Caliper sticking issue.

[MikeInCtown]

Forget about the rubber flex lines. They have nothing to do with your problem. You have air in your lines. You have to re-bleed the system. Brake fluid does not compress nor build pressure. Bleed all your calipers not just the front.

 

A problem in the system could very well cause fluid pressure to build as was described. Remember that the fluid forces the caliper piston out under pressure and when you release the pedal, that pressure is supposed to be relieved. It just doesn't magically disappear. Also, if you read the very first post, you would see that the problem happened BEFORE he replaced the calipers, so it is unlikely that any air was in the system at that time.

[brucelimerick]

Yes, you are right MickeyZ. I had forgotten the original post.

Here is a pretty good explanation of the probable part of the brake system causing the problem.

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/master-brake.htm

When the pedal is up and not pushed the whole brake system should be at atmospheric pressure. ie no pressure anywhere in the system. The only way to generate pressure is if something is blocked and the pressure from pressing the brake pedal can't be released when it is released. Pay attention to page 3, the proportioning valve and the metering valve. I believe the differential pressure switch on GM trucks is on the master cylinder. Don't quote me on that. There is a possibility it is the master cylinder but it doesn't sound like it. If it was the brake light should be on on the dash. That would be indicating a leak in the system. Doesn't sound like the problem because both front brakes are getting hot. If there was a leak only one would be getting hot. This could also happen if the master cylinder was having problems and one of the pistons was stuck. I would say your problem is in the combo valve. I don't remember one on my 2001 when I redid the brake lines. The 2 lines coming out of the master went to the ABS unit which means these valves or their function is internal to your ABS system. My 2001 has rotors on all 4 wheels. GM went back to drums on the rear a year or 2 later. They may have added the combo valve back into the system. I would hope so for your sake as the ABS unit is quite expensive. The ABS does have it's own idiot light on the dash but I'm not sure what events make it turn on.

[pm26]

What is scary is that people who have no clue how to work on brakes often attempt to do the work in order to save a few bucks. The other day I saw a young guy working on his truck front brakes. He removed the entire calipers from the truck in order to replace the brake pads. When I asked him if he realized that the disconnected brake lines are now full of air and will have to be bled, he looked at me with a vacant expression, as he had no idea what a hydraulic brake system was or how it worked.

 

I also had a friend who had someone work on his brakes in a shop and someone put in the brake pads inside out into his calipers sot that the metal parts were pressed against the rotors. His brakes made this horrible grinding noise and two days later his rotors had 1/4 inch deep grooves in them.

[gmtech4]

What is scary is that people who have no clue how to work on brakes often attempt to do the work in order to save a few bucks. The other day I saw a young guy working on his truck front brakes. He removed the entire calipers from the truck in order to replace the brake pads. When I asked him if he realized that the disconnected brake lines are now full of air and will have to be bled, he looked at me with a vacant expression, as he had no idea what a hydraulic brake system was or how it worked.

 

I also had a friend who had someone work on his brakes in a shop and someone put in the brake pads inside out into his calipers sot that the metal parts were pressed against the rotors. His brakes made this horrible grinding noise and two days later his rotors had 1/4 inch deep grooves in them.

i try to say this same thing a million times but i get yelled at because (people want to fix it themselves ) speech,, i agree 100 % ,,once i saw the word "hammer" in the opening complaint i shuddered ,,,,

 

good on ya pal for telling like many of us want to say !!!

[jblakeney]

I ran into a trailblazer a few years ago, that had the ABS pump running. It was barely noticeable audibly. It too had a stuck brake caliper. Also, had drove the owner nuts, he had replaced all 4 calipers.

 

He had it towed to my shop. Upon initial viewing of the truck on my lift. I noted left and right calipers were reversed on front and rear, bleeder screws go atop the caliper not on the bottom. I had everything in working condition and sliding freely. Pressed the brakes without the truck running never could get it to stick. For some reason I cranked the truck on the lift and had somebody in the cab pressing the brakes for me. I noticed I felt a small vibration on the lines leading from the ABS, continued to feel around and found the pump was running. Pulled the fuse it quit put it back the brakes stuck, pulled it they worked. After several rounds of that, I decided the module must be the cause. I don't remember the complete diagnostics, as its been a few years. I do remember the pump was bad, and possibly the whole ABS module and hydraulic body. I DO REMEMBER THE brake fluid was BLACK with a rust tint. I blamed the rust as the culprit.

 

As far as the 2 rubber hose looking pieces (obo 1inch long) on each front caliper. They stick inside the caliper pin bore, cushioning the caliper pin. They should be pushed fully into the caliper pin bore. Then the rubber boot installed. Then the pin lubricated and installed on the vehicle.

