Brake caliper seized up...

[ragdoll]

Ladies and gents(loosely speaking),


The other day I noticed the rear passenger pads were just about down to metal. So I ordered a new set of pads and a rotor.

I got the caliper tool from Autozone. Replaced the driver rear pads fine and the caliper piston retracted. Put in the rotor on the pass rear fine however the caliper piston won't budge. It's pretty at the end of it's travel and I know how they can be hard to get back in at this point but I have put a LOT of force into it and can't get it.

Here's a thread with things I've tried over at AudiWorld: http://forums.audiworld.com/s4/msgs/2773986.phtml

If anyone would like to chime in with an idea, that would be great.

No one has a caliper available so buying a new one isn't an option at this point. Quickest I could have one is Wednesday and I can't go that long. I already missed work today because of this.

[Dizmm, (Old Account)]

I'll stop over tonight and check it out if i can.

[ragdoll]

I'll stop over tonight and check it out if i can.


Let's get a brain trust over here. Everyone come over... I'll supply beer. I have SoCo and Vodka we can pour on the caliper.

[ragdoll]

Also, I'm thinking there is some true seizing going on here. I unloaded 1/4 can of PB blaster on it last night and then some every hour since I got up this morning. I'll try it again around noon.

[Dizmm, (Old Account)]

Also, I'm thinking there is some true seizing going on here. I unloaded 1/4 can of PB blaster on it last night and then some every hour since I got up this morning. I'll try it again around noon.

have you called autozone to see if they have the correct tool for pushing/turning that caliper cylinder back in?

[ragdoll]

See above... I have the tool now. Mr. Hackbarth picked it up for me last night after the one I got from you didn't work. Thanks again for dropping off that stuff!


I got the caliper tool from Autozone.

[VPT]

Did you pull the caliper off the car yet? Or are you trying to work on it with the hose attached yet? I have heard of people hitting the piston a bit with a hammer to loosen it up and than turning it back in.


Where are the forum VW and audi guys? They like working on german engineering.

[Stash]

My opinion, once the cailiper is siezed like that even if you do get it to break loose is not going to operate smoothly again. You need a new caliper, I realize the issue with the time in getting the part but thats the price you pay for owning that car(I'm not bashing audis, just parts tend to be more expensive and fewer avaialable). Time for a rental car, or take the car to the dealer and get a loaner vehicle. One thing to check though, sometimes the inner lining of the brake hose can crack, sometimes this will cause a flap of material to act like a check valve in the hose. It will allow fluid to go to the cailiper, but when it tries to return the flap close trapping the pressure in the cailiper. You may want to loosen the brake hose from the cailiper and see if it pushes back in(if you didn't try this already). Also when you say you bought a rotor, you mean you are replacing the pair correct?

[ragdoll]

Updated:

I took two box-end wrenches and hooked them to the ends of the handle on the caliper tool(for more leverage). That got it to start moving. It was hard at first and got easier as it was retracting.

I kept the bleeder valve open on the caliper while doing it so as to excrete the old fluid in the caliper instead of pushing it back through the system. I the bleeder valve always had a little dome of fluid on top of it, so I could see that no air was going back in.

ANYWAYS. So after that, I closed the bleed valve and pushed the pedal to see if the caliper would do anything... pedal was like a rock from pumping it the night before for a different test. So I'm not sure if I'm actually getting true results here, or not... but it APPEARS that the caliper isn't moving(I mean, it isn't moving, but could it be because I didn't turn the car on?) Even though the last 50%-60% of compression of the caliper wasn't too hard.

Pecker...
http://upload.pbase.com/image/92975108.jpg

[EVILUTION]

I never waste time on calipers or brakes in general..... if they aren't functioning as designed ... replace them. I'm not sure who has cheap parts for audi's (or EVOs) but for most cars they don't cost more than $100.

[austinj06]

I had my driver front caliper seize up on the TT. The piston woulndt budge, so i used a C-clamp and forced that bitch back in.......oh and thank you TomKat for the advise on using the c-clamp, it worked great!

[ragdoll]

Did it function correctly after that?

[austinj06]

oh yeah, it works just fine. After i put the caliper back on I pumped the brakes and had no pressure for just a second, and after a few pumps the pedal felt stiff like it should. My brakes still function just like they did before they seized.

[ragdoll]

How seized up was your caliper? Was it just hard to push back in, or was in extremely crazy near-impossible to push back in? Mine was the latter.

