Brake Caliper Rebuild (4 Viewers)

[PabloVTA]

awesome faq!

I've been wanting to do this for a long time.

Did you submerge in a tank at all? or all rags and towels?
What brake fluid are you using now?

If the pistons are pitted, can you purchase just those? or do you find out after all this work that you need a rebuilt set as a replacement?

any changes to your caliper bolts to fight off the loosening curse that many have had?

 

[bowyer2002]

great write-up, description & photos too!

looks like it just took time, not necessarily difficult.

another post to encourage home shop repairs!

now if i can just get my wife to let me spend the $$ i save doing the repairs/maintenance at home in lieu of the dealer!!

 

[concretejungle]

great post. I have been planning on rebuilding my calipers. Now i will have additional ammo for the job. Thanks.

 

[Slomo]

awesome faq!

I've been wanting to do this for a long time.

Did you submerge in a tank at all? or all rags and towels?
What brake fluid are you using now?

If the pistons are pitted, can you purchase just those? or do you find out after all this work that you need a rebuilt set as a replacement?

any changes to your caliper bolts to fight off the loosening curse that many have had?

Thanks

I did not submerge just rags, towels, Brakleen, and a razor blade to shave the pistons.

Didn't check on whether I could replace just the pistons, perhaps cdan will chime in.

I just used Blue Loctite and torqued to factory spec, 95ft/lbs IIRC.






Thanks all for the complements, glad it will be useful. Definitely more of a time thing than a major skill thing.

 

[fjfar80]

Great information and well laid out, I think you forgot one step though:

Step: 1 - Put on latex gloves.

 

[tominator]

Way to break this down..thank you!

And to think I was going to buy new calipers...not anymore!

 

[Slomo]

Great information and well laid out, I think you forgot one step though:

Step: 1 - Put on latex gloves.

Thanks, that would definitely help. Took a couple of days to get all the brake dust out from under my fingernails. The price for being lazy. ;p

 

[turbocruiser]

Thanks

I did not submerge just rags, towels, Brakleen, and a razor blade to shave the pistons.

Didn't check on whether I could replace just the pistons, perhaps cdan will chime in.

I just used Blue Loctite and torqued to factory spec, 95ft/lbs IIRC.






Thanks all for the complements, glad it will be useful. Definitely more of a time thing than a major skill thing.

Again, excellent write up! I have an after the fact question - if I understood correctly, you cleaned the pistons by shaving with sharp razor really carefully and they look terrific - but, what did you do for the sleeves the pistons ride in? I'm wondering if a very fine synthetic steel wool would work on the inside face of our sleeves and for that matter if it would help the pistons as well? I'm thinking that my potential to knick the piston is pretty high given the way my face looks each morning after my shave! Is there something that you have heard in regards to avoiding that? Thanks Again!

 

[Slomo]

I have an after the fact question - if I understood correctly, you cleaned the pistons by shaving with sharp razor really carefully and they look terrific - but, what did you do for the sleeves the pistons ride in? I'm wondering if a very fine synthetic steel wool would work on the inside face of our sleeves and for that matter if it would help the pistons as well? I'm thinking that my potential to knick the piston is pretty high given the way my face looks each morning after my shave! Is there something that you have heard in regards to avoiding that? Thanks Again!

I used the razor at a very low angle, maybe 15* relative to the piston surface or just enough to make the sharp edge just touch the piston surface. I think the only way you could nick the surface would be if you used the corner of it or used it in a cutting motion. Think barber shop shave with a straight blade. I imagine a fine steel wool would work but I would do in with the direction of the surface machining. I don't remember which direction that is in the piston cylinder. Basically with common sense you will be fine.


FWIW I am pretty sure I used the razor blade inside the cylinders as well. I would also use a brand new blade, perhaps even swapping mid job to keep a perfect surface to contact the piston.

Hope this makes sense.

A

 

[turbocruiser]

I used the razor at a very low angle, maybe 15* relative to the piston surface or just enough to make the sharp edge just touch the piston surface. I think the only way you could nick the surface would be if you used the corner of it or used it in a cutting motion. Think barber shop shave with a straight blade. I imagine a fine steel wool would work but I would do in with the direction of the surface machining. I don't remember which direction that is in the piston cylinder. Basically with common sense you will be fine.


FWIW I am pretty sure I used the razor blade inside the cylinders as well. I would also use a brand new blade, perhaps even swapping mid job to keep a perfect surface to contact the piston.

Hope this makes sense.

A

Perfect! Thanks.

 

[slo60]

Just saw this. Thanks Slomo for the great write up. Will be rebuilding my calipers soon.

