Caliper makeup

[Transam388]

I am going to replace a caliper this weekend and was thinking of powder coating it instead of just brush or spray paint. The powder coating though requires you bake the piece at 400 for 30 minutes to cure the powder. Anyway, this brings me to my question. Does anyone know if any of the internal makeup of the caliper has anything that would get messed up by heating it to 400 for 30 minutes? Granted the piston boots have to come of and then back on once done but anything else to worry about.? Also is putting those boots back on around the pistons a PITA? Thanks ya'll!!

[Steve Crowe]

The piston seals and boots are all you have to worry about and yes - the pistons are near impossible to put back in because of how tight the seals are.

While you've got them apart you may as well replace the seals & boots if you can find a couple of kits nearby. I've rebuilt quite a few LS1 dual piston calipers, they're made by PBR if I recall. You can usually re-use the boots that cover the caliper bracket pins but be darn sure to grease them well with caliper lube before assembly.

Another thing to watch for, the pins get worn over time allowing a fair amount of play in the direction they get pressure. You can usually turn them about 90* and get a better fit.

http://www.iecoklahoma.com

[silent101]

I was also thinking of geting my calipers powder coated as well. You are saying that the piston seals are imposible to get back on? How much do new ones cost?

[Steve Crowe]

Not impossible, just nearly so without the equivalent of a piston ring compressor for that size. One little nich and you're in trouble.

I highly recommend using real automotive Urethane basecoat/clearcoat paint for calipers. You can have any paint store mix you up a quart of DuPont Nason color to exactly match or compliment your factory paint job then you end up with a beautiuful yet tough finish which puts up with about anything.

If anyone is interested I'll do a writeup on the details when I get a chance.

[silent101]

Ya I just wanted to know if you could poudercoat them because I have heard that pouder coating is by far the toughest paint. Why would'nt the brakes hold up to 400 for 30 min when they get very hot when there on the car. On some cars I have seen them red hot and that has to be hotter than 400.

[Steve Crowe]

The big LS1 calipers don't really get very hot, even under heavy usage. Regardless, it's not a good idea to heat anything made of rubber, nitrile or whatever - especially when it's under pressure as it can deform and remember - you depend on your brakes.

These brake fluid boiling points will give you some idea of what a caliper experiences internally:

<PRE>
PROPERTY DOT 3 DOT 4 DOT 5
Dry BP (F)@ 0.0% H2O 401 446 509
Wet BP (F)@ 3.7% H2O 284 311 356
</PRE>