My front passenger side brake caliper seems to be sticking/binding on my 1980. I have not had a chance to examine it properly, but I was wondering about my options. If it is binding, is it probably beyond repair, and should I get new calipers for both sides? Or, will a repair kit be enough, to re-condition the calipers? Kinda pee'd off that this is happening. I have only done 3000kms since the calipers were replaced. Whichever option I go for, I will do both sides.
Any suggestions?

Thanks.

.....Mike.....

 

How old are the brake lines? It could be internally collapsed...

 

I think the first suspect should be the rubber hose from the frame to the caliper. Swelling inside can inhibit the return of the fluid to allow the pistons to "relax".
The only way I'd recommend rebuilding or replacing the caliper is if it's leaking or if the fluid inside has jelled when you try to bleed it.

 

Quote:

Originally Posted by SEVNT6

How old are the brake lines? It could be internally collapsed...

Interesting theory Guys. Thanks for your comments. I don’t know if the lines were replaced when the calipers were done last time. Last week when I drove the car, there was a burning smell and today, the passenger side front wheel was really hot to touch after a short drive. But there is no leak. So binding seems to be the problem, but I never considered the idea that a collapsed line might be responsible. The car feels dangerous right now. It pulls violently to the left when I brake, and then when I try to correct it, it pulls to the right!!!! Obviously, I will not be driving it until I resolve this. I will get out there tomorrow morning and see if the lines are intact or not. I am located in Ireland, so getting parts is a bit of a pain, and it can be expensive too. I hope this is a simple brake line issue as you both suggest. I’ll take a look in the morning, and report back.

Thanks Guys.

…..Mike…..

 

Ha ha.... good luck! Rarely the hose breaks down and doesn't let fluid go back. That's a 1 in 100 chance..... Worth a look, but. C3 calipers corrode due to not exchanging fluid enough, and moisture and old fluid attacking aluminum pistons. Therein lies the problem -- the bores filling up with aluminum crud deposits, and pistons getting jammed in place. I bet that's what you find. Let us know. Fortunately C3 calipers are easy to field service/clean. You may want to look at it before getting the replacement. Maybe the build-up isn't too bad and you can clean out & put them back into service in an hour?? It's worth a look. IMO, the best way to go is to look at it first and if it's bad, order one from OReilley Auto. They sell Lone Star calipers and you don't have to pay shipping like online places might make you, and they have a lifetime warranty. Plus there've been guys who've had to dicker and argue (usually with minimal results) to get warranty issues taken care of by online sellers. I mean, shipping a caliper is heavy...and C3 calipers are rife with leaks!! Go to OReilly auto and avoid all that.

If you want to look at the caliper first, Jack the car up and feel the wheel bearing. There should be a slight amount of back/fourth play. Then rotate it and if it's still binding, remove the wheel. First look at the brake pad pins and where the pads slide. Are those surfaces worn where it's causing the pads to not back off?? If not, you might as well retract the pistons (with a screwdriver or something) and pull off the caliper. Before you remove the caliper, figure out a piece of small rubber or wood cone or something you can ram into the end of the hose fitting once you unscrew it...to keep the fluid from leaking out. Or otherwise have a catch can/pan handy if you want to let it run out anyway.

Then split the caliper in half. If you don't have an impact wrench, ...plan ahead: before you remove the caliper from the car, break those two large caliper bolts 'free' so you can split the halves once you have it off the car. Take the caliper apart on a bench. Fluid will leak out, that's ok but be prepared. Carefully use the dull or rounded corner of a gasket scraper and lift up the dust seals. You can almost always get them all off w/o damaging them (in case you reuse the parts). Remove them. Then remove the pistons. Clean and inspect the pistons and seals and the stainless bores. Probably there will be some fluting in the SS sleeves. A guy can smooth out the fluting even honing by thumb, or making an instrument with some fine wet/dry sandpaper and oil.

At that point, if it looks gawd awful in there, and if the pistons are real corroded, you need to imagine the rest of the calipers are probably the same way. You can rebuild them and that's quite a bit of work. If you're handy and like to do things for the sake of doing/learning, then its definitely kind of a fun job. It's not difficult, just methodical and you won't save much money by the time you buy the parts...and for sure if you consider your time. And you might not be able to do as good of a job depending on the fluting and/or your skill level. If you just want to get on with things and enjoy the car, look at the other calipers and/or consider replacing them all. Or you might take the opposite caliper off/apart and see what it looks like inside. Most likely they could all be in some state of bad condition.

