How to remove Caliper seals to inspect bore?

[Peter B.]

Hey Everyone,

My rear caliper is leaking. I took it out and found that it is not sleeved, but looks very new (or VERY well painted to look new with new looking seals).

I want to remove a seal to see if the bore is pitted (will need to change for sleeved calipers) or if it is just the fact that from sitting for a LONG time, there is a leak & can just be rebuilt.

Any tips on how to remove that press-fit dust shield without damaging the caliper?

Thanks

[William C.]

Re: How to remove Caliper seals to inspect bore?

A suggeation, just move on to sleeved calipers. If you remove the dust seal, it will need to be replaced with a new one, and from experience, rebuilds are temporary while a well-done sleeve is a permanent solution.

[Jim T.]

Re: How to remove Caliper seals to inspect bore?

Peter how can you tell that your brake caliper has not been sleeved with stainless steel if you have not yet removed the the leaking calipers dust seal?I don't know how each stainless steel sleeved caliper rebuilder identifies their work, but I believe Vette Brakes and Stainless Steel stamp each caliper to "brand their product".

[Joe C.]

Re: How to remove Caliper seals to inspect bore?

Pete:

Agree with Bill, but your calipers may be sleeved and still be leaking due to "gunk" and corrosion in the piston seal lands (grooves). This is why it is important to replace all 16 pistons. To remove the dust seal (and this will destroy it.....but you were gonna replace them anyway, right?), lay your screwdriver across the piston, push the piston fully into the bore, then insert the end of the screwdriver under the seal and push down on the other end. This will pry the seal off.

Some rebuilders stamp the caliper with their logo if they have been rebuilt (and sleeved) by them. For instance, Vette Brakes will stamp in a "VB". Look for any such marking on the calipers.

[Joe L.]

Re: How to remove Caliper seals to inspect bore?

Peter-----

If the calipers are painted silver or a silver-like color, then you can be pretty well assured that they've been sleeved. Most caliper rebuilders paint the calipers this color. I don't know of a single rebuilder that rebuilds these calipers without sleeving them, even if the bores are perfect (and they VERY rarely are perfect in the original condition).

[Peter B.]

Re: How to remove Caliper seals to inspect bore?

You guys were right. I took off the seals (without damaging them) and they are sleeved calipers. However, WOW!!!!!!!!!!! The amount of Gunk I found was AMAZING. I mean AMAZING. It was like Jelly Brake Fluid. I cannot believe it.

I cleaned out one of the bores with steel wool and it is perfect. I had to scrape off the gunk from the piston and use the steel wook on the metal part of the piston. Looks back to normal.

HOWEVER, I can only imagine that the entire brake system is the same. I guess I will bleed out this line first before re-installing the caliper. Bleed this caliper and then do the same to all the others. Lets see if I can get away with not damaging the seals and if the other calipers have not been damaged by the Gunk.

Thanks

[Peter B.]

Re: Tell me more about this Silicone thing

I was also reading that I should put a bead of silicone in the groove that the piston dust cover sits in. Is this silicone lubricant or silicone sealer (RTV)????

[Dick W.]

Re: How to remove Caliper seals to inspect bore?

Even properly sleeved calipers will leak sometimes. Trash in the bores, normal aging, etc. All it takes is a good rebuild kit.

As for the "gunk" that has accumulated in the caliper, rest assured the rest of the system has the same crap in it. If my feeble memory serves me correct either the owners manual or the service manual references flushing the brake fluid once a year. Remember, mineral based brake fluid is hydroscopic, that is, has an affinity for moisture. Silicone will not mix with water, but it has it's own problems, aereation, traps moisture in pockets (remember, water corrodes steel brake lines) etc.

The best bet is to flush the system regularly. This would have saved many a caliper over the last 39 years.

[Patrick H.]

Re: How to remove Caliper seals to inspect bore?

Peter,

You "may" get lucky enough that you only have to replace the seals on one caliper. Check your local auto parts stores, as they can likely order in the seal kit for one. Then, replace seals and flush and flush and flush. Then flush every two years to avoid the Jelly Fluid Syndrome.

Patrick

[Jim T.]

Re: Tell me more about this Silicone thing

Peter GM came out in the later model years to use silicone sealer when installing new dust seals.
With the "gunk" you found in the caliper, what you could of found was the result of someone changing from conventionl brake fluid to silicone brake fluid and not flushing the conventional fluid throughly from the system. Do you have silicone brake fluid in your 71?

[Peter B.]

Re: Tell me more about this Silicone thing

Not sure, but I just bought 2 quarts of it and will now.

[Peter B.]

Re: How to remove Caliper seals to inspect bore?

Patrick,

Thanks

I did not have silicone on the dust shields. I found that out from the leaking one. Do you recommend I put the silicone on the rest? If so, I may just end up getting the gunk out. I do not rest well knowing that there may be gunk in there.

However, if you feel just flushing will take care of it, I will just do that.

What do you think?

Thanks

[Patrick H.]

Re: How to remove Caliper seals to inspect bore?

Peter,

If you're worried, then take them all apart. Will flushing get rid of all the gunk? Well, can't guarantee it...

If you're going to take them all apart, get new kits from Vette Brakes to make them all into O-ring calipers. In addition, get stainless bleeders or Speed Bleeders if you wish. Install the dust seals with high temp silicone as noted.

If you're going to have them all apart, then paint them flat to semi gloss black as original while you're there anyway. Pick up some VHT caliper paint from AutoZone.

Then, you will have stainless sleeved, O-ring calipers with stainless bleeders in the correct appearing color. Just flush the system every 2 years and never have a problem again.

Mine don't leak, but this whole process is on my "to-do" list. I've got all the parts, but....

Oh, also check out the price difference between getting 4 calipers in black already O-ringed vs buying the parts from Vette Brakes and doing it yourself. You mayy find you save a lot of time and effort having them do the work even if you don't get as much $ for your core charge.

Patrick

[Patrick H.]

Re: Tell me more about this Silicone thing

Peter,

Read the Archives regarding the proper procedure in converting from "regular" to silicone brake fluid. They don't mix!!!

Patrick

[Joe C.]

Re: Tell me more about this Silicone thing

Peter:

I recommend installing new seals, and they will come with a green or orange sealant already applied to the contact surface. If you insist on re using your old seals, then MAKE SURE that the mating surfaces are clean, and use Loctite "sleeve sealer" on the mating sufaces.

Joe