Brake problem

I have a 2001 mustang GT. I have 2 front calipers that are sticking. I changed both calipers twice, new brake hoses, bled all the wheels and the master cylinder. Any idea why the calipers won’t release? Any advice would be appreciated.

The ABS module?

Are you certain that the hydraulic pressure on the calipers is releasing? Do you get a good squirt of fluid when you crack open bleed valve? Warpped rotors, defective or improperly installed pads, over torqued wheels are other possibles to check.

Did you grease the caliper slides with hight temp brake grease?

Busted, I’m gonna look into the ABS module if a new caliper doesn’t do the trick.
Turbo, when I open the bleeder it doesn’t really squirt all that much. So it would appear I got a sticky piston. I’m returning the caliper for another one today, I’m hoping that’s the problem. The rotor isn’t in great shape, but it looks decent enough. I might just get a new one for the heck of it.
Knfenimore, the calipers come pre greased and they seem to slide well on the pins.
I’m gonna change the caliper in a little while, I’ll let y’all know how it goes.
Thanks for all the advice :slight_smile:

The 4th caliper I got for driver side works! It took 3 for the passenger side, 4 for the driver side. I will never buy calipers from Autozone again. Idk who remanufactures these calipers, but I imagine it being a sweatshop. Maybe autozone just puts the returns back on the shelf because they are lazy and/or incompetent. Idk…¯_(?)_/¯ I appreciate y’all taking the time. Thanks

I’ve purchased a lot of parts from Autozone and never had to return anything. Don’t take this the wrong way but brake calipers can easily be installed the wrong way and brake bleeding the front calipers takes a skilled hand. The odds of getting 7 bad calipers is astronomical so that’s why I commented.

" I will never buy calipers from Autozone again."

My first question was going to be where are you getting these calipers.
I bought a pair of calipers from AZ once ~10 years ago and one was dragging.
At least the store was nearby to exchange it for another.

It seems that some low life auto parts stores don’t like to deal with returns . . .

So some poor slob will be buying the returned defective part, won’t be told it’s bad, and will be second guessing his work and his diagnosis

I’ll go a little off topic . . .

A few months ago, I diagnosed a bad hybrid battery pack for one of our fleet’s Civic Hybrids

I was 100% sure of my diagnosis

I removed the battery pack and exchanged it for a “new” battery pack from the Honda dealer. They delivered the battery pack and picked up the old one. Anyways, after installing it, the thing still didn’t work.

I was quite certain the battery back they brought me was no good. Rather than dealing with it . . . I had tons of other work, and my boss thought it would be more efficient if I got work done, instead of working on a mystery vehicle . . . we sent the whole car to the dealer that sold us the battery pack. Turns out I was right and the battery pack they sold us was no good.

“Through the grapevine” I heard that they actually have a lot of bad “new” battery packs in their warehouse.

I put new in parentheses because I’m fairly certain the battery pack was remanned. The car was a 2003, and I can’t imagine there’s too many brand new battery packs in existence

I wonder what happened to the first battery pack they brought me, the one that was no good


Various combinations of bad rotors and unevenly worn pads can contribute to this symptom sometimes. If the problem returns, suggest to first replace both rotors and install new pads on both front wheels. If you are at all in doubt if all the parts are there and installed correctly, good idea to bring a pro for a look-see at least. What with all the parts, wear indicators, anti-squeal shims, other fiddly bits, there must be a thousand ways to mess up when configuring disc brake systems.

I’ve bought a lot of parts from AZ over the years and have had very few problems. Getting 7 bad calipers in a row is very baffling and unusual. Those are Lotto odds and while the story will be impossible to sort out it would certainly be interesting to know the how and why behind it.

“Getting 7 bad calipers in a row is very baffling and unusual.”

…and nearly impossible in my book.

I can’t tell you how many times I have heard brake calipers were installed upside down with the bleeders on the bottom.

Missleman and Knfenimore the calipers were installed with the bleeder on top (correctly). And even if they were bled wrong, air = squishy peddle, not stuck calipers right? I’ve bled many cars, never had a problem before. Its 5 bad calipers btw, 7 is counting the two that work. I know it’s unbelievable to go thru so many. But when you crack open the bleeder on the stuck caliper, it should release. Correct?

