fun with calipers (1 Viewer)

[Poriomania]

My plan for rebuilding the my calipers today has run into a snag. The guy I had talked to about popping out the pistons had already left for the day when I went over to the shop and the guy that was there wouldn't do it. So I stopped at two other shops who wouldn't touch them and ended up at my Toyota dealer who had a porter try popping them with a burst of compressed air. The pistons didn't move.

So should I wait till Monday to see if the original guy with more skill etc. can get them out or since they didn't move are they toast?

 

[LandCruiserPhil]

Assuming that you removed the rubber boots air should push the piston out. If not the pistons more then likely corroded and will need replacing anyway. I have done the rebuild method once and never again it is tedious and if you tear one of the four rubber boots (ez to do) your fawked. Personally I would buy rebuilt ones.

Phil

 

[Rich]

Well, it seems to me if you reinstall the calipers, one on the rotor, and one not, refill the brake fluid, then you can use the brake pedal to push out the pistons on the "rotorless" caliper. You would then need to rebuild and reinstall one caliper prior to repeating the procedure for the other.

After you get the pistons out the condition of the caliper cylinders will tell you if rebuilding is appropriate or not. The caliper bores must be free of corrosion, pitting, etc. Likewise for the pistons.

Post rebuild leaking is generally due to bad surfaces on the pistons or caliper bore, either from corrosion, exessive wear, or damage due to improper disassembly or reassembly.

 

[Poriomania]

Assuming that you removed the rubber boots

Phil

That would be too much of an assumption, forgot to get those off. Will do that and retry monday.

 

[Gumby]

Air should pop them out. I never rebuild them. if you can't get them out with a blast of air, you need parts. At that point rebuilt calipers look pretty good. Let someone else do the PIA job of getting the pistons back in.

 

[landtoy80]

Can you move the piston with a C clamp?

 

[alia176]

Even if you're succesful in rebuilding the calipers, chances are, they will leak in the near future! Nowadays, you can buy loaded (with pads) rebuilt calipers for a decent price with a warrantly of some sort.

Good luck.

 

[Junk]

Even if you're succesful in rebuilding the calipers, chances are, they will leak in the near future!

TOTAL BS. PLEASE SEPERATE FACT FROM FICTION.

IF YOU REBUILD THEM CORRECTLY, THEY SHOULD NOT LEAK AT ALL. JUST REBUILT MINE TODAY AND THEY WILL NOT BE LEAKIN.

LEAK?

 

[OGBeno]

TOTAL BS. PLEASE SEPERATE FACT FROM FICTION.

With authority!!!!

 

[Poriomania]

Had to cut short for a wedding tonight and work in the morning, (will be walking). I'm going to take the boot off tomorow and drop it by the shop on Monday morning to have the pistons taken out.

Junk: any tips on a "correct" rebuild?

 

[IdahoDoug]

Agree the leak comment is BS. These are totally rebuildable and done with nominal attention to cleanliness and detail will be a success.

A neat trick I've never had to try is to get a zirc (grease nipple) fitting that fits the threads for the hydraulic line (apparently common thread) and use a hand grease gun to force the pistons out. You'll have a few minutes of extra cleanup to get all the clean grease out, and use a good degreaser/brake cleaner fluid, but this is an excellent idea for the home mechanic w/o air. A hand grease gun can generate tremendous pressure.

DougM

 

[Gumby]

As much as I didn't like the "push it out with brake fluid" idea, I like it way better than push it out with grease. you don't want to introduce petroleum based products into your brake fluid area. Sure you can clean it out very well, but thats a ton more steps and uncertainty into the project. If they don't pop with air, then I would be concerned with the integrity of the piston and the bore. If they are damaged, then as Ali says, they will leak prematurely or seize.

I pretty confused. You are going to pay someone to remove your pistons. but you are going to try to rebuild them yourself? You don't have the confidence to try and get the pistons out, but you have the confidence you can inspect them for problems and put them together correctly?

$110 each for rebuilt calipers, loaded with premium lifetime pads, new copper washers, slider pins, bolts, all rubber parts, etc. Why screw around once every 100,000 miles?

