Corbrastang

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Bluestripe67

It may be relative to who did the rebuild. Dennis

53 Blue Flame

I've only had positive experiences with the O-ring type calipers. Never anything to complain about...yet.

Tampa Jerry

I put them on my 68 and 66. I also installed a set on a friends 70. Easy install, no problems. Jerry

RestoDoc

O-ring calipers ( New castings ) are all I'm installing in my shop. I'm tired of the banged up, leaking rebuilt original cores that cause us to have to change them out after they failed the power bleed step.

I've never (knocking wood) had a problem with the new O-ring calipers.

Tintin

We used O-Ring pistons on the PBR calipers when I raced Camaros in Firehawk years ago and they are somewhat sensitive to being overheated. The o-rings will become brittle and need replacement. It is also critical not to let dirt or water get behind the o-ring on the piston. We rebuilt the calipers after every race but they should be ok on the street for a couple of years at least...

The o-rings are easy to replace - put a piece of 1X4 in the caliper and hit the pedal. The pistons will come out far enough to get the rings off and new ones on...

Bluestripe67

RestoDoc, You might want to fill out your profile, it's too your advantage. Dennis

gbvette62

There were some sealing preoblems with some early refitted O-ring calipers. Some manufacturers calipers O-rings had a mold line on the outer edge of the o-ring, causing a weak spot. That's the only negative I've ever heard attributed to the O-ring calipers. A leaking O-ring shouldn't cause a caliper to stick, though. Have you replaced the rear hoses? Old hoses tend to collapse, causing a caliper to lock up.

65 vette dude

I replaced all 4 of my lip seal calipers with the oring type,and no problems. They came from Lone Star.

obx2323

I Have VBP O ring calipers all the way around zero problems. Stops on a dime and gives you 9 cents change back..!! Even went with the red powder coated. Great company service too BTW.

I also went to a dual master as the previous owner suffered a failure with the old style and almost bought the farm. 1st thing I changed.

uncle427

Hi,
You do not say if you installed the o-ring pistons into calipers you already had, presumably with the lip seal pistons. You do not indicate if its the rears that are sticking.

I will assume you installed the pistons and its the rears sticking.

Many of the calipers out there rebuilt or new designed and built originally for lip seals use a shorter piston. During machining there was a minimum depth required for the sleeve in the bore. It only needed to allow the lip seal piston design to fully retract flush with the casting. Also during machining for the sleeve the new bore sometimes was not concentric with the original bore, that created an off center "step' at the bottom of the bore.

Early original castings had a guide pin in center which lead up into the center off pistons, this design will only work with original design pistons with the insulators installed on them Unless the boss is machined out.

None of the above created any problems at all using the intended lip seal piston.

But, if now you install the newer design (and superior) o-ring caliper piston it can be an interference problem, the o-ring piston sits deeper in the bore and will potentially bind and **** the piston as the bottom of the piston jams on the step at the bottom of the bore.

Its not a big deal to fix but you need to be aware of it beforehand. Before installing your pistons, check the bore and the piston fit (without the o-ring on it) to be sure it will go to the bottom of the bore, not **** and still be free. If not, just take your dremel and grind the step, it will not take much to correct.

Some suppliers such as Vette Brakes used to give you a bulletin with the kits with a warning about this but if you buy kits supplied by a jobber supplier, there is no literature at all.

Every ones o-ring pistons will have the same potential issue so its not who you buy them from

BTW, the early problems with o-ring calipers were for sure associated with regular o rings (as stated previously, caliper pistons are custom mold with an offset mold parting line, NEVER use regular o-rings), there was also millions of calipers manufactured offshore and will have no delco markings which were a big problem due to the castings being porous, lots of them.. , so o-ring calipers got a bad rap early on.

If you are not racing on the track, the o-ring calipers properly built are the only way to go!

Let us know what you find.
Bill

MikeM

A master cylinder piston that does not return fully will also cause the brakes to stick.

The first step is to find out which wheel(s) is/are dragging.

Corbrastang

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uncle427

Be sure you did not put the springs behind the o-ring calipers, they are unnecessary.

Be sure the master cylinder piston is fully retracting past the vent hole in the bottom of the resevior. You should be able to see that thru clean fluid. If you cannot, the vent hole may be blocked from crud.

If the piston is not, either the push rod is out of adjustment holding it from fully returning or maybe other linkage issue. This condition will not allow the residual fluid pressure to bled off and will keep the system locked, temperature increase will lock it harder.

Be certain the e-brake is adjusted properly with the adjusters on the correct sides, check the diagram for orientation, I always need to double check.

Bill

JohnZ

How old are your rubber flex hoses?

Corbrastang

All the hoses and brake lines are new.

MikeM

Drive the car for awhile and then stop and feel the wheel in the area of the wheel center. If you feel more heat on one than the rest, that's a place to start. If all the wheels seem like they're warmer than you would think, I'd be looking at the master cylinder system. If all the wheels are cool to the touch, I'd drive on.