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Discussion Starter · #1 ·
So... i have been rebuilding my brake calipers and I have run into a problem. The rebuild kit that I bought from centerline did not come with the o-rings that go in between the two caliper halves (I split the halves because I needed to clean out the grease that I used to get the pistons pushed out). So the question is: WHERE CAN I GET THESE O-RINGS?

I've gone to about 10 car stores today and apparently these are nearly impossible to come by... any suggestions would be greatly appreciated because I have all the pistons back in and everything is ready to go minus putting the two caliper halves back together

Thanks guys
Andrew
 

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71 Berlina 74 GTV 17 Giulia Q4
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try
McMaster-Carr

great place to just browse around

I realize it's too late now but splitting them probably wasn't necessary to get the grease out. I used the grease fitting method and was very confident I got all the grease out of mine and my brakes work fine here 6 months later. Granted I used several methods to get the grease out but I'm sure I did.
oven heat, not to much
air
brake parts cleaner
more air,
repeat several times
 

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Give Andy Kress a call - he has brake rebuild kits ( you didn't say what car/brake calipers you have ) ATE for sure... IIRC....

Performatek - Home

508-655-8079
 

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You can go to a gasket supplier or hydralic seals supplier, and that place should be able to supply the correct size O ring and or seal for that caliper based on measurements only.
Good Luck
 

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You need to be careful on what you get though, I think these are square cut, not your traditional "o-ring".

Kevin
 

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Probably not an issue if you're buying from a brake parts supplier, but be careful that the O-rings you get are compatible with brake fluid. Researching the net recently for another O-ring in the brake system, I've found that most materials that O-rings are made from, even those meant for hydraulics, aren't recommended for use with brake fluid.
 

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I had the same issue after splitting my calipers for re-plating. Those seals seem to be hard to find at least in this part of the world, so I had them custom made at local rubber-product shop.

As far as I know the material should be EPDM or similar to resist brake fluid - it seems to be much naughtier stuff than motor oil.
 

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71 Berlina 74 GTV 17 Giulia Q4
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"it seems to be much naughtier stuff than motor oil." if you've ever gotten any in your eye you will definitly know that is true.
 

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Been there, done that. The square section "O" rings are impossible to source, or at least I could not find them. Was concerned about using ""round" section "O" rings but I got a fair amount of feedback from people saying the "round" section ones caused no problems. Also, you have to make sure you use "O" rings suitable for use with brake fluid. Most "O" rings are not suitable for use with brake fluid
 

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caliper O-rings

I went through all this when i put together the spacer kit for the dedion rear calipers - to go with the vented rear rotors.
theses O-rings need to be resistant to brake fluid, elevated temperature (actually a pretty broad temp range for most rubbers), square sectioned and of course of the proper dimensions. I spent a lot of time identifying materials, vendors etc, and as far as i could find, no one made the proper part as a stock offering. ATE was of no help.
Consequently, i had them custom made.
I don't list them as a separate part on my website (performatek.com)
however if you email me: [email protected] (or call me at 508-655-8079) we can work something out.
andy
 

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caliper o-rings

A few years ago when I was rebuilding a set of rear Spider calipers to replace the sticking ones on my 86 Graduate I was in need of these o-rings. The replacement calipers were bound up tight. The old o-rings might have worked but the condition of these calipers was really rough. I had soaked them in the ultrasonic bath at work with a strong concentration of Alcanox or Alconox. A strong, alkaline I believe, laboratory detergent. It took everything off, paint, dirt, rust, everything. But the pistons were still stuck.

DANGER, do not do this at home, or at work

Not knowing about the grease gun trick at the time I used compressed air, a scrap of wood to prevent the piston from coming all the way out, and a 55 gallon drum for a blast shield. I was expecting a lot of liquid and crap to shoot out when the piston came out. All was set in place in the bottom of the drum and the air was turned up from a distance, until a violent separation of piston and caliper occurred. The piston was now jammed between the wood and the opening. The wood should have been just a little bit thicker. It could not be made to go back in without splitting the caliper to release the piston from the new trap it was in. I also still had to get the other piston out.

I was given a source, probably here or the Alfa-Digest, that the correct size o-ring was available over the parts counter at one of the German car dealerships, Porshe, BMW, or VW. I forget which one but am leaning toward VW for some reason. Of course, I have no recollection of year and model. Not much help here today. And it is unlikely the counter person will know it from sight, but worth a try.

For me it did not matter as midway through I discovered the calipers I was rebuilded were from a 1600 not a 2000 car so work was abandoned.

Go here for a list of o-ring material compatibility.

eFunda: O-Ring Materials Compatibile with Chemical Brake Fluid

keep in mind also the temperature range your caliper operates in.

Good Luck,
Wayne
 

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You should be able to re-use them. If they dont work, you will find out when you bleed the brakes before you get on the road.
 

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Discussion Starter · #16 ·
hey guys

thanks for all the words of wisdom. I think I'm going to try and re-use the old seals seeing as the difficulties in finding new ones. I'm definitely going to check on the calipers for the first couple drives after I get them installed to make sure there are no leaks. If there are I'll try and order some new seals from the website in the second post (they seem to have an incredible inventory).

Cheers
Andrew
 
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