 

[alia176]

Oh Junk,

If your pistons are as corroded as the other fella's, yours will leak too. GUARANTEED. Unless, the other fella is purchasing new chrome/SS pistons, it ain't worth rebuilding a caliper. Maybe CDan can chime in as to the cost of new pistons?

Ali

 

[Poriomania]

I pretty confused. You are going to pay someone to remove your pistons. but you are going to try to rebuild them yourself? You don't have the confidence to try and get the pistons out, but you have the confidence you can inspect them for problems and put them together correctly?

$110 each for rebuilt calipers, loaded with premium lifetime pads, new copper washers, slider pins, bolts, all rubber parts, etc. Why screw around once every 100,000 miles?

It's not so much an issue of confidence of getting the pistons out as it seems worth the extra few dollars to have someone with air a couple blocks away do it.

I don't know that the pistons are corroded I hadn't removed the boots from the pistons before having someone try to do it so that may be the problem with getting them out. I thought I'd remembered all the steps so I didn't reconsult the manual.

Overall it very well may not be worth the effort, but between people on this board and other people I've talked to there was about a fifty fifty spilit on the difficulty: value ratio for doing this procedure so I thought I'd try it and see.

 

[Gumby]

Fair enough. I thought you had compressed air. I must have not read the whole post.

 

[Beowulf]

>> Overall it very well may not be worth the effort... <<

Gary,

I believe the effort has been overrated. I used CO2 and popping them out after the boots were removed was quick and easy. Be sure you use a block of wood or other material to protect the pistons as they come out with a lot of force. Do NOT get your fingers in there or you'll get the nickname of stubby.

Installing the new rubber boots was also very easy. I think those that were having problems were trying to put the boot on before the pistons were fully seated back in the caliper housing. I would rate the whole job as 1 banana; 1/4 banana for removing the pistons and 1/4 banana for installing the new boots. The other 1/2 is removing the caliper, cleaning everything, and installing.

I'm also not too keen on Doug's suggestion for using grease. Maybe a trail fix if no other option was available, but not in your garage. FWIW, I'm pretty sure Doug has never used the grease zirk method himself.

-B-

 

[Junk]

Oh Junk,

If your pistons are as corroded as the other fella's, yours will leak too. GUARANTEED. Unless, the other fella is purchasing new chrome/SS pistons, it ain't worth rebuilding a caliper. Maybe CDan can chime in as to the cost of new pistons?

Ali

because you are assuming his are corroded. have you seen them? do you know they are?

rebuilding them, if they are salageable does not take long and is not complicated, oh, and gumby has no idea what he is talking about (as normal ) related to price. list price for 97 calipers is about $211/ea with ss of about $160 + core charge.

 

[Gumby]

Just replaced mine for $110 loaded each. Cost, rebuilt.

Who pays list?

 

[Junk]

you have the inferior ones dumb-bunny, just look at your year

 

[quicktodoze]

I second Beowulf on the ease of the rebuild. Easy, maybe not 1/2 banana but still easy.

The trickiest part for me was getting the pistons out. I'd put compressed air to it and only one of the pistons would pop out. You have to barely push it back in to allow air pressure to build again to get the other ones out. What I ended up doing was putting a block of wood in the middle, then applying air. One piston would pop out. Slide that one just barely back in to seal the chamber and put some wadded up paper towels between the piston and the wood block. Blow more air and another one or two would pop out if you did it right, or the original would pop out again and you'd need to stuff more paper towels in there. Repeat until you've got the last one out and then if you didn't push the others in too far, you can wriggle them out with your hands. Not hard, just tricky.

Putting them back together was also easy, once you realize that you should slide the new boot onto the piston BEFORE you put it back in the caliper. For the fronts, install the boot onto the top lip of the piston, then slide it into the bore. Once the piston is all the way in, smooth the boot around the raised edges to allow installation of the metal ring.

The strategy for the rears was a little different. Put the boot on the very bottom part of the piston (the closed end that goes into the caliper), not on the lip, then install the boot into the caliper. You'll have the boot in the caliper, with the piston sticking all the way out of the caliper, held in place by the boot. Now push the piston down into the bore, making sure that the boot slides all the way up the piston, onto the lip on the top of the piston where it should be.

Good luck.
Nic