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Those might work. I know the CSSB Inc. ones work. Unless they moved, they'll ship from near Miami.
For my other car, I bought mine from Zip when they were on sale. They were specifically original Delco Moraine castings, rebuilt by Lonestar with O-rings. Perhaps you can find a better deal that checks all of the boxes.
Perhaps other folks have used the new Delco castings. I haven't, so I can't say if they will work. Perhaps they are stainless sleeved right out of the box. It might be a good question for Zip or one of the other vendors. If they don't have stainless sleeves, even if they work today, you'll be in the same spot in 5-10 years when the cast bores corrode.
I'm going to go against the crowd here bc I've taken apart a lot of calipers over the years and put them back into service (that lasted years). What you have is pretty normal gunk inside old calipers that don't get driven a lot and have moisture in the fluid. If they were mine, ...and I was in the UK, I'd pull off the lip seals (gently), clean off the pistons with some steel wool, hone out the bores with your thumb (and some 600 grit wet/dry paper) and put them back together. The scores in the bores isn't un-normal. They'll hone out nice. Like I say, just use your thumb or make a diy drum with sandpaper on it. Check the run-out on your rotors. They might be out-of-spec looking at those scores.
Then, if you want to order a re-build kit w/pistons you can rebuild yours with new parts. They're a lot lighter to ship than a whole caliper. Bear in mind some of the cheaper seals aren't all that great (IMO). So buy a good kit.
Mark G,,,, I second that. I use a regular hone, with a drill and 600 grit sandpaper to dress up the caliper bore. A good seal kit and you are good. Just be careful NOT to scratch the NEW seals.
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I would reuse the calipers too. Clean them up. Inspect the pistons for any pitting where the lip seals make contact in the piston groove. That is where the seal is made but pitting elsewhere on the piston is irrelevant unless it will make contact with the bore. If so, file it smooth. If the lip seals have expanded, buy a set of lip seals and put it all back together. Just trying to save you some money.
The reason I say, "Check the run-out on that rotor" is bc too much run-out on C3 rotors causes the pistons to vasillate in/out as you drive down the road. This is a phenomena of C2/C3 disc brakes that doesn't occur on other vehicle's brakes bc GM used Lip seals on C2.C3's (it was GM's first time at bat on disc brakes, and lip seals were kind of a foul ball of an attempt). As the pistons go in/out rapidly due to a slightly warped rotor, due to being 'lip' they tend to 'pump' air into the calipers. Eventually (or sometimes within a test drive), it results in spongy pedal or even a near total loss of brakes. The Rotors really need to be as close to .000" as possible, although .002" would be as far as most would recommend as the limit. No surprise the caliper on that rotor felt 'funny' ..could be because the rotor is 'out of spec' sucked in a lot of air (in that caliper) making it 'seem' like it's not braking well, or pulling. When the real culprit might be the rotor (check it).
Now ...the question you ask is ...why would the rotors be warped? Ahhh good question. History lesson: Because GM did a real quick machining on the front hubs, riveted the rotors onto the hubs, then turned (resurfaced) the rotors while ON THE HUB. That was great on the factory expensive equipment bc they could achieve a run-out of near-zero doing it that way. And the lip seals wouldn't be an issue. BUT ...but ... lol. several years down the road joe blow takes it to get new brakes and the shop says 'you gotta replace your rotors' or he does the brakes himself and slaps on new rotors out of the box onto a hub that was never machined 'true'. Therefore the rotors will never be true unless they are machined to by rotating the hub (which few shops have the equipment to do). I see one of your rotors has been replaced. I would definitely check that rotor. Just to give you an example, both hubs on my 81 measured .006" and .008" run-out at the HUB FACE! With a rotor installed, it would be amplifiied to .013" out of 'true'. I bought a couple used original hubs off ebay and they measured .005 & .006 as well. I finally made a jig to resurface them absolutely 'true'. I wasn't in a hurry, but if I was counting my time, I would have been better off buying brand new properly machined hubs.
GM quickly saw the error of their ways and went to a square-cut o-ring inside a machined groove (inside the bore) with a stainless or chrome-plated (or phenolic) piston ...which essentially is how they have been ever since. But going to o-rings on movable pistons in a C3 isn't a perfect solution either. That's another debate. Lip seals are fine and work great ..the real solution is to make sure your rotors are as close to .000 as possible and periodically during periods of non-use, go out and press the brakes a couple times to exercise the lip seals. Or buy aftermarket (re-designed) calipers which DO have an o-ring in the bore (and non corrosive piston), essentially a modern designed caliper. But either way, you need to have 'true' rotors. If you don't have an inexpensive dial indicator and magnetic base, it would be a good thing to get/borrow and check your car's rotors. Bc even if you DO get your calipers good again, 'true' rotors are a must. https://www.ebay.com/itm/383477161951
I agree, I would absolutely rebuild that caliper. But I can get 3 more cores at Carlisle if I need to. Before he tears apart the rest of the car, he may only have two rebuildable calipers (SS sleeved OEM Delco Moraines) and they aren't even a matched set. So I answered the question @Last Triumph asked as best I could, which was where to source replacement calipers, with a future (cheap shipping) rebuild in mind.
