1986 GT, Automatic, 62K miles, stock drivetrain and brakes.

I just discovered that the driver's side rear caliper has a class II leak. Do I need to replace calipers in pairs? Do I need to replace the pads? Do I need to have the rotor turned (resurfaced)?

Thanks,

Jonathan

At that mileage if I were to be doing the brakes and they are for sure the original rotors, then yes I would have them properly turned.

You can measure the pad thickness with a tire depth gauge. I usually measure it in three places across the "face" of the pad. This can tell you a lot, such as if a caliper is dragging and/or potentially causing uneven pad wear. Measure both pads on one wheel and also compare it from one side of the car to the other, so you can see how the caliper is working in relation to the pads. Use your own judgement here on if you need new brake pads or not.

Going off of the above; Do you have to replace both calipers? Well, no, you don't have to. Should you potentially replace them both? I typically do. Again, tell tale signs of pad wear can dictate potential caliper issues without them even leaking. To be safe and if it were my car I would replace them both.

[This message has been edited by Fiero84Freak (edited 02-13-2013).]

Class II leak? I take its really leaking. You can change just the one, its quite a chore to do. Why double the aggravation lol. See if you can get a "loaded" one
(pads included) The old ones most likely are contaminated with brake fluid. And while all is off have the rotor turned. Its the going back together and getting the parking brake set right that will cause of harsh language.

I wanted to save money too, thought I'd only buy one caliper, would up just chasing my tail around the whole car, eventually putting all 4 new ones on it. Always do them in a L/R pair. Same with shocks/struts, and tires.

I have replaced calipers individually, depending on the condition of the other calipers. Turn rotor? I would only do this if there was a problem with the current one. The problem is finding a shop that will turn them anymore

Most times I just buy new rotors. Places around here charge almost as much to just turn them. I always replace things like calipers, tires, shocks, etc in pairs (both sides). You could have problems with one side pulling harder/better than the other. I will replace only one tire if they are all in good shape and only blew one out.

quote Originally posted by jaskispyder: Turn rotor? I would only do this if there was a problem with the current one. The problem is finding a shop that will turn them anymore

O'Reilly will turn rotors.

Jonathan

quote Originally posted by Boostdreamer: O'Reilly will turn rotors. Jonathan

3+ hour drive for me

JFI

Place here charges $10-$15 each to turn a rotor. I bought 4 new OEM rotors and pads for all 4 wheels online for $55 for my Mercedes SL.

Theres got to be somebody in Kingsport that still turns rotors. My small shop near home still does. Chain stores just want to sell product.
Id spend the dollars on a turn than want to pull a Fiero rear caliper on and off for that. The Fieros rear brakes were designed by a panel of sadist's lol
At least you dont have a class III and a wheel fire...they suck with plastic cars!!

Bill

quote Originally posted by rogergarrison: Place here charges $10-$15 each to turn a rotor. I bought 4 new OEM rotors and pads for all 4 wheels online for $55 for my Mercedes SL.

I think O'Reilly charges $10 per rotor. I had no idea they could be bought so cheaply. I'll check on that before I do anythng!

Thanks for the tip!

Jonathan

Most time one is bad then other is failing too.
If Pistons are good (very rarely) then seal kit might help.

Get rebuild and hope there good ones...

Turning Fiero rotor? Sometimes. Rotor Spec in my cave...

See my Cave, brake section.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

hey do vary quite a bit by car. Ones for my Astro were $12 each, Corvette was $50 each.

quote Originally posted by rogergarrison: hey do vary quite a bit by car. Ones for my Astro were $12 each, Corvette was $50 each.

Rock auto prices... $13 to $60, depending on quality and front or rear.
fyi

quote Originally posted by jaskispyder: Rock auto prices... $13 to $60, depending on quality and front or rear. fyi

Yeah, locally, they're higher. About $30 a piece. The good news is that my rotors look pretty good. I'm just going to keep them as they are. I did the fingernail test and there were no grooves big enough to catch it on.

Next question: Can I use anti-seize on the bleeders? Will that in any way contaminate the brake fluid or cause other harm?

Jonathan

I put my new calipers on and they leak worse than the originals. They are leaking from the hose-to-caliper connection. The Haynes manual says that bolt is 15 foot pounds. I've backed it off and re-torqued it several times. The latest time, I bumped it up to 17 foot pounds. I'm afraid of stripping the threads in the aluminum caliper body. What can I do? Is this a matter of flat washers vs the original "ringed" washers?'

Any help? This has already turned into a three-day event.

