seized brake caliper piston

[pound3151]

I have a problem with a seized brake piston. I just put 4 new rotors on and rebuilt 3 of the brake calipers. They all seem fine. I got to the last caliper and started to rebuild it, but I'm only able to get 3 of the pistons out, as the fourth seems seized in there. I tried blowing it out with compressed air while holding the other 3 in and also I hooked the caliper back up to the vehicle with the same three held in, did a quick bleed job and tried to build up some pressure to force it out of there. That sucker dosn't want to budge.

Any advice on how to get this out of there asap would be extremely helpful 'cause the truck is still on jackstands until I can get this last caliper done. Thanks --Brad

 

[IdahoDoug]

If you can't determine in which direction it's jammed (fairly tough to see, really) then you'll have to resort to greater force. Consider first seeing if you can tell which way it's jammed and use a dowel or other non marring device to hammer on the high side. No luck or can't see, take it to a hardware store with a variety of C clamps so you can buy one that's perfectly sized and oriented, then back home use wood to again prevent marring as you try to force it loose. No luck again, take it to a mechanic AFTER you've called around on the phone and found one who seems to have a strategy and or special tool to handle this. I say this last because any mechanic will figure they can force it loose, but then they'll just take your money and hand it back to you with no knowledge whether they've distorted the piston or not. You might also see if you can find a replacement piston to have on hand if you ruin it. As a final comment, there's a chance you might also damage the cylinder wall with force so best to see if you can determine with a precise measuring device or metal straight edge across the piston face to see which way it's tilted.

DougM

 

[pound3151]

Doug, it doesn't seem to be tipped to one side in there. I can see a tiny bit of rust forming at the top though. I tried several solvents that I had but no luck. I was able to force it about 1/16 inch back in with a c clamp but that didn't loosen it either, and I'm afraid that if I push it much further I won't have anything to grip it by. Thanks for the advice though, if I don't come up with anything else I'll probably be calling around tomorrow.

Brad

 

[IdahoDoug]

If you can find a replacement piston, I guess you can resort to more destructive removal methods with the limited access you have to get tools in there. Bummer is many of these will distort the piston in a way that will/may jam it even worse. With the rubber seal removed can you get any better penetration with good penetrating oil? I don't know how hard that piston is in terms of drilling, but drilling all the way through so you can put a steel rod through and twist back and forth would get penetrating oil in and loosen it. Getting drill chips out is no big deal as there's just a hollow space behind it to clean followed by a bit of extra bleeding before the piston goes in.

When you put the caliper back on the hydraulic line, did you use a wood block to hold the others back while pushing on the pedal? I had good luck with this though the FSM dimensions for a wood block were way off...

DougM

 

[robbie]

I use two long handle pry bars to pull these pistons out. I hool the tip under the lips of the piston and then pry, some times harder then others but never fails. I usually use 12 in or better prys. It is a little tricky but works well. Later robbie

 

[Dan_J-spec_fj62]

i had the same thing happen... only it was stuck out....2 new front disks, calipers, hoses and sets of pads later (i belive in changing brake stuff in pairs) i was ok... i got the stuff at autozone (this was before i knew about C-Dan god of oem parts) any how set me back a bout $400 in parts and maybe 8 hours of labor (my own) in light of your situation i minght just get a new caliper and try and rebuild yours when you are not desperate to drive your cruisser....

dan

 

[pound3151]

I finally got the piston out after a long struggle, a lot of muscle, and beat up hands. The piston has very light markings on it, they look like tiny rust dots and very minor scarring. I can't find another piston locally, my question is, can this piston be reused or should I leave the truck in the garage for another week. I know that is hard to answer without actually seeing the piston, but any advice would be helpful. By the way, how much were those calipers from auto zone? Just curious, I'll probably drop c-dan a line on monday anyway.

 

[RavenTai]

Clean it up with some steel wool, don’t go deep just take off the high spots, throw on the new seals lube it with the “lithium soap base glycol grease” (???) Specified in the FSM and give it a try,

I would rather have a caliper that was rebuilt by me than one that sent to the lowest bidder, the one you would get from AutoZone was likely in much worse shape than yours before the rebuild

 

[Beowulf]

Haven't you noticed that Dan is at our beck and call 24x7? Seriously, drop C-Dan a line now as he frequents this forum on weekends and the store is open on Saturday.

-B-

 

[pound3151]

I tried dan twice today but no luck. Hey, the man's got to have a life too. I lightly wire wheeled the rough spots on the piston and steel wooled it. It is lightly pitted about 1/4 of the way down, as is the caliper. Thinking about trying it but I don't want to ruin the new rotors if it sticks.

 

[cruiserdan]

Why didn't you leave a message on my extention? I have been working the front counter all day while you guys are breaking your cars...........

 

[pound3151]

well dan, what would your take be on this? replace the piston and hope for the best or replace the whole caliper? I'm runnig out of ideas and am not sure about pushing my luck too far and putting that piston back in there.

 

[Beowulf]

The pitted piston and cylinder stuck once and will probably stick again. If you can't get it cleaned up like new then I would replace it. You're talking about your brakes here, not a shackle on the bumper.

-B-

 

[Dan_J-spec_fj62]

umm i cant' rember right off hand.... and the recipt is burried under a bunch of crap i am meening to get too tommorw.... if i had known about Cdan b4 i would never have even gone neer auto zone but its $$$ aready spent.... if they go again i'll get OEM from Cdan. i think it was like $160 each with a core charge....

 

[pound3151]

Thanks for the help guys. I went with a new piston from c-dan and I tried to hone the cylider by attatching steel wool to my drill. It cleaned them up pretty good. Everything seems good to go once the new piston arrives.

 

[cruiserdan]

It left for your door this afternoon......

 

[Junk]

I don't know what the problem is with Cdan. Dang it. I asked Woody to put a button somewhere in this forum, than when pressed, sends a sharp poke to get Cdan's attention. That way if he's in the little boys room or sleeping at 3am he knows we need him now

Seriously, the guy is here like all the time. But when he's not, leave him a message. We are in 2004 now and vmail does work.

 

[Beowulf]

>> We are in 2004 now and vmail does work. <<

Yes, but an urgent 911 text message to his cell phone works even better.

-B-

 

[landtank]

We are in 2004 now and vmail does work.

That's funny, I left you a VMail yesturday morning about having some cash for you and haven't heard back.