Edited January 2, 2014 by USMdude

[Diecutter]

I have a 2001 silverado and the exact same thing is happening with my truck, brakes are dragging and the rotors are getting hot. Ecxept I don't know the history of the brakes, (just bought it) Did you ever get that problem solved and if so, what was it. Back brakes have been replaced and calipers totally cleaned and free.of rust and crud.

[gmtech4]

I have a 2001 silverado and the exact same thing is happening with my truck, brakes are dragging and the rotors are getting hot. Ecxept I don't know the history of the brakes, (just bought it) Did you ever get that problem solved and if so, what was it. Back brakes have been replaced and calipers totally cleaned and free.of rust and crud.

To get the OPs attn from this site you should hit quote and ask , then it'll be emailed to him that someone quoted a post of his , ,

 

IMO you have some issues. Either stuck Pistons in calipers , calasped brake flex lines or master cyl concerns or caliper slides are dry and near seized , (1 pad thinner than the other will diag that easily )

 

If you have no experience , just take it to a garage for public safety sake and yours

[Diecutter]

I brought it in and initially was the e-brake, rusted and froze. Every time I would back up, it would turn the e-brake pads and jam it into the drum. They are removed. I'm taking it back in next week and they're going to start with the flex lines and go from there. I also read on another forum to get them to lock up again and loosen the bleeder valve and if fluid comes out and the pressure releases, it's something before that and keep going toward the master cylinder until the brake won't release after loosening a connection, it should be just before that where the problem is.

Any thoughts on that?

[gmtech4]

I brought it in and initially was the e-brake, rusted and froze. Every time I would back up, it would turn the e-brake pads and jam it into the drum. They are removed. I'm taking it back in next week and they're going to start with the flex lines and go from there. I also read on another forum to get them to lock up again and loosen the bleeder valve and if fluid comes out and the pressure releases, it's something before that and keep going toward the master cylinder until the brake won't release after loosening a connection, it should be just before that where the problem is.

Any thoughts on that?

Sounds legit , just don't throw parts at "going to start with flex lines" check them don't just change 'em

[delgadopj13]

So I am dealing with this right now myslef. Not trying to mess with brakes at all. Asked the advice of buddies who race and who have been working on cars their entire life, they came up with contaminated fluid or master cylinder is going out or misadjusted with thermal exspansion going on!!! Fluid was bad, really bad, so I went with the system flush...that helped but didnt stop it. Going with the master cylinder next.....I'm bleeding money!!! But with all the other forums that I've looked into, it always seemed to go back to the master cylinder. Good Luck!!

[Texas Red]

Had this same problem, replaced the front lines, no change...replaced the calipers and pads and it only did it once more, then it stopped and hasn't done it since. Weird.

[delgadopj13]

So here is the update! My master cylinder went out and bled into the booster pump. It was a mess, $1000 fix at dealer, Due to all the rubbing that was going on and intense heat that was created, my rotors now need too be replaced due to the "hot spots". The dealer found this potential solution on their own GM-Dealer Bulletin Board. The message board identified the solution and problem in the VIN number due to parts and manufacturer dates and location. Not big enough to be a recall but isolated enough to identify. All $$$$$ came out of my pocket. My dealer did the best they could to save me money since we were spending money prevoiusly to solve the issue. didnt charge me for work that was redone.

[sahls01gmc]

Wow, wish I would have seen this earlier. I had this EXACT same problem. It was my master cylinder. I replaced it myself for $100, took about an hour and a half. I have also replaced all 4 four calipers and rubber brake lines, but mostly due to the high miles I have.

 

Glad you got it fixed, sorry you had the dealer bend you over. I replaced the master cylinder, 4 calipers, 4 brake lines, rotors and pads for less than $600. My brakes are solid and leave me confident when pulling a trailer.

[Michael Alvarez]

So guys i have a 2004 gmc sierra 2500 hd diesel. So it started with the front driver side. i had a mobil mechanic look at it and he said it was a bad hose and replaced it. that didn't solve it so then he said it was the caliper then. Well I replaced it and everything was good. Not even 30miles of driving I smelled the burn again. BOTH OF THE REARS WERE STICKING OMG! i drove back home and they were cherry red hot. so question should i replace the Rotor? Also when i got home i bleed the rear brakes. they were good, i got fluid to the back so i know i am sending fluid to the rears. So do i have two bad calipers now? i just find it hard to believe thats it!! I have 134000 miles on it only. And i do have the star type bolt in the back does anyone know what size it is? And come to think of it when I was braking driving home when i would push down i would hear a buzzing sound is that normal? and the pedal would go practically all the way down. I had my wife press the brakes pedal and i saw no leaks whatever. Is that just telling me that the rears are bad? please some guide me in the right direction.

[jrow8162]

Same with my 05. Master Cylinder was leaking into my brake booster. Finally filled the booster up! After replacing and smoking two sets of calipers, pads, and rotors I put a new master and booster in the truck. Haven't had any problems since!