Circuitsmith, I went to 3 different autozones. I might have got the ones people returned. Idk…

George, I ended up buying new pads, roters and brake hoses in between all the bad calipers. Autozone should do this more often, some people end up coming back to buy other stuff they don’t need, lol.

Maybe it was another issue. Maybe it will all of a sudden get stuck again. As far as I know, when you open the bleeder, it should unstick. Unless the piston or pins are sticking. Those 5 calipers stayed stuck.
Could there be another reason this happened, sure. But what is it?
“there must be air in the system” how and where would air cause calipers to stick?

I also want to add, most of the employees at autozone are very nice people. Many of them don’t know much about cars, but the ones who hire them don’t expect them too either. I would like to think they didn’t purposely put bad calipers back on the shelf. Maybe they get left around and find there way back on the shelf accidentally. Maybe the place that remanufactures them is at fault. Maybe I somehow f-ed up, lol. But if I messed up, I’d love to know how. I’m just as baffled as a lot of you guys. The only thing I can see is if I had air in the system. But like I said, air in the line shouldn’t make a caliper stick. If I’m wrong about that, let me know. Or if there is air somewhere else in the system that could have caused this to happen.

“I would like to think they didn’t purposely put bad calipers back on the shelf.”

I, on the other hand, think that autozone would purposefully put bad calipers back on the shelf, rather than handling it as a return and sending it back to wherever they got it, for a credit

I’m cynical, no doubt, but I believe autozone would think it too cumbersome to handle the paperwork handled with a bad part

It’s far simpler to just put it back on the shelf and sell it to the next guy

I’m not condoning it at all

I’m 100% against it

But it’s what I would expect them to do

If there is crud in your brake fluid it can plug the return ports in the master cylinder and cause the calipers to stick or if the master cylinder has been replaced the pushrod length can be off and close off the return holes. However if this happens it should cause the right front and left rear brake to stick together or the left front and right rear.

db4690, you’re probably right.
Doing it that way might even make them more money. I ended up buying front pads, brake hoses, fluid, roters… Stuff I really didn’t need. I was a couple more bad calipers away from replacing hard brake lines and buying a master cylinder lol
After that I would have bought a for-sale sign.

I was thinking blockage of some sort as well, oldtimer. But like you said, if it was in the master cylinder it would have affected the rear as well. After going through a few calipers, I was sure it was internally damaged brake hoses. When that didn’t fix it, I didn’t know what to think. The only thing that made me keep exchanging calipers, is when I cracked the bleeder and they stayed stuck. From what I hear, that’s a bad piston.

It’s also possible that AZ got a bad run of remanned calipers shipped to them. A lot of remanufacturing facilities do this stuff on an assembly line basis and being mechanically skilled is not necessarily a requirement for employment. Speed in stuffing a square peg in a round hole is…

There was a huge engine remanufacturing facility in OK City some years ago and they used to run ads in the paper for assembly line help. “Engine builders needed. No experience necessary. 7.00 dollars an hour”.
I got involved in several installations of long block engines from this place and there was much grief.

One of them was a new engine that used a quart of oil per 10 miles. After much stonewalling and trying to lay the blame off on me it was discovered after the engine was taken back out and disassembled that every single one of the oil control rings on all 8 cylinders was missing.
That was either the clumsiest move of all time or a disgruntled 7 dollar an hour engine builder sabotaging the engine before moving on to a job at McDs.

There was a VW engine reman facility in Tulsa that shipped out 75 engines and 71 of them failed shortly after installation; including one of them that I installed and which lasted less than 1000 miles.
There are other stories but you get the point.

It would have been interesting to remove a few pistons from the stuck calipers just to see what was going on in there.

“That was either the clumsiest move of all time or a disgruntled 7 dollar an hour engine builder sabotaging the engine before moving on to a job at McDs” LOL! ok4450 that’s exactly how I pictured it, an assembly line with poorly paid/trained people slapping things together.