when someone replaces the calipers they will pinch the hoses to stop fluid from leaking all over. Then the hoses will act as a one way check valve.

[Brian_horne]

i had the same issue. turns out mine were drawing too much vacuum so i adjusted the bolt that goes from the bmc to the backside of the brake pedal. havent had problems since

[sliderite]

rear hoses....replace them.... problem solved.

[Drift_86]

Ok here's an update I tested the bmc how racepar1 said and no fuild came out and I went ahead and replace the the rear brake lines and I'm still having the same problem...

[Drift_86]

Anybody got any idea?

[EvilRB]

Well the easier route would be just replace your hard lines with SS braided lines to eliminate any doubt.
Since everything else is new...Plus you would be ballin' LOL!
I definitly think you have a kink somewhere in the line or a clog that bleeding is not getting out.
So replacing the line or taking it out and clearing it needs to be done.
just what seems to make sence to me... Good Luck!

[racepar1]

Ok here's an update I tested the bmc how racepar1 said and no fuild came out and I went ahead and replace the the rear brake lines and I'm still having the same problem...

If it's not holding hydraulic pressure in the caliper then the hydraulic system is fine. The problem is mechanical somehow. It could be a problem in the caliper itself. If the brake hose was bad, it would hold pressure in the caliper. If the master was the issue, it would hold pressure in the caliper. If the booster was sticking, it would hold pressure in the caliper. When you cracked the bleeder like I said were the brakes still sticking? Or was the wheel free at that point? If the brakes stop sticking within minutes of parking the car it's going to be very hard to test. If the wheel will stay stuck for a bit, it will be easier. I would really like to know how badly the brakes are dragging and how long they stay dragging for after the car is parked.

[Drift_86]

If it's not holding hydraulic pressure in the caliper then the hydraulic system is fine. The problem is mechanical somehow. It could be a problem in the caliper itself. If the brake hose was bad, it would hold pressure in the caliper. If the master was the issue, it would hold pressure in the caliper. If the booster was sticking, it would hold pressure in the caliper. When you cracked the bleeder like I said were the brakes still sticking? Or was the wheel free at that point? If the brakes stop sticking within minutes of parking the car it's going to be very hard to test. If the wheel will stay stuck for a bit, it will be easier. I would really like to know how badly the brakes are dragging and how long they stay dragging for after the car is parked.

Hmm one time before I replaced the bmc the rear wheel would not realease the wheel until I bleed the brake master cylinder, but after replacing the brake master it would never seize up after parking. Now it seems like it would only heat up after getting off the freeway I could smell my brakes and feel the heat coming from my passanger rear brakes and the wheel spines freely even after getting off the freeway. Also I could never feel my brakes are dragging it feels normal when I'm driving all the time.

[Drift_86]

Ok today I think my brakes where dragging after getting off heavy traffic I felt the steering wheel shaking like if I need to balance my wheels but still drive straight... I know it's not my wheels causing the shake I just balance them last month and its not really at high speed

[Dagostino480]

maybe the rotors are warped

[Billiam151]

I know this is an old thread but I am having a similar problem with my brakes. It seems they all lock up at different intervals, I just thought it was my front brakes but they all appear to "drag". Several months ago I replaced the brake booster because I had a very hard pedal, like there was no pressure. fixed the pedal but now I get dragging. replace a couple of calipers thinking it was them but was not, (they were old anyways)lol.. I checked the check valve and it seems to be working fine. I did not set the push rod to anything specific, (the booster I got was used) so I just installed it at the setting it was at.. so now I am at a loss and thinking that I should replace the bmc but I just don't want to just replace it if it not bad. I do not see any lines that are kinked or of issue so some better direction would be helpful. Thanks. this is on a 90 s13.

[Drift_86]

I know this is an old thread but I am having a similar problem with my brakes. It seems they all lock up at different intervals, I just thought it was my front brakes but they all appear to "drag". Several months ago I replaced the brake booster because I had a very hard pedal, like there was no pressure. fixed the pedal but now I get dragging. replace a couple of calipers thinking it was them but was not, (they were old anyways)lol.. I checked the check valve and it seems to be working fine. I did not set the push rod to anything specific, (the booster I got was used) so I just installed it at the setting it was at.. so now I am at a loss and thinking that I should replace the bmc but I just don't want to just replace it if it not bad. I do not see any lines that are kinked or of issue so some better direction would be helpful. Thanks. this is on a 90 s13.

Hmm in my case it was bmc it turned out I had warp rotors in the rear cause I never fix that after replacing my bmc... If I was in your place I would go ahead and replace it bleed out all you're brake fluid.