rdupler2

I am doing brake maintenance on my '72 350/200 Auto Coupe.

I have the SS sleeved calipers, however, I found that the pistons have the lip-ring seals instead of the O-rings. Upon considering conversion to the O-ring type, it appears from the pictures on all the parts websites that the pistons that come with the O-ring conversion kits are not metal but some kind of plastic (at least they look like it because they are all black and not metal colored).

Questions:

1. Are the O-ring type pistons indeed some type of plastic and if so how durable are they? The existing pistons in my calipers appear to be aluminum.
2. What has been the experience of others who have converted from lip- ring seals to O-ring seals?

Thanks so much in advance.

Regards,
Roger

fugawi

i've gone to o-ring calipers about 6 years ago, and would not go back. no worries of air pumping into calipers. if it's not for an ncrs correct car i would go with o-ring calipers..

v2racing

I went with the o-rings also. No problem at all. The brakes always work and never leak. The pistons are still aluminum but are black anodized, at least mine were.

Manuel Azevedo

If one does use the "O ring" do you remove the springs also?

wcsinx

You can. They don't even matter with o-ring pistons because they have much more pressure in the bore than lip pistons, and those springs are flimsy as hell. I tried it for myself before I put my calipers back on. I put a spring in, coated the bore with brake fluid, then pushed the piston all the way down. The next morning, the piston had not noticeably moved. Soooo f'k it, out they came.

The most plausible theory I've heard as to why the springs are still included in o-ring rebuild kits is that they put them there just so people would stop bitching about them missing.

Manuel Azevedo

Thanks

This was not intended to Hijack this post either!

rdupler2

That's Ok Manuel, I never would have even though to ask that question. Very interesting.

Duane4238

A lot of good info on the O-ring conversion. Just wondering where do you get the O-ring kits?

wcsinx

Vette Brakes and Parts

http://www.vbandp.com/detail.aspx?ID=830

$160 for the full kit, just be sure you have SS sleeved caliper bores first

Clams Canino

Everyone I know agrees that O-ring seals are superior.
And I've heard repeatedly not bother even using the springs with O-rings.

-W

Ganey

I have rebuilt the SS sleeved calipers w/ factory lip seals. Switched to VB&P aluminum O-Ring pistons. Springs did not come w/ caliper kit.
Fast to install.

Manuel
Yes, remove springs.

0grandmastercorvette

I have mentioned this on other posts that deal with this same question....because the post was "O" ring vs. lip seal"

The "O" rings were put in ...not to make them "superior"....but ...rather to make it so the issues in the bearing and rotor run-out not to have to be so "dialed-in" as GM required for using the lip style seals. If your bearing and rotor run-outs are very slightly out of spec. Then using the "O" ring style MAY be for you. I myself...would advise correcting the problem...that caused the caliper issues. I ...professionally speaking...CAN NOT sell the "O" ring design....due to legal issues that COULD arise from changing from factory design. Until official documentation dealing with the testing of the "o" ring installed calipers has proven to be an EQUAL or BETTER than the lip style seals...than I will be on board with you all. BUT only until then.

The lip seal is designed so that when pressure is applied to the pedal. That pressure pushed against the back edge of the lip seal...causing it to seal tighter when more pressure is applied. That is what the lip is for. The "O" ring does not have that capability...and that is where I draw the line.

And before you guys get on a bashing session.....I have NOT heard of any failures to the "O" ring designed calipers that caused a fatality...BUT I have had many "O" ring style calipers that leaked and needed to be changed...which was due to the run-outs were way out....along with not keeping up on changing the brake fluid due to moisture contamination...thus causing "grit" to get in between the sleeve and the "O" ring and erroding away the sleeve....because the run-outs were to great and causing the piston to move in and out more than it should have .

If you guys love them...and are not having any problems...THAT'S GREAT!!! BUT if you do or did have a problem with them...please be decent enough to let those on the forum know...so others can make sure that they have areas checked...because the "O" ring are not a "fix-all" when run-outs are not correct.

The springs installed in the calipers AID in keeping the piston from cocking and binding with the cylinder bore...that is why it is located in the center of the piston.....along with applying a very small amount of pressure to the piston to also keep them so when the brake pedal is pressed...the pistons are even...and will make the pad contact the rotor equally...thus making it so your pads do not wear out unevenly. This also depends on how well the pads are able to slide in the guide pin. Do with them as you wish...but they are there for a reason. And yes...I have seen problems with them in calipers with the lip seals...so I am not going after the "O" ring style here. But this is often times contributed to some "BUBBA" siliconing the piston to the backing plate of the brake pad....which I DO NOT advise. BUT once again...its your car...your brakes...your life...do as you wish.