Jonathan

I was going to suggest making sure you could open the bleeders on the other calipers before replacing them, but you have already replaced the other side. On the washers, I've found most of the time the leak is at the line (block) surface, which is ridged and the ridged washers don't seal right. It was a good idea to replace the other rear caliper. GMs rear caliper pistons pit badly and are getting expensive to replace. The front uses phenolic pistons and you can normally rebuild.
It is also very important to adjust the caliper piston out by using the E brake or E brake lever before moving the piston out by applying the pedal.
The ratchet assembly, in the caliper piston, needs to be within a certain amount to work correctly or will never adjust out properly. If you have already moved them out by pedal, push the pistons back in as best as you can and used the E brake or levers.
You can use antiseize, but it has to be at the threads outwards and a very small amount. Inside the thread area can contaminate the fluid.

Bump -

quote Originally posted by Boostdreamer: I put my new calipers on and they leak worse than the originals. They are leaking from the hose-to-caliper connection. The Haynes manual says that bolt is 15 foot pounds. I've backed it off and re-torqued it several times. The latest time, I bumped it up to 17 foot pounds. I'm afraid of stripping the threads in the aluminum caliper body. What can I do? Is this a matter of flat washers vs the original "ringed" washers?' Any help? This has already turned into a three-day event. Jonathan

quote Originally posted by Boostdreamer: I put my new calipers on and they leak worse than the originals. They are leaking from the hose-to-caliper connection. The Haynes manual says that bolt is 15 foot pounds. I've backed it off and re-torqued it several times. The latest time, I bumped it up to 17 foot pounds. I'm afraid of stripping the threads in the aluminum caliper body. What can I do? Is this a matter of flat washers vs the original "ringed" washers?' Any help? This has already turned into a three-day event. Jonathan

Here is what I do. Take the caliper surface, where the banjo bolt is and sand it down (take care to keep filings out of hole). Make the surface smooth, as it is probably bead blasted and not machined like the original.

Then take your washers, if not using new, and sand them down. Now bolt it back together. If need be, I will gently tap on the banjo bolt with a brass hammer to help set the copper washers if I still have problems. Just light taps... probably not needed.

This has worked multiple times for me. The surfaces should be machined, but with rebuilds (I assume you are using) they are not machined (usually).

[This message has been edited by jaskispyder (edited 02-18-2013).]

I'll give it a try. Thanks!

Jonathan

The copper washers are crush washers. Get new copper washers to seal properly.

quote Originally posted by smartaxel: The copper washers are crush washers. Get new copper washers to seal properly.

Actually, the old washers seal better than the new ones. After I stripped one new caliper with too much torque, I put the old one back on with the old washers. It is dry as a bone. My new one, even after the hammer trick, is still leaking. My next step is to take it back off and try to file the surface down. If that doesn't work, someone mentioned using ALUMINUM washers. I have to try that.

If none of that works, I'll just put the original caliper back on. It was leaking less than the new one is now!

Jonathan

Yup, I found the new crush washers don't work as well as the original. Annoying.

Heating probably would be a bad idea... but what if you heated the copper washers, then quickly installed?

[This message has been edited by jaskispyder (edited 02-19-2013).]

I did the hammer trick and at least it is leaking more slowly. I'll check it when I get home. I HAVE NOT pulled it off to try to file down the surface of the caliper yet. That will be my next step. I think I'm going to have to "Brake" down and do it!

Jonathan

Yeah, filing/sanding down the caliper surface was the best solution for me. Too many irregularities on the caliper surface, and you can't torque the bolts down enough to crush the washer properly, to mate.

Just got home and there's a puddle under the caliper. It's got to come off. I'll go to Home Depot and buy some aluminum washers tonight, too.

Jonathan

You don't need to remove the caliper from the car, just disconnect the line, sand down the surface.

quote Originally posted by jaskispyder: You don't need to remove the caliper from the car, just disconnect the line, sand down the surface.

I didn't take any chances. I pulled it from the car, used my grinder on it then a half-round file then 400 grit sandpaper. It is VERY smooth. I hooked it up last night and there are no drips this morning! Looks like I'll have my car back this afternoon!

Jonathan

congrats!

The original calipers were machined on the section where the brake hose bolts up. These new ones had a cast surface just like the rest of the caliper body. There is no way that surface will seal anything as it is. Especially when you step on the brake pedal and put the fluid under pressure!

I tried hammering on the bolt before smoothing down the mounting area. That didn't work. On the other side, I tried only making the surface smooth but not hammering. That didn't work either. I had to do both on each side. Now it's working.

Here's the new caliper after I worked on it. You can see a little bit of the reflection of the green plug. I could have made it look like a mirror but 400 grit is fine enough for this job.



Jonathan

I am guessing who ever rebuilds them just sand blasts them. The problem is that they are aluminum... also, there is corrosion to deal with. I wished they machined the bolt mounting area.