 

[96r50]

Now hold the boot/piston up to the cylinder and work the lip of the boot into the outer channel of the cylinder wall. This is a bit tricky and takes some patience. You can use a small blunt object to push the last of the boot into the channel but be very careful not to cut the boot. I accidentally poked a hole in one of the boots but it is not a major deal as the ring placed in the caliper itself seals the piston and the boot just keeps dust out which it can effectively do with a small hole poked into it. I was able to work it in almost entirely with my fingers but I have small girly hands. During this step you will have the piston and boot in your hand and the piston will not be in the cylinder at all until you get the boot in place in the outer cylinder channel. Without allowing the piston to slide out of the boot or the boot to pop out of its channel in the cylinder gently push the piston in with your finger tips. Do this very slowly and do not force it, if you do you can easily damage the boot or the cylinder wall. After getting the piston started in push it about half to two thirds of the way in and gently work the end of the boot around the piston into the channel in the brake pad end of the piston and push the piston the rest of the way into the cylinder.

First off, big thanks to Slomo for this thread. Having read it I was pretty sure I could rebuild my calipers (and they needed it badly). Almost everything went the same as explained in this thread, I just have a different way to insert the rear pistons. I tried and tried the way described here, but my hands aren't small and girly enough I guess

Note: this is only for the rear calipers, the fronts are a much easier design with the metal ring. You will need compressed air and a nozzle you can seal against the brake line hole in the caliper. I definitely recommend regulating the pressure down (maybe 50 psi).
Take the rubber piston boot and insert it into the groove in the caliper (no piston). Insert and close the bleeder valve. Clamp the caliper in a vice or otherwise secure it so you don't drop it on your foot Apply a light coat of appropriate brake grease to the piston, especially around the bottom corner. With one hand, press the air nozzle against the brake line hole and seal it up. With the other, hold the bottom of the piston against the rubber piston boot. As you blow air into the caliper (SLOWLY!), the boot will expand out around the piston. You may need to jiggle and realign the piston so the seal goes on all the way around. At this point you can stop the air and slide the piston down into the caliper as you guide the inner lip of the boot into the groove on the piston. Voila!

Here's a tip for getting the pistons out of the caliper, works really well, especially if you're pistons are really stuck and rusty. No amount of air pressure will get a stuck piston out, it can be a real fight. BTDT...

Before opening any brake lines or draining any fluid out, go around and pull the pins and brake pads out of the calipers (leave the calipers mounted). Then just get in the truck and stomp on the brake pedal. The hydraulic pressure will force the pistons out. Stuck or not, they will all come out if you press hard enough. WOrks every time!

X2. I had to use this trick on both of my front calipers and one of the rears. Definitely works!

 

[Slomo]

Excellent idea, thanks for adding.

 

[AllenTenT]

fantastic ,,,,,,,thankyou

 

[Toyote]

someday i hope to contribute a technical post half this good. mud never ceases to amaze. until then, i guess i'm just a cheerleader. and not a hot one.

 

[treerootCO]

We just rebuilt the rear caliper on the Ptarmigan and replaced the other side with a new caliper from Toyota. I wanted to add to the FAQ that the brake pad design on an 80 allows the pads to fall out when basic preventative maintenance has been neglected. This results in the caliper clamping on the rotor until the piston is worn in half. Eventually the piston pops out and you lose all braking ability.

The 2nd thing that has been debated in length is what to lube the caliper pins with. I stand by Poser's advice to use anti-seize on the one that passes through the caliper without a rubber boot. This cavity is metal on metal. I used the pink stuff to lube the bolt that is inside the rubber boot. The failure mentioned above was caused by a bolt that had seized. PM aside, anti-seize would have helped.

 

[Slomo]

Good information to have, thanks. I have not had any problems with them yet in about 12k miles but I do not neglect my PM. I think the anti-sieze would work well and might indeed be a good option for those less inclined to keep an eye on things. Also good to warn of the possible consequences, glad that no one got hurt.

 

[rhyary]

To avoid the mess, and to have the ability to do it one corner at a time, I would like to unbolt the brake line and plug it well. So the master cylinder thinks that the caliber is still there. My goal is to eliminate as much brake fluid loss as possible.

I want to rebuild one corner at a time, and do the brake bleeding at the end.

Can you guys suggest a tried method to plug the brake hose either at the caliber side, or the frame side ?

Plan to do it this weekend.

 

[96r50]

Vise grips or proper line clamps. And just to state the obvious: don't drive it like this

 

[rhyary]

Squeezing the brake hose will not damage it?
I was thinking more like screwing the end into some kind of a cap.