While swapping back to street brake pads from my race pads, these rings fell out from my OEM Brembo calipers. The calipers were rebuilt by a local company at the start of the season.

1. I'm guessing that the rings are part of the dust boots that cooked off? If not what are they?

2. What is your opinion on running without them?

No fluid is leaking out and the brakes seem to be performing just fine..

 

Here is a picture of the rebuild kit for Brembo calipers:


What has happened is you've melted your dust boot. The pistons may not be leaking now but what will end up happening is dirt and water will get into there and scratch/rust your bores/pistons, resulting in new calipers as you won't be able to rebuild the old set...

I suggest you get them rebuilt ASAP to stop any more damage from happening.

 

ugh.. it's always something. The company who rebuilt them must have used cheap parts.. The boots were crumbling after their first track day.. and this after the second. I shouldn't expect to have to rebuild my calipers after every track day... My non-brembo calipers lasted about a dozen track days with no need to rebuild.

I was hoping that it wouldn't be a big deal since other calipers (like wilwood) don't even come with dust boots (if I recall correctly.. i could be wrong).

Thanks for the info. I guess the Z will be down for a while until I get this done.

in the meantime - any other opinions?

 

The outer dust boots are often 'cooked' when used for track day, high heat runs. Quite common and I don't know of any brand that doesn't have this problem. While it may expose the piston shell to more dirt and grime and possibly lead to further problems of contamination (only really when you retract the piston) running without them is not a big deal. The square cut o-rings are not exposed to the same temperatures and seldom of the same material even so they'll hold up fine.

The potential problem is the contamination and potential pitting of the piston which then gets drug back into the seal causing damage as well as the potential to more quickly dry out the seal than you'd have if the boots were in place.

 

I don't know about all of the brands, but the current AP Racing calipers have highest temperature seals/boots they've ever had. It's the same "rubber" as racing seals were made of just a few years ago. They put up with quite a bit of abuse from what I've seen. And, even higher temp seals are available for the very few who might need those.

For the factory Brembo's or even 370Z Sport Akebono's, no such option exists that I'm aware of. You might want to just keep extra sets on hand and change as required. Both of those setups have temperature limits that are short of what is required for heavy track use. Titanium shims might extend the change interval a bit, if you are willing to pay for those.

Regardless, I don't believe it is a real good idea to run without boots or secondary dust seals for daily street driving. Some will get away with it and others will pay the price. A lot depends on where you live, what climates you experience and whether or not the roads are salted in your area. The safe bet is to run them, taking a close look after every track day.

Chris

 

We offer silicone dust boots that are better suited to high temperatures which are standard on all of our current kits. Our dust boots should be a direct fit for your Brembos. While i cant guarantee they wont burn up, they will hold up much better than standard rubber parts. The dust boots are sacrificial however so you should not expect them to last forever.

If you want to reduce heat transfer into the dust boots and the rest of the caliper, you may also want to look into Ti plates which act as a heat shield.

 

Thanks for the replies everyone. I'll be ordering some seal-kits... and maybe some shims too.

 

One piston of the four would freely pop out with the compressed air. I was able to get the others to extract themselves enough to get the boots off (1/4" - 1/2") but damn.. those suckers will not come out.

Can I use channel locks or some sort of wrench to pull on the outside portion of the piston to remove them? I know you don't want to damage the pistons - but is this mainly for the portion that slides in and out of the cylinder and not the part that touches the brake pad?

The damn pistons seem seized in there..

EDIT - Nevermind. I put the new parts into the one cylinder that I could, then secured the piston inside with a clamp.. then was able to use the compressed air again to get two others out.. now will have to secure 3 while extracting the last stubborn piston.

 

If you can, re-insert the loose piston and push them all back in their bores. Then put a stack of 1/2" plywood blocks in the caliper that is about 3x thicker than the rotor. When you hit it with air again, all four pistons will extend to meet up with the wood stack. Remove one piece of plywood from the middle and hit it with air again. Repeat until you hear the pop of the first piston releasing. Now, the other three pistons are nearly at the end of their travel and can be wiggled out by hand.

Now to get that last piston separately, you will need to cut the plywood blocks in half on one side, leaving one piston without opposition. One piston pair will lock on the wood stack and the 3rd piston will be held in place by the blocks that weren't cut. The 4th piston should be free to extend if you gave it enough space.

The good thing about using wood is that you won't tear up the caliper like clamps can easily do if/when they slip.

Chris

 

Thanks a lot for the explanation. In a way, I'm thankful that my calipers are all beat up - so I don't really care about the paint. The clamps worked out well.. but if I ever get them powder coated I'll use the plywood method.

Thanks again!

 

Ahhh....I see Chris, Eric (?) and I will all be offering tidbits of information!

Seems you have three folks in the biz with differing opinions on things from a different perspective. None really right or wrong mind you but each one valid.

And btw; yes I'd agree that heavy road grime/salt/crap would benefit from a booted caliper. But then I've also generally considered one who partakes in track day activities on a regular basis to be more conscience of maintenance also making it less of an issue.


Eric; you send me some guy the other day about a Toyota project? (thanks) Not sure what he's really dealing with and if he's really wanting to take on a custom build.....low volume production stuff just never turns into that "oh yea, I have one of those" deals.