I agree, I would absolutely rebuild that caliper. But I can get 3 more cores at Carlisle if I need to. Before he tears apart the rest of the car, he may only have two rebuildable calipers (SS sleeved OEM Delco Moraines) and they aren't even a matched set. So I answered the question @Last Triumph asked as best I could, which was where to source replacement calipers, with a future (cheap shipping) rebuild in mind.
Yep. At the price for rebuilt caliper in the UK (per a poster's example) ...it might make sense to consider Wilwood calipers done right. But if the OP can get what he has back on the road for now, he's got some time to come up with a replacement strategy. One might be to purchase 'good' cores locally (facebook?). My hunch is that rotor might not be in 'spec' which is another matter to be resolved if it is. But the other side rotor was still riveted on as I recall. Ahhhh ...aren't brakes fun!!! LOL
Yes, in theory a rebuild on that calliper alone with a hone and o-ring kit is the 'answer', subject to what I find on the other front rotor, as if there are shenanigans going on in therms of pad to rotor mating survace etc, i then need a replacement front calliper as the generic one is not a rebuildable core, and that's when here in the UK it gets tricky, which given how close the cost becomes between Delco and Wilwood, makes the Wilwood option attractive as it's lighter and easier to bleed and I'm sure some other fringe benefits. Noting however I'm an originality guy at heart making it a tougher choice.
Next step is to look at the front right and see what's going on there.
Rotors are pretty much brand new, but I'll check run-out with my dial gauge.
I've got my '81 pretty much dialled in now, except the brakes.
They pull to the right under anything more than medium braking. The harder I brake, the more they pull.
I've just bled them completely all round but no change.
They do not leak. (EDIT: Some or all of the part about them not leaking may not be completely true)
Rotors all good, pads all good, no judder, squeal, wobble etc, just a pull to the right beyond medium braking force.
The two callipers on the left appear to be original (car has 42k original miles)...
However the two on the right have been replaced with generic remans...
I have a few questions.
Is it possible to tell (without stripping) if my original callipers have ever been rebuilt, and if so whether they have stainless liners and or O-rings? If so, how?
If they are original, could it be they are just not performing as per the new ones, hence pulling to the right, i.e the new ones are performing correctly, but the left (front?) isn't up to much beyond medium duty?
What is the best way to tackle this - from the UK where Corvette bits, especially heavy parts like brakes are very expensive due to international shipping, duty etc.
It might be a moot point but for the record, when bleeding them, the front left did not bleed as freely as the other three using gravity bleeding - the fluid came out very slowly where the other corners dripped freely and quickly, where fluid from the front left crept down the pipe very slowly.
I would just buy new quality front calipers.. I installed new caliber’s and one of them were defective and had the same thing you have. Good luck
Checked out the other calliper and pad/rotor interface and its all good so for now I'm just rebuilding the current one with o-ring seals, new pistons etc.
Quick question, is 600 grit a sufficiently fine texture to leave on the stainless bores, or so I need to go finer?
I've got all the grades up to 7,000 and have 000 grade steel wool so can take it as far as required, where is the sweet spot?
All the advice I've found online suggests using a brake caliper hone. Mine cleaned up with brake cleaner, so if I touched them up with anything more abrasive than a microfiber towel, I don't recall it.
I used 600 grit on NON sleeved calipers and seemed to get a very smooth surface, but finer would be good. I even installed O-ring seals on the non sleeved calipers and they work fine.
All the advice I've found online suggests using a brake caliper hone. Mine cleaned up with brake cleaner, so if I touched them up with anything more abrasive than a microfiber towel, I don't recall it.
600 is certainly not fine enough, though.
Originally Posted by kodpkd
I used 600 grit on NON sleeved calipers and seemed to get a very smooth surface, but finer would be good. I even installed O-ring seals on the non sleeved calipers and they work fine.
Thanks both.
I've looked at a brake hone tools and do wonder what grit stones are in them and what equivalent finish they would leave - I suspect not much finer than 600?
I have that same tool..... I use fine sandpaper around the stones to go finer. The stones are not that fine. As the 600 paper wears down it gets finer.
I have that same tool..... I use fine sandpaper around the stones to go finer. The stones are not that fine. As the 600 paper wears down it gets finer.
Suspected as much.
So if I finished off with 1,000 grit wet n dry, I'm good?
