Rear Caliper Lip Seal vs. O ring

[Greg W.]

After pulling and sending off the trailing arm, I noticed one of the caliper pistons leaking brake fluid. Does anyone have any thoughts on replacing the lip seal with the new O-rings they sell? Pros/Cons? Appreciate your feedback. They are original calipers, if it makes a difference. Thanks,

[Bill L.]

Re: Rear Caliper Lip Seal vs. O ring

My '66 Big Block Coupe with original calipers and lip-seals had the seals replaced in 2000..... I drove the car at least once per month every year since with no problems --- now in 2015... I had "one" (1) lip-seal caliper fail on the right front --- replaced both left and right seals at the same time with lip-seals --- no issues --- probably last another 15 years ---

I "think" the key with lip-seals is to drive the car --- (novel idea I know---) that way you don't have problems--- here in Georgia we pretty much have a 300+++ day driving season --- so it has never been an issue.

I have however, heard good things about the "O" ring system ---

You might want to contact Mike Zamora in the NM Chapter --- he has the best info on the "O" rings ---

Regards
Bill

[Joe L.]

Re: Rear Caliper Lip Seal vs. O ring

I'll repeat something here I've said before. O-ring caliper piston technology was available at the time that GM designed the first-for-1965 Corvette disc brake system. Other major caliper manufacturers used it. So, why did GM use the lip seal for Corvette? There had to have been a good reason.

[Greg W.]

Re: Rear Caliper Lip Seal vs. O ring

Joe , As Bill stated his have lasted 15 years and mine 20 years. If not for the trailing arm out I would have not known. That being said I do not drive the car a lot (not by design) and would one last longer than the other. I may as well do both sides as I have to bleed the left side as it stands. If I stay with the lip seal all I need is the seal kit. Who knows if the o ring would last as long. Anyone know if new lip seals can be installed without using a seal compressor tool as the manual states. Thanks again

[Gene M.]

Re: Rear Caliper Lip Seal vs. O ring

I just installed O ring seals on one of my stubborn leaker cars. The lip seals replaced were not of USA manufacture. Try to find USA made parts is getting to be a joke. Well, anyway time will tell if the O rings are any better. I did polish finish the cylinder bores to 3 micron finish as recommended. Dot 5 fluid was used.

[Steve G.]

Re: Rear Caliper Lip Seal vs. O ring

I'll repeat something here I've said before. O-ring caliper piston technology was available at the time that GM designed the first-for-1965 Corvette disc brake system. Other major caliper manufacturers used it. So, why did GM use the lip seal for Corvette? There had to have been a good reason.

That's right Joe. And all of the floating pistons calipers of that era that I've ever come across all had lip seals while all the floating calipers
systems that I've ever seen all had square cross section o-rings.

I've always been of the understanding that it had to do with brake release and pad drag, but I don't know that for certain.

Steve

[Michael G.]

Re: Rear Caliper Lip Seal vs. O ring

I've dealt with many lip seal failures over the years. Four years ago when building my '66 convertible made the decision to change over to O ring pistons and Dot 5 brake fluid. Four years later no brake piston failure and a nice solid petal. Now, I'm not going to state that O ring is better than lip seal pistons.....what will I say.....four years later and still leak free.

[Gene M.]

Re: Rear Caliper Lip Seal vs. O ring

I've dealt with many lip seal failures over the years. Four years ago when building my '66 convertible made the decision to change over to O ring pistons and Dot 5 brake fluid. Four years later no brake piston failure and a nice solid petal. Now, I'm not going to state that O ring is better than lip seal pistons.....what will I say.....four years later and still leak free.

I'm glad to hear that. A least 4 years of not doing brakes is encouraging. Both lip seals and o rings require a clean smooth bore. A hone and polish should insure no leaks, knock on wood.