What causes brake calipers to get stuck ??

[ratterrier]

Hi folks,

Can anyone tell me what usually causes a brake caliper to stick? I had my rear pads replaced today, and after getting home noticed a burning brake smell and heat coming from one rear disk. I brought it back to the shop and was told that my caliper was probably sticking, even though it didn't demonstrate it there on the spot...the wheel turned normally. They said the brakes had worn down to almost nothing, and the piston came out too far.


The pads were well worn, but not enough to score the rotors. So how does the piston coming out too far cause the caliper to sticK ?? Wouldn't the original pads have stuck if that's the case ?? I'm wondering if the tech might have botched something.

Thanks,
Richard

 

[Brock94]

The piston coming out too far doesn't make any sense to me-- even if the pads were worn to the metal backing (maybe someone with more experience can correct me?).

If the slides and mounting pins weren't greased or were all gummed up, the caliper could stick. The rotors on my 94 were badly warped and I think that was the reason.

I've also read about brakes getting stuck because of a blockage in the hydraulic system.

Hope this helps...

 

[410Fortune]

rear calipers are $12 ea at Autozone.
They wont stick unless the proportioning from the master cyl is wrong, the ABS is jacked up, or if like stated above the slide bolts are not lubed or gummed up.
It is normal for the pads to rub on the rotors, there is nothing pushing them back away from the rotor......

Air in the system can cause problems too.
The piston on the caliper cannot come out too far, even if the pads are to bare metal, if both pads are seated on the caliper and mounted on the rotor the piston cannot travel far enough to come out of the caliper.
Also the dust boot should not be torn or un seated.....

If they just did the brakes, and they are dragging after the work they performed, its their fault not yours. if the piston comes out of the caliper it is usually because the pedal was pushed when the caliper was loose (not mounted) I say replace both calipers, bleed, and be done with it.

 

[Heavymentill]

The rear brakes also house drum style Emergency brakes. I never trust brake shops as they overcharge and as in your case F stuff up.

 

[410Fortune]

OH yeah I forgot the smell and dragging could be caused by the e brake shoes, have fun with that! They can be adjusted just like old drum brakes. They are a PITA, but the good news is hardware kits are finally avail to replace them from parts stores like Carquest and Napa.....Ford gets like $100 or somthing for the kit which is BS.

 

[CDW6212R]

Calipers very often will drag when the vehicle has set unused for a long time. I have had two vehicles do it. If it happens, and you suspect that the cause is storage, change both calipers. Don't mix old and new calipers. Good luck,
DonW

 

[thewishkah]

well you another uncomon thing that will cause them to stick , I know cause it happend to me twice the piston melted and would not return (I drive like an a$$hole alot of the time) not really but I speed alot and slow down quick and well I guess its not good for the brakes lol.

 

[ratterrier]

Thanks for all the advice. The pistons coming out too far just didn't make much sense to me. We're talking about milimeters between goog and bad pads. I was thinking maybe the shop didn't apply brake libe, and had even brought some of my own when I went back...but they assured me they always apply it (what else).

While I was there they poked around the brake cable and that looked OK, and kept pushing the pedal and that seemed to work OK. The wheel spun as it should when elevated. Then one of the guys took it out for a 10 minute drive, came back and said the problem may have freed itself up and the rotor wasn't hot after his test. I, being trustworthy, didn't feel for it in front of them...but when I got home it was indeed hot. Maybe the Raybestos pads they used are out of spec ? Or no brake lube used. I can't imagine an stuck caliper being intermittent, but if knew it all I wouldn't be asking. What I do know is I didn't have this problem before they touched it.

Unfortunately I live in PA now, and this failed inspection. So if you don't have it fixed at the sho[ that inspects you then you pay again for re-inspection. It's a bad system that leads to conflict of interest...don't know why they permit it. Back in NJ inspections were part of the registration cost, and you could choose to pay a mechanic or go to a free public inspection station.

Thanks again,
Richard

 

[TSTONE]

in case anyone cares - a caliper piston does have the ability to push out to far and blow its seal if a pads and rotor have both gone below minimum thickness limits - which is part of the reason you need to gage rotors (and drums - for wheel cylinders).

 

[ratterrier]

Hi Tstone,

That's interesting to know. In my case the rotors are probably OK (they passed inspection) and my vehicle only has about 48K miles. The pads were real low (and probably below minimum thickness, which is why they needed replacing. But what would be seen if these seals you mention blew. Wouldn't brake fluid appear anywhere?

Also, wouldn't I have had a seizing problem with the original pads? The piston was pushed back in to accept the new pads.

Thanks

 

[TSTONE]

My comment was more for general knowledge - your particular situation was more likely stuck slides. and yes if the caliper pistons or drum wheel cyliders extend to far they will leak fluid.