But.......say the pistons don't look too bad, say, some corrosion but they look good around the lip seal area, then clean them off and a guy could put them back together and get another couple yrs out of it. And be on his way. I would glue a dot of wet/dry 180 grit sandpaper onto the tip of a 3/8" dowel (in a drill) ...and with some oil 'machine' the o-ring mating surfaces so they're nice and smooth. Caliper rebuild places usually sandblast calipers and they don't machine a nice surface in the o-ring area. I would do that. You might drop the o-ring into boiling water to get it to return to shape better if you need to. If you clean/machine the caliper o-ring surface you eliminate one of the most common leak issues ...so you won't have to deal with that.

Basically that's it. If the hoses look suspect, order a new one/s. A lot of guys are going to chime in it's broken-down hoses, but like i say, it's a slim chance that's the only problem. Pad binding and/or internal corrosion (crap inside the bores) are the most common problems. And if you want an OEM quality hose you need to get ones from like an online brake place. The GM ones are thinner and the ends 'look' slightly different ...although they will work just fine. Ultimately a guy should bleed the brakes and get new fluid in every few years otherwise they get moisture in and corrode like what's happened to your calipers. It's easy to overlook and put off (I'm guilty of it too)...it's the nature of owning a corvette.

Best of luck. Let us know what you find and what you do.

 

Wow, Mark G. You have painted a picture that I was afraid of, initially. I am pee’d off about this because I moved from Canada to Ireland 5 years ago. Before I left Canada, I had the brakes serviced, among other things. The guy said that he replaced the front calipers because they were not matching. But I knew that years before that, I had all four calipers replaced with pricey SS-sleeved calipers. Shortly after I moved to Ireland, I was thinking how that last service guy could claim that the calipers didn’t match. Then I remembered; I had painted ONE of them blue to see if it looked cool. But you couldn’t see it at all through the stock wheel. So I didn’t bother to paint the opposite caliper. This guy must have looked at them, and assumed that they were mis-matched because they were a different color!!!! He probably installed cheap, non-SS calipers which are now causing problems. Meanwhile, my SS calipers on the rears are perfectly fine, even though they are much older. Anyway, I will examine it all in the morning and see what I can find. It is after 7pm here now and it is getting dark.

Thanks for your input, Mark.

…..Mike…..

 

Whoops I didn't see you lived in Ireland. Jeeez, I didn't know anyone was using non SS sleeved calipers anymore.

Well, then in your case, take it apart like I outlined and see what you have. Maybe the bores are just fine and can be honed. You can hone them with a shorty hone, and get a micro-polish by making your own micro-polish hone. I just took a sanding drum (or was it a round piece of wood on a metal dowel)...and put some foam on the drum and wrapped some fine wet/dry sandpaper around it. The foam added pressure. Use oil of course.

Maybe your pistons are good enough. Maybe your seals and everything are good and can be reused after a good cleaning? Maybe it ACTUALLY is the hose? All worth checking. Ask around, Maybe there's a parts store in the UK that can get C3 rebuild calipers from a warehouse reasonably priced. Calipers are real heavy and shipping would be a killer for you I would think.

Otherwise, if you're a decent mechanic, the calipers are easy to redo. Not all kits (quality) are created equal..

The root issue with C3 calipers is GM used lip seals attached to spring-loaded aluminum pistons. WOW..that was a mouthfull...think of all those things nobody ever did again. Lip seals (pumps air like a Jellyfish moves!), Seals on pistons, not a square o-ring in a bore groove. Aluminum pistons that can easily corrode. And spring loaded (hello jellyfish!!..ha ha). But when everything works 'right' they work great. I think the design was great for like a race car and that's where (in Zora's mind) where it eminated from. The calipers in my Hummer H3 look almost exactly the C3 calipers (w/o the lip seals or spring loaded AL pistons).

Hey do they pronounce it al-u-MIN-eum there??

Take them apart and see what you have. Let us know. Don't sweat it, you'll get them working again soon.