Its guys like you who have them that ...with photo's and mileage since installed...will allow me to see if it truely is worth changing to... So I welcome any imput. But this would involve a tear down and inspection. So if you have a leak...please inform us who NEED to know this stuff. And if all of you have NO problems...well...my hats off to you. I will possibly have to make a decision...in the future on this. Because my luck....if I install a set.....I will be the ONE that has a problem and end up losing my shop.
"DUB"

jb78L-82

Just a counter point, I have had SS lip seal calipers on my car since 1985, change the fluid every 2-3 years, and NEVER had a leak. I read DUB's comments very closely. I am not so sure that I would switch to an O ring seal if I did have a leak-probably just buy another lip seal to fix the problem.

rdupler2

Dub, thank you for the candidness of your posting. You have made some VERY good points and I appreciate it. I had decided to go with the O-ring seals (before I read your post) only after consulting a number of long time users who swear by them. I hope I haven't made a mistake as I purchased them earlier today.

Regards,
Roger

JD McC

Duntov Motor's site has a pretty good explanation of the o-ring -vs- lip seals that would seem to support DUB's post.
http://www.duntovmotors.com/CaliperSchool.htm
It will likely be next summer before I get to my brakes so I will be watching for any new info on this debate.
JD

turtlevette

There is just too much time involved in constantly checking the runout on these things and correcting. If i replace a rotor at the track i sure don't have time to sit there and play with it for 2 hours to get it dialed in. We need calipers that can deal with some wabble. But i understand if you make 100s of thousands working on these crap brake systems and rear bearing abortions and are very happy about it. If people make them better, your business dries up.

VBP sells the O-ring calipers as extreme duty calipers. Do you know more about it than them?



You are wrong. If you take a close look at a piston designed for O-rings, the seat for the O-ring is beveled so that the piston moving towards the pad causes an expansion of the O-ring against the bore to seal tighter. The wedge effect. Take a look and get back with me.


Before WE? get on a bashing session. What are you doing? There have been plenty of fatalities using the lip seal design. Buford Pussor's brand new 74 vette's brakes failed and killed him.

All lip seals leak. Lip seals are paper thin and don't stand up to heat well. Do 6 threshold brakings in a row from 100mph and get back with me. Runout with lip seals cause air pumping and you have no brakes at all.


That is not true. The piston centers based on its seating against the pad. The springs will not center the piston when you have pad taper.. The springs keep the pistons from backing too far away from the pad. The stock design provides almost no resistance to piston knock back. The O-ring desing provides significantly more resistance to piston knock back. They fit much tighter in the bore.



I don't think that is silicone you are seeing. It's anti squeel coating that provides a dampening effect for the pad to prevent brake squeel.



Take some time and search through the archives. See how many people complain about spongy brakes, marginal brakes and no brakes. See how many have swapped over to O-rings and see a huge improvement. There's literally hundreds of threads about this. Where have you been? The better solution is to go with a wilwood or other modern caliper such as a C5, C6 or Brembo, but i guess that's too radical for you to consider because its a change from the 50 year old design.

I'm surprised you're still not selling buggy whips. Well maybe you are.

MN-Brent

I have this combo:

Hydraboost - SS braided flex hoses - VBP O-ring seals conversion kit on SS sleeved calipers - OEM FF grade brake pads - OEM style calipers - Valvoline DOT3/DOT4 fluid.

Took 7 years before the O-ring kit started leaking, but it did in one of the front calipers. I think it may have been the higher pressure the hydraboost unit applied to the seal in the early spring when I was out reseating my front coils after I cut them down to lower over the winter. I was working the brakes to get the front end to nose down at maybe 10MPH.

Other than that, its been flawless. With all that, O-ringer are the way to go with OEM iron calipers.

Clams Canino

Actually that site is fudging the graph a bit to make thier point stand out more.
Both the lip type and O-ring seals pretty much are still "constant contact" as they don't retract away from the rotor at all. So the graph is comparing apples and hammers.

And Dub only said he can't/won't install O-ring calipers because the closer he stays to OEM - the less liability he's exposed to. He's not knocking the O-ring design.

-W

rdupler2

Wow, I didn't anticipate such a lively discussion on this. Everything I have read seems to lean heavily towards the O-ring design.

Someone has told me that depending on the shop that installed the SS sleeves, when they machined the bore larger to install the SS sleeve they left some bores with a "step" at the bottom of the bore. This step was not ever an issue with original pistons but is with the new style O-ring pistons as these pistons are a bit longer and sit deeper into the bore.

I have only taken the right caliper apart so far. Looks like I may have an issue as the sleeves don't go all the way down. In fact looking at the ones on the first caliper, each one is slightly different. Can't say yet that they won't work but I would have to try all of them to see. Hmmm, if one does not work then I wouldn't want to have a hybrid system. It's either convert all of them or none of them. Bummer.

WESCH

Hi

I had air pumping on my aft brakes with the lip seals, but absolutely no visible leak. Also the bearing play or disc runout was still very minor.
Lost aft brakes completly after 200 Miles, bleeding them brought them back just to loose them again after 200 Miles.

The O-ring kit solved this problem.

I had leaking O-rings after 6 years , driving 40.000 miles. The brake was never lost, just leaking slightly showing this on the rims.

That's the difference to me. Lip seals don't even need to show leaks to loose the brake. O-rings show leaks , but keep the brake operational.

Looks also like that if you use DOT4 fluid , that the brakes start leaking earlier. Use DOT 3 , some swaer on this.

Rgds. Günther