You have a PM.

[ragdoll]

So I took out the caliper and have it apart on the dining room table. Everything inside is spotless. Super clean. There isn't even a speck of rust or corrosion anywhere. OK, you get the idea.

The worst is a few markes on the caliper walls from the piston spinning in it's travel. The seals are all clean, no rips or holes.

http://www.pbase.com/cdandar/image/92995269.jpg

http://www.pbase.com/cdandar/image/92995270.jpg

So for the weirdness...

The piston threads onto the caliper. The threads on both the caliper and the piston are absolutely perfect, no scratches or crossthreading. Not a speck of dirt(looks brand new). But when I screw the piston onto the caliper it's almost impossible to turn it more than 360 degrees. I put the caliper tool on to go further and it's almost impossible.

What the heck? I need some help here. So confused as to why something so clean would be so difficult?

Thanks again guys!!

Chad

[VPT]

Are the oil passage ways free of clogs? The seal isn't balling up when you turn the piston is it? Is there a burr on the pistons or cylinder wall?

[ragdoll]

They seem clear. I actually put my mouth to the oil way and blew... sounded clean to me... looks clean, too.

The only rubber seal I see is that black ring around the opening of the caliper. The piston is smooth as can be... the caliper walls are a little scratched up from the piston over the years... but nothing to catch on. Just feels like a honed cylinder wall would feel.

And like I said, the threads are super clean and without fault.

Keep the questions coming. And thanks.

[VPT]

Does it say audi on it?

Can you pull the seal out of the caliper? I would see if maybe the piston even though it looks clean and burr free, might just be snagging on the seal or cylinder wall. If not, it clears out the possibility anyways.

[Dizmm, (Old Account)]

new caliper and be done with it.

[ragdoll]

Can you pull the seal out of the caliper? I would see if maybe the piston even though it looks clean and burr free, might just be snagging on the seal or cylinder wall. If not, it clears out the possibility anyways.

With the seal out it goes in and out very smoothly... does NOT snag on the caliper wall. The seal seems to have expanded from heat or contaminates... not sure. But it looks to only need a new seal.

[Dizmm, (Old Account)]

ASM rebuild kit fixed the problem! no new caliper needed!

[ragdoll]

ASM rebuild kit fixed the problem! no new caliper needed!

You're such a `tard.

It was a combo of determination(me) and retard strength(you) that fixed it.

[Dizmm, (Old Account)]

retard strength

everyone needs a little of that every once in a while.

[ragdoll]

For those that want to actually learn from my experience...

When I rebuilt the caliper I noticed that the piston would go back into the caliper only with retard strength. When I removed the inner seal I could put the piston back in with normal mental level strength. At first I thought the inner seal just expanded due to a chemical reaction with a solvent or some other contaminant. What I ended up doing is taking a close examination to the inner wall of the caliper where the inner seal sits. I noticed a little bit of "junk" stuck in there. It was very minute but it was enough to push the seal out enough to put crazy pressure on the piston as it travels in and out.

So if you ever get a seized caliper piston... don't blow your load on a new one(unless you use it as an opportunity to upgrade[woo]). Just take it apart and do a THOROUGH cleaning, keeping the area around the inner seal in mind.

Pretty obvious stuff but it was such a small amount of foreign material and in such a funny angle, I didn't see it.

Hope it helps someone somday.

Thanks again to Andy for his assistance.

[TomKat]

new caliper and be done with it.

Much better advice.

You saved what by doing all that work yourself? $50. Factor in all your grief and Dizmm's grief. Plus you had to borrow a car while you were dicking with that old caliper.

Don't be a cheapskate and buy a new/rebuilt caliper right away. Even if it takes a couple of days to get here.

Now factor this in. I can pretty much guarantee that caliper you rebuilt will be giving you grief down the road very soon. :?

[Dizmm, (Old Account)]

Now factor this in. I can pretty much guarantee that caliper you rebuilt will be giving you grief down the road very soon. :?

Sooner than a new/reman caliper,.......yes

VERY soon as in 1 or 2 days............Hopefully not!!!

[TomKat]

I'd order up that rebuilt caliper now. 8)

[fordssuck]

I dont think he will,.....He'd have to wait 2 days

[ragdoll]

Alright alright, tuck your stings back in... sounds like you're going to have a heavy flow this month.