When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I had leaky caliper a year ago. The replacement went well with no issues. Since then I've been working on a few more things and I had to take the caliper off again. This time it didn't go back on quite so easy. The springs kept pushing the pistons back out and I struggled getting the caliper over the rotor. I think this was because the second time I had fluid in the caliper. The pistons got sideways on me, fluid was spilled. A true newbie mess. Now the caliper is leaking.
Here is a picture of the caliper.
The rubber seals you can see don't always stay in the right spot. I think this is just a dust cover boot, so I don't think that's the end of the world.
I think the actual fluid seal is another O-Ring underneath that I can't see without taking the whole thing apart. Is that what is damaged? Is the only way to fix it to tear the whole thing apart and replace the seal? I am going to attempt a warranty replacement, but I'm worried that I caused the damage.
The odd thing to me is when I push the pistons in now, one side seems to stay in while the other wants to pop back out because of the spring. That seems weird to me, but no experience with 4-piston calipers before so I'm not sure.
I think the pistons are getting wonky because the pads are not in, to guide them.
If you have a woodworking saw, cut / rip two wooden sticks about 8" long.
Stick A. Will be 1 1/2 x the rotor thickness + 1/4"
Stick B. Will be 1 1/2 x the rotor thickness minus 1/4".
On your workbench:
Install your pads.
Open bleeder.
Insert narrower stick B.
Using compressed air and nozzle, force air into brakeline port. Note how the pistons react. Ok?
Remove stick and insert thicker A. This will help you install the loaded caliper on the rotor. As soon as the bolt holes line up somewhat, pull the spacer out.
Last edited by HeadsU.P.; Jan 31, 2021 at 01:26 PM.
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
If you bought the caliper from your local parts store it came with 'lip' seals and when the piston went 'sideways' it runed the seal.
Just tell the parts person it leaks and they will give you a warranty replacement.
Use the pad to push each side down squarely and put a 1 1/4 socket between the pads and slip the caliper over the rotor.
There is a caliper tool you can buy from Corvette vendors that is not very expensive. It is a "U" shaped clip that fits over the pistons so the caliper slips easily over the rotor.
I bought the caliper piston compressors. Didn't really work that well. I made a block of wood to keep the 4 pistons far enough apart to slide the brake disk in. I think the outside seals might have backed out a bit. They can dislodge if the pistons push them out. They are only held in by friction. Try tapping them in so they are flush. If they don't stay in, you probably need new ones.
Another brake question from a newbie