 

Time to pull them apart. Have the calipers been serviced in the past? Were they sleeved in stainless steel? When were the rubber hoses changed? Corroded hoses can act like a check valve and trap brake fluid in the caliper resulting in a stuck or sticky caliper. I have repaired mine and a few for other cars. This becomes more of a problem if the car is not driven regularly. If the calipers have been sleeved in the past, after thorough cleaning using denatured alcohol, consider replacing the pistons with O-rings style and new seals. The kits are about $150 to $175 for all four wheels. If you are not worried about originality, replace the brake lines with stainless steel shielded teflon lines. Rebuilt calipers from some vendors and auto pars stores may not be Delco Moraine castings, but from "off shore" sources. I have rebuilt many calipers, and the O-ring kits are much easier to install than the original lip seal kits. Good luck. Jerry

 

You wouldn't be able to see a compromised inner hose surface from the outside – unless it's so bad it has developed a swelled bubble in the outer casing. Would you post a pic of the hose where the metal is crimped on?

 

Well, everything LOOKS ok to the naked eye. The flex line seems to be perfectly fine. There is no sign of any leakage at all from anywhere. I guess I’m gonna have to take the caliper off and take it apart. I didn’t want to do that if I could avoid it. But I think I have little choice.

 

I have to disagree. It happens quite often with older cars.
Outward looks won't reveal what's going on inside the hose. Just crack the bleeder screw and see if the brakes release.
The best fix though is to replace hoses and calipers, both sides, front and rear with parts from CSSBinc.

 

Ironically, the wheel spins with no restriction at all. I presume the pistons slowly relaxed as everything cooled down after yesterday's short drive. I'm reluctant to do much more myself. I have never opened a caliper or rebuilt one. When it comes to brakes, I am a little scared of them, really. I mean if they are not 100% right, you can end up in serious trouble. I don't want to ever experience my brake pedal going down to the floor with no stopping power! I think I will talk to my mechanic tomorrow - the guy who works on my daily driver.

.....Mike.....

 

Mine did the same thing...after I replaced the collapsed right front line that looked fine..

 

That hose appears to have a single crimp which is the way the factory hoses appear. Only hoses with double crimps have been available for decades (?). I'd say they are original or at least very, very old. Wipe off the road dirt and see what the date code says. The hoses are like tires, they have a limited life and are recommended to be changed every ~10-12 years.

That looks like a relatively new caliper and certainly not original. An original by this point would be quite crusty with surface rusting. I'd wager they are not in need of rebuilding or replacing if you don't see any seepage at the joints where the two halves bolt together or at the piston seals on the backside of the pads. Once the new hoses are installed (yes, all 4 corners), do a full brake flush and bleed.

BTW, to remove the rubber hose, the end at the frame needs to be disconnected before the end at the caliper. After the new hoses are installed, check to be sure there is no twist of the hose any more than 1/4 from end to end. The white stripe, lettering, or ribs help to determine the twist.

Here's a pic of a modern hose with the double crimps:

 

Anyone know what the deal is with the spring-looking things inside the disc vents?

 

I had this same problem on my '68. It was the hoses.

 

Catastrophic failure is extremely uncommon, however, it can happen with old hoses that suddenly burst or pull out of the fitting. (Do you get the sense that I think you should change the hoses? )

Working on Corvette brakes is a simple, though often frustrating, job that many non-mechanical owners tackle as a first task. The greatest failure that happens is that something leaks or they cannot get the system bled adequately. You would know that problems exist before any sudden driving failure.

 

Quote:

Originally Posted by 67:72

That hose appears to have a single crimp which is the way the factory hoses appear. Only hoses with double crimps have been available for decades (?). I'd say they are original or at least very, very old. Wipe off the road dirt and see what the date code says.

The calipers were replaced 5 years ago by a mechanic I was never satisfied with. So I would assume that he didn’t replace the flexible lines at that time. I have done just over 3,000kms since then, which is less than 2,000 miles. You are all giving me encouragement to replace the lines anyway, and see what happens then. Maybe I will.....

​​​​​​​.....Mike.....

 

That is encouraging.
.....Mike.....

 

Hmmmm, this is encouraging!

.....Mike.....