Finally figured out the dragging brakes problem. It was the o-ring pistons I installed a while back. I put the old pistons back in with new lipseals and they now work perfectly, no dragging.

TT

 

I don't like hearing that I was just getting ready to start buying them. I installed 2 on a car a couple years ago. Did you install the springs behind the pistons ?

 

I went to the SS calipers in 84. Probably put 30k miles in 20 years and the lip seals finally started to leak. I put the o-ring pistons in and that is when the trouble must have started. There were no springs for the o-ring pistons. I put the springs back in with the lip seal pistons. So far I've only restored the front from o-ring to lip seal. The back don't seem to drag like the front. Perhaps there was some clearance/tolerance issue that was exceeded or to tight. I'm just glad they work now.

 

you're the first one i've ever heard of that has had problems with o ring seals.


I'm not saying it's you. But it's you.

 

How much drag ? Can you turn the wheel by hand when its off the ground ?

Come on thats no way to look at it. There could be variances in piston manufactures and bore diameters. This might be worth noting and watching out for. I would like to know more. Bronz what are you going to do with the pistons ?

 

bronzebb,

Please remember that opinions are like steering wheels, everybody has one.
Happy Labor Day

 

I don't know the intent of Turtle's comments but I can perceive them a certain way. Hmmm, purpose, intent, perception, truth, opinion?

I could turn the tires by hand but it wasn't easy. I used some channel locks to pull the pads back and then the tires would spin freely. Now I can spin them by hand and they will continue to spin for a few rotations before stopping.

The pistons are on my work bench. Maybe the o-rings were too fat. Maybe the pistons were too big. Maybe the bore is too big/small. I should have mic'd the bores before I put them back but I'm not taking them apart to do it now. I can still mic the pistons. I would really like to know why I had this problem.

TT

 

Interesting problem.

I have VBP SS sleeved calipers that I installed in 1982. I was over at VBP a couple of years ago and mentioned how old my calipers were and they said if they ever started leaking to bring them in and they would rebuild them with O ring seals (or lips) for $35 each ( I think that was the cost - it wasn't much compared to what the kits alone would have cost) under the lifetime warranty. I'm guessing that the bore diameter specification is the same for each type seal and has never changed.

It is possible you got some out of spec O ring seals that were either too thick to begin with or the rubber composition was not right and the rubber O ring absorbed fluid or moisture and swelled. With the close tolerances in the bore a little swelling on the part of the O ring might be enough to have caused some binding.

Glad you got it sorted out and fixed.

 

I've been thinking about this and unless the pistons were binding (not the o rings) I don't think the o rings are the problem.
Also I'm wondering if the OP is expecting less drag than is normal.
"Several" rotations from a spin seams like too much to me.

 

Swelling o-rings could have been the problem. I had to pry the pistons out of the calipers with a screwdriver. They came out easy with a screwdriver but I couldn't pull them out with my fingers. There was some gunk in between the seal and the o-ring.

The pistons should always be square in the bores unless the pads really wear unevenly. My pad wear was perfectly even. It didn't look like the pistons were cocked when I took them apart.

With the lip seals I can spin the tires. You are right, they only spin maybe 1 1/2 revolutions. With the o-rings they were bound up and would not spin at all.

I have bigger problems now...I just blew the differential and had the car towed home. I am sick.

TT

 

Has anybody used o-ring calipers with hydroboost. I'm just not comfortable with the concept of o-rings , lip seals seem to be the hydraulic industry standard.

Sorry to hear about the diff. Driving her hard?

 

I have the orings with the hydroboost. So far after 3 years or so no problems at all.

 

F.Y.I. … I personally think the o-ring caliper is the only way to go. They seem to last forever and never leak or draw in air from cavitation. We sell around a zillion o-ring calipers a week and problems are just about unheard of.

The caliper bore (on ours) is always brought back to stock so the calipers can accept pistons and seals from any source.

The o-ring and lip seal pistons are almost identical – the only difference being the channel where the seal rides.

The pistons should be able to tilt or wobble a little inside the caliper bore. This (just like the lip seal) is to handle uneven pad wear, bearing and / or spindle runout that causes cavitation.

There should be some very mild brake drag when you turn the wheel by hand. It should be the same for an o-ring caliper and a lip seal one.

Attached are two drawings showing the difference between the o-ring and lip seal pistons. The lip seal reminds me of a windshield washer blade. It is very thin and will obviously wear out much faster than a solid rubber o-ring.

Hope this info helps …

Sincerely,
Alan G.
VBP - Vette Brakes & Products, Inc.


Cut-away view of VBP Lip-Seal Piston and Seal

Cut-away view of VBP O-Ring Piston and Seal

 

Not the first I have ever heard with problems, I like FACTORY ENGINEERING myself especially on stuff like brakes and suspension parts.

 

Been running the O-ringers w/ SS braided lines for 7 years with GREAT success and now been running the O-ringers/ SS braided linees with Hydroboost for 2 years with even greater success!!

To the OP, how old are your flex lines to the calipers? Maybe these are starting to collapse. Just a thought. Sounds like your luck is bad somewhere.

I did have to replace an O-ring seal set on my drivers front caliper this year as it started leaking after 7 years. I am thinking it was because I hit it pretty hard with my hydroboost when I first took the car out this spring while attempting to get my newly cut front coil springs to settle in after the front end disassembly for lowering purposes.

I would buy new SS flex lines and a O-ring seal rebuild kit ($60) and rebuild all your calipers, once your new lip seals start leaking on you.

Brent.

 

I replaced the master cylinder and installed new SS brake lines trying to chase down the problem. The calipers were Muskegon units purchased around 1984. They lasted a long time with the lip seals. Perhaps there are some slight differences in the bore finish as compared to VB&P.

The back brakes still have the o-rings. They work fine and do not drag (significantly).

The car is going to be parked for a while until I can see what is wrong with the rear. Probably the pumpkin guts.

TT

 

Do the calipers have a SS sleeve? What type of fluid.

 

So how did you notice this dragging problem ? Do you have a whole car dragging issue as in rolling to a stop and the car not free wheeling ?Are you sure your not blaming the o-rings when it might be caused by a little bit of everything ? There are many reason why a car will give you the no free roll feeling,one being the parking brake. Please give us more info as to why you were alerted to this dragging. Thanks