frozen piston in front brake caliper

[lovetoski]

So I'm planning on the 4 Runner brake upgrade this summer. Noticed my pads were thin, bought new, discovered a frozen piston. No time to do the full 4 Runner swap now, so I bought the caliper rebuild kit. I've done this on my 80 (both ft and rr) and it's pretty easy. However, the frozen piston has defied all my attempts to remove it. Penetrating oil, air pressure, heat, cursing.

Any magic tricks?

The other caliper was a piece of cake.

Thanks!

 

[brett76]

is this to get them back on? or to get them off

 

[cruiser88]

yep if memery serves me right use a grease fitting were the bleeder goes and pump it full of grease till it comes out thats how we always did it the junk yard i think its the same concept on land cruiser somebody feel free to correct me if im wrong if had to many already

 

[lovetoski]

is this to get them back on? or to get them off

The calipers are offf, it's to get the one stuck piston out of it's cylinder.

 

[lovetoski]

yep if memery serves me right use a grease fitting were the bleeder goes and pump it full of grease till it comes out thats how we always did it the junk yard i think its the same concept on land cruiser somebody feel free to correct me if im wrong if had to many already

That seems like it might work - would get lots of pressure. Is it hard to get the grease back out? Does a regular grease zirk thread into the bleeder hole?

 

[cruiser88]

just use a good grease gun ya a regular gun will work rob one of your grease fittings somewere on your rig it should screw right in if not go to the store they will have one im sure it will anyway and once you get it all apart it will clean really good if ya got a vice use it and make sure you have a clean line of fire

 

[cruiser88]

just one more thing to keep in mind ive had to throw a couple away because the piston wall was so bad it would not hold proper pressure the cy. literally cut into the cylinder wall before i got it out

 

[lovetoski]

just use a good grease gun ya a regular gun will work rob one of your grease fittings somewere on your rig it should screw right in if not go to the store they will have one im sure it will anyway and once you get it all apart it will clean really good if ya got a vice use it and make sure you have a clean line of fire

Cool! I'll give this a shot first thing in the am. Will post back w/results.

 

[cruiser88]

ya will get it

 

[KLF]

yep if memery serves me right use a grease fitting were the bleeder goes and pump it full of grease till it comes out thats how we always did it the junk yard i think its the same concept on land cruiser somebody feel free to correct me if im wrong if had to many already

I can't see how this could work. I guess I'd like to see if this can be done, I'm really curious. How do you keep the grease from squirting out the brake line fitting? And, wouldn't one of the "non-stuck" pistons pop out first?

My solution: BEFORE you remove the caliper from the knuckle (probably too late for that now), slip the brake pads out of the caliper, then get int the truck a STOMP on the brake pedal. Let the hydraulic pressure of the brake system force the pistons out. The rotor will keep them from popping all the way out and getting brake fluid all over the place.

 

[60wag]

I too would expect that you could get much more force from the brake system than from a grease gun.

Don't spend too much time trying to free up the stuck piston. A whole new rebuilt caliper is pretty cheap.

 

[spotcruiser]

Doug,

I've had the same problem and I just use compressed air. Put the other three pistons back in, put a piece of wood between the pistons (the wood needs to be about 1/2 inch narrower than the space between the pistons on each side) and hit it with air. You have to, of course, plug the second brake line fitting if you are working on the passenger side caliper.

Todd Bull.

 

[euclid]

I had the same problem night before last. My solution was to remove the caliper and tap on the piston using a small hammer and a small brass drift. I got it to go back in, and it seems to be working.

 

[cruiser88]

when i started working on cars i screwed up a couple of calipers subaru land cruiser a little both with the guidence of 1 old man back east this guy is well known sort of a god in the caving community 4 wheeling community his name was jim hixson maybe some would know him in here maybe not being so many in here is from out west yes you have to block off the brake line and keep the good ones if you chose to keep them from coming out but i never blocked the other cyclinders because when rebuilding a caliper i never rebuild just one cylinder i prob. should have mentioned to block the brake line just figured he would know that as far as air when a cylinder is sidew. or somewhat in my experience just will find its way around its not really about the pressure always yes it needs pressure but at the same time it needs a thick lubrcation with some pressure not a whole lot. the times i screwed mine up i ve beat, used air just made it worse needless to say i had to toss them. the cylinder walls was just to bad to reuse. in the real world we just toss them out the window and buy new ones but for your a poor as meback in the day sometimes your just willing to try the oldtimers advise and of course he proved me wrong and i had to admit it .its true what they older is wiser all good comments in here

 

[cruiser88]

on my prer statement when trying to get the stuck cylinder out i put the pads back in when im pumping of course i got it in a vise .

 

[cruiser_guy]

I wouldn't even bother with the caliper if the piston is that stuck. I gave up trying to rebuild brake parts on my own years ago. The money saved for the work and ho-hum results were simply NOT worth it in my books.

 

[cruiser88]

anymore thats what i do hell of alot less

 

[lovetoski]

Well, some of you might be saying "I told you so" but I did give it the full-on IH8MUD effort...tried to unstick the frozen piston with air, liquid wrench, heat, a hammer + drift, a pipe wrench, and grease. No luck, I was utterly defeated. Broke down and bought a new caliper. Actually bought two calipers. Everbody I talked to said that it was a bad idea to have one remad'ed caliper + one home rebuilt caliper. They are brakes after all. So, two new calipers, 60 minutes to install and bleed, and I have brakes that work great.

Lessons learned:
1. If your brakes work great, but your piston boots are "scruffy" then buy the brake rebuild kit and replace the boots. It'll keep the pistons from freezing...
2. If you have a frozen piston, just buy two new calipers.
3. Sometimes trying to save money isn't worth the effort.

 

[import silvia]

There is no reason why a well home rebuilt and re'maned caliper cannot get along together. With the possible exception of honing the cylinder wall there will be very minimal difference between the two.

 

[cruiser88]

oh hell ya tried