Stuck caliper piston

Maintenance/Repairs
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1

Might’ve done a dumb thing.

Thought I had a sticking caliper. Brake pads needed to be replaced. While I was doing that I thought I’d get any crude off the caliper piston, see if that helped. Got this based off a youtube video. Showed how you do the brake and the piston comes out and then you take steel wool to it.

While it was coming out think it went too far. Brake fluid came out.

Tried putting it back in with a c-clamp like I normally did. Was cranking and and cranking and knew in the past it could get a little tough to retract but boy was I really cranking.

Gave up. Piston’s stuck. My guess in retrospect was that the c-clamp wasn’t pushing it in evenly and now the things jammed.

Anyway are there any suggestions of what to do to get the thing retracted, or at this point does it sound like I caused damage jamming it. That leaking brake fluid is probably not the best sign in the world.

Not sure if at this point I shouldn’t just take it in. But it was one of those things where I was just trying to limp along for another 10k or so and this one sounds like it could be a costly repair.

How much you think it would cost you to fix a front frozen caliper on a 2001 Avalon? Not sure if you replace it or it can be repaired. One of those deals where it’s an old car and this repair could be the one where we decide to replace the car.

I guess I’m assuming it’s a stuck caliper.

What’s been happening is that about a year ago the car had been shuddering wildly at 45 miles an hour and up, and then at lower speeds as well. Felt and sounded like those old shopping carts when you’d get a bad wheel. Shortly afterward noticed the brakes going. Replaced pads. Problem went away for six months then came back. Replaced pads again (though thye weren’t worn down that bad) and it went away again for a few months.

Today it was back. And also I’d get a bad smell from the front tire and the rim was very hot to the touch… Looked it up on line and it said caliper.

Replaced the pads, but could not get the get the piston back in.

Here I might’ve screwed up. Had extended it out thinking that I’d see if there was any crude on it hanging it up, but I’m wondering if I overextended it and then trying to force it back in got it stuck.

Sorry for the long email, but wanted to give you a full picture of what was going on.

Based off what I’m describing does this sound like a big job and how much would you think it would to repair. I can supply you with any further information if necessary.

2

Get a new caliper and your problem is fixed for under $50. Be sure to install the crush washers on the banjo bolt then you install the brake line in the new caliper.
I would also replace that brake line, as they tend to act as check valves when they break down from the inside.

It also sounds like the original problem of shuddering may have been a warped rotor.

I would replace both rotors, the bad caliper and brake line and new pads all around. If you can swing the extra cost, it wouldn’t hurt to replace the other caliper and line.

Have you checked that a bad wheel bearing inb not causing the shudder???

Yosemite

1 Like
3

Easy fix for your problem - rebuilt caliper. Just be sure to get the correct side and if it doesn’t come with new copper washers, get at least 2. One for the top of the fitting and one below. Install the rebuilt caliper with new washers and bleed the system. Buy a quart of brake fluid (look in your manual for the type, DOT 3 or DOT 4 or in doubt, use DOT 4) and bleed all the lines with a friend in the drivers seat pushing the brake pedal. Try and flush all the old fluid out as that is likley reason the caliper piston corroded and got stuck. Old brake fluid collects moisture and corrosion is the result.

BTW, you jammed the piston in cock-eyed and likely damaged the bore or the piston soooo don’t try and save this caliper.

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Okay, great. Thanks for the replies. Had some misconceptions about brake calipers and how to replace them. Obviously will got that route.

Yea, wasn’t sure about the wheel bearing. With the car up couldn’t feel any play in the tire top to bottom, but will try that again tuesday when I have a chance to get out there. With the pads off. Was wondering that too.

The front end of this car is getting a little sloppy. Lots of clunking and the struts aren’t great so it’s bouncing quite a bit. Tierods had been replaced, but that was it.

5

The bottom of the caliper piston is dome shaped. If you use a c-clamp, you are pushing down on the top of the dome and spreading the base out into the sides of the caliper cylinder, jamming it.

To push the caliper piston back into place, you use a tool that puts pressure on the skirts of the piston, never use a c-clamp.

6

For the caliper was having problems with the one. What’s the thoughts on pairs? If you know the one is faulty can you do just the one or must you do both?

7

Considering the age, I’d do both. If the vehicle were fairly new or the calipers had been replaced in the last couple of years, then I’d do just the one.

You can do one, but with a big difference in age, you may experience uneven braking or pulling.

8

Next time you need to push the piston back in, one add’l hint, be sure to loosen the bleeder screw first. That makes the job a lot easier as the brake fluid pressure isn’t working against you. And b/c any brake fluid expelled from the caliper piston will just spill out the end of the bleeder, you aren’t pushing potentially contaminated brake fluid reverse-flow into the ABS unit and risking damaging it too.

Whenever I’ve had to push a brake caliper piston in, I’ve used a C-clamp and never had a problem. But my cars are older, maybe newer car brake systems are not C-clamp compatible.

If I thought gunk was contaminating the piston I’d not try to clean it while it was still in the caliper. I’d remove it completely and clean it on the bench. I had to do that on my older VW Rabbit one time as I recall.

9

Sloppy front suspension and noises are more likely stabilizer bar links, worn bushings, worn ball joints, or worn and failing strut mount than tie rods. Check for broken springs, too. Floppy ride could mean its time for new struts.