brake locked

i have another problem....on my 98 camaro, me and my cousin changed the brakes on it, they are 4 wheel disc incase anyone doesnt know.... after a few days of having the new brakes on the drivers rear brake locked and thats the only one that has done that. the ebrake isnt set. after a couple minutes of driving the rotors are way too hot to touch. my question is what would cause this and/or how do you adjust them and how do i need to adjust them? thanks!!

If they are locking with pressure being applied , first check the hose condition on that side and then replace the caliper if the hose appears to be fine but it is still locking.

the brake is locked without pressure....ive got the car up in the air and i put it in neutral and tried turning the driver rear wheel and its all i can do to turn it....its rubbing the whole time and moves very slow...thanks!

it didnt start doing this until after we changed the brakes....this morning we bled the brakes and everything seemed okay and i drove the car for a couple of miles and everything seemed okay so i came back home and parked the car and left this evening and after about 5 miles it started making this horrible noise again so i stopped and the rotors were extremely hot and the brake was locking again....i wonder if the brake line has collapsed on the inside or if the caliper is bad? what else could cause this? thanks!

You bottomed the piston when you installed the new pads?

everything seemed okay on it when we changed it....everything was fine before except the pads were wore really bad. I replaced the brake line this morning and thats not the problem so i guess im gonna go change the caliper....hope that works!!

update: i went out and bled the brakes and its still rubbing all the time....so we bled all the brakes and as long as the car is off the brake pedal seems to hold good pressure and as soon as i start the car the pedal goes straight to the floorboard. i pumped up the brakes and they hold pressure for about 2 seconds then it goes back to the floorboard. there are no leaks in the lines and there is plenty of fluid. when the car is started and you pump up the brakes and hold it and it goes to the floorboard the RPM's start jumping up and down then after a few seconds settles down to where the RPM's should be. any ideas on what to check next? thanks!!

booster check valve, first guess

thanks...this might sound stupid...but how do you check that?

But it could just be that since the pedal travel is so much for a serious air pocket or leak.

try and blow through it, air should only pass one way.

there isnt an air pocket...when we bled them no air came out only fluid and there are no leaks...thanks!

try and blow through it, air should only pass one way.

cool thanks!

sounds like the caliper seized. take it back off, and use a metal file to rub down the contact patch between the two parts, then apply some silicone to the surfaces and put it back together again. you dont need to go nuts with the metal file, but theres probly some corrosion or rust there that would cause the calipers to bind.

Just a longshot, but is it possible you guys crimped both rear brake hoses somehow? Because brake hoses are actually made up of a hose inside a hose. when the inner lining splits open once you press the brake, it puts pressure at the wheel piston, but when you let off the brake, the internal break will seal off, leaving fluid from the split part of the line to the wheel piston.

This would explain why your pedal sinks after a few seconds: you are pumping and pumping more fluid into the line(which is flowing out of the inner hose but not being let out by the outter hoses) until the hose(s) are full which results in your low pedal until you pump it.

And a way to check the vacuum booster is this:
1. with the car OFF, pump up the brake pedal continuously until it gets really hard
2. hold pressure on the pedal
3. start the car
4. the pedal should go down now that manifold vacuum is present

if the pedal never gets hard or doesn't go down like it should, then look at the booster.

sounds like the caliper seized. take it back off, and use a metal file to rub down the contact patch between the two parts, then apply some silicone to the surfaces and put it back together again. you dont need to go nuts with the metal file, but theres probly some corrosion or rust there that would cause the calipers to bind.
Rather than trying to use a file possibly causing a pressure issue with the caliper piston. I would think it would be a much safer bet to just replace the caliper assembly with a fresh unit or even a used unproblematic unit.

Just a longshot, but is it possible you guys crimped both rear brake hoses somehow? Because brake hoses are actually made up of a hose inside a hose. when the inner lining splits open once you press the brake, it puts pressure at the wheel piston, but when you let off the brake, the internal break will seal off, leaving fluid from the split part of the line to the wheel piston.

This would explain why your pedal sinks after a few seconds: you are pumping and pumping more fluid into the line(which is flowing out of the inner hose but not being let out by the outter hoses) until the hose(s) are full which results in your low pedal until you pump it.

