Brake Calipar Sticking- I think

[gearshift]

I replaced my passenger side front brake calipar, because it was stuck on close and grinded the brake pads down to the medal. I replaced the brake calipar with brand new pads (the other pads on the car are 1.5 years old). But, when am driving, I get the heavy brake pad smell coming from the side that was replaced, and the rotor and surrounding area is three times as hot as all the other rotors.

I ended up also replacing the master cylindar and power brake booster. Also, the wheel with the new calipar and pads does not spin as freely as the drivers side. There is no leaking, but I believe the calipar is not opening up all the way again.

Anyone with similar experience or advise would be most welcome.

Thanks

 

[c4cruiser]

It sounds like there may be a restriction in the line leading to that caliper and not allowing the pressure from braking to be released completely. There could be some particles in the fluid that has caused a restriction.

If you haven't already done a fliud flush, I would do that and watch the rate of flow of fluid from that caliper to see if it is the same as from the other calipers. Check the hard line from the ABS to that wheel for any damage like kinks or pinches. Are the hoses the original ones? You may want to replace them.

To really do a complete flush including the ABS, you will have to have a shop hook up a Tech-1 with the brake module in order to activate the ABS pump to purge the old fluid out of the ABS module. Otherwise a flush will only clear fluid from the hard lines and calipers. Doing a number of "panic" stops will activate the ABS and functionally do the same thing, but then you have the old fluid from the ABS in with the new fluid.

 

[gearshift]

Will do a flush and replace the hoses.

Yea, I checked the wheel today and it is really sticking. I'll try the complete flush, including ABS and replace the brake hoses as they are the originals.

Thank you.

 

[jmccloud]

"Sticking" calipers

I've had at least 3 cars and one truck that did this (fortunately not my Corvette). Even accused my wife of driving with her foot on the brake (she wasn't). Resided in the doghouse for days.
In every case it was a bad flexible brake hose connected to the caliper. Evidently the failure mode is that the hose collapses. The brake master cylinder has adequate pressure to spread the hose but when pedal pressure is released, the hose collapses and acts like a check valve and holds the brake on. Stink. Smoke sometimes. Lots of pad dirt. Warped rotors.
The real diagnostic is to get the wheel safely off the ground, apply the brake with the engine running (to get power assist), release the brake and check for free wheel spin. (turn off the engine) If the wheel won't spin freely, open the bleed valve to release fluid pressure to the caliper. If it spins freely then, the hose is shot.
Hope this helps.

 

[Zixxer]

Wow, can I relate to your problems.....just search for my previous posts.

I had a front left wheel showing a lot of brake dust and clearly overheating after a complete replace of rotors, pads, hoses, and calipers. I even replaced the ABS unit which turned out to waste of time but certainly a learning experience. The ABS replace didn't fix my problem so I looked at my rebuilt calipers and opted to replace them again with a set of Grand Sport calipers because everything I read says that the o-rings or seals are responsible for retracting the pistons and allowing free spinning wheels. I should have looked sooner but I didn't think new calipers could be at fault. Anyways, turns out the calipers I replaced where bad and the new GS calipers worked great. I had to re-turn one rotor and now I have even brake wear on the car after the GS calipers were installed. The car did not pull to the left or pulse when brakes applied. This was a pain to solve and even the original mechanics were puzzled. I solved it myself and feel pretty good about taking the time to learn the details of all the components.

 

[RonJ]

When I hear of a problem like yours, first thing that comes to mind is that the slides for the caliper are hanging up. When you changed the pads, did you take the pins right out, clean them and apply fresh lubricant? A simple thing, but super important. Make sure the caliper isn't hanging up, it has to be free!!

Secondly, when the caliper is off it's mount, be sure the piston will move back fairly easily if you put a c-clamp to them. You have to push them back to get the new pads in anyways, just notice how hard it is to force them back. If they are hanging up, you will smoke any new pads you instal.

It's possible that flex lines have collapsed or steel lines are "dented" etc., but always look for and rule out the obvious and the simple first!!

Hope this helps ..... Ron ...

 

[Zixxer]

I thought the same thing....bought new pins and polished the slides on the calipers and the braces...they were a little rough but not enough to cause problems.....no change, the new calipers were the fix but certainly an area to look at. The manual says to replace those pins after each brake job but I know mine were probably original as one side was worn flat.

 

[gearshift]

Brake Calipar

1. I will first replace the hoses. They may have collapsed.
2. Then I will get a fluid flush, including the Tech 1 ABS system flush
3. The pads were already installed on the Calipars, so I did nothing to it, except install the calipar and hooked up the hose.

I am confused on the pins? The only pins were the one long pin that hooked the calipar to the rotar mount. Is this the pin that needs to be lubercated? Because it was not and I hammered it in.

Thanks for the replies.

 

[Zixxer]

Yep, the long pin that slides into the bottom with the c clip. It should have gone in with just a little effort if the caliper was placed into the brace correctly. You might not have pushed up and into the brace when placing the caliper. The pin should be easy to remove and reinstall, some effort but not a lot.

 

[VetNutJim]

Because it was not and I hammered it in.

There's a big hint in this statement as to the cause of the original problem.

 

[Vettelt193]

when you put the brakes on, with fresh pads (after using a c-clamp or other to push the pistons all the way in) the brake caliper will actually be a little loose, and should move a bit from side to side (not front to back) this is because they are free floating calipers. That is also a good test to ensure that you installed everything correctly.... Try taking things apart and putting them back together before you waste your money on new parts. (although, a fluid flush is never a bad idea)

 

[gearshift]

Brake Calipar Sticking

Thanks for all the feedback. After I installed the new hoses, (greesed the pin- not hammered I still have the sticking problem. Here is what I have discovered. The Modulator valve is shot. They shop that found this to be the problem wants $1700 for a new one. The unit has to be replaced when the valve goes out.

So, my final question...does anyone know of a better place to get a modulator valve than NAPA?

Thanks

 

[VetNutJim]

Thanks for all the feedback. After I installed the new hoses, (greesed the pin- not hammered I still have the sticking problem. Here is what I have discovered. The Modulator valve is shot. They shop that found this to be the problem wants $1700 for a new one. The unit has to be replaced when the valve goes out.

So, my final question...does anyone know of a better place to get a modulator valve than NAPA?

Thanks

I don't know everything about this but I don't think there is a 'modulator valve' on your brake system.
And if there is, 1700 bux is outrageous for it.
The whole ABS Control System won't cost that.
Find another mech.

 

[jmccloud]

Modulator valve

Autozone lists a "Control Module" for $386 and a "Hydraulic Unit" for $504