And a way to check the vacuum booster is this:
1. with the car OFF, pump up the brake pedal continuously until it gets really hard
2. hold pressure on the pedal
3. start the car
4. the pedal should go down now that manifold vacuum is present

if the pedal never gets hard or doesn't go down like it should, then look at the booster.

i know the brake lines are good cos i just put new ones on today....i will go check the booster now...thanks!!

i tried those steps checking the brake booster and it held real good pressure until i started the car and when i started it the pedal went almost all the way to the floorboard, past where it should and as soon as i let off the brake the rpms start jumping like crazy...could that be the booster? thanks again for the help everyone!!

Rather than trying to use a file possibly causing a pressure issue with the caliper piston. I would think it would be a much safer bet to just replace the caliper assembly with a fresh unit or even a used unproblematic unit.

not dangerous at all, its a common repair in shops. i did it all the time.

i tried what 89 said and its still grabbing so we replaced the caliper brand new and its still grabbing all the time...it doesnt lock but it still is grabbing the whole time and the pedal seems to hold pressure now....any ideas?

sorry bud, there's gotta be something basic htat didn't get done right in the original swap.

you opened the master cylinder resivour and siphoned a little fluid out AND left it open before resetting the calipers right?

how did you reset the rears?

you opened the master cylinder resivour and siphoned a little fluid out AND left it open before resetting the calipers right?

I didnt know you had to...we changed them in my cousins 99 and they turned out okay....i will go try that next...thanks!!

Well the booster is supposed to go to the floor when you start the car(provided you have pumped it up and are holding pressure on it with your foot).

I'd say operator error :lol2:

Did you bleed the brakes correctly?

Camaros use a front/rear split system, so you need to bleed both of the rear brakes before you move to the front.

What is your definition of grabbing? There is usually some resistance of the pad on the rotor, you should be able to move the rotor freely with your fingers by the studs.

Also, if they are grabbing in one spot... it is imperitive that you torque all the wheel's bolts down evenly. I believe it is 100ft-lbs of torque for the lug nuts.

i know the pedal goes down when you start the car....but it looses all resistance and goes straight to the floorboard...yeah im certain we have bled the brakes correctly...we have bled them atleast 5 times...yep we started with the rear brakes first, i didnt know that but yep we did...i know there is some resistance but in neutral its all i can do to turn it and the brakes are grabbing so hard that when i drive and barely press the brakes the wheel actually locks up completley and skids, sounds like a rod knocking when it does it...without using the brakes i can drive the car for a mile and a half or so and when i get back that one rotor is unbelievably hot and the others arent and smoke pours out...its not grabbing in one spot...its all the time....thanks!!

Stupid question... You're using DOT 3 correct? And brand new fluid? That has never been open for more than a few minutes while bleeding? Because water/moisture in the lines would cause the brakes to function normally until they heat up a bit, which will heat the water to steam, which expands, holding the brakes on until it cools off.

My last guess would be the parking brake adjusted improperly, or out of spec.

I'm looking at some technical service bulletins on LS1 Camaros about the brakes and stuff... something to look out for:

-When you change the pads/rotors, when you top off the master cylinder, make sure it is at the "MAX" line, because being overfilled will make the brakes act up.

I'll read up on most of the stuff and post up what I find...

AH-HA!!!

http://img.photobucket.com/albums/v294/flatlander757/Car%20Related/98brakefix.jpg

http://img.photobucket.com/albums/v294/flatlander757/Car%20Related/parkingbrakeadjust.jpg

:smile:

tyvm flatlander!! i knew there was a problem with the e brake for a long time...it hasnt worked in months...im going to check that out in the morning....that makes a lot of sense and i hadnt thought of it....thanks again!!

N/p... but next time mention that the ebrake hasn't worked in months since it kinda deals with the rear brakes :wink:

lol i forgot about it....since i never use it

*smacks forhead*

DOH!!!!!

this is why I say mention everything wrong, CLEARLY, no matter how insugnificant it may seem, it may be the key.

But, since you didn't open the master when resetting the pistons I'm a little concerned there. Plus you did use the twist in adapter to reset the rears right and jamb them back in with c-clamp wondering why it's so hard the whole way down?

Not insulting, I've seen it done.