Leave the seals in? brake caliper powder coating

djb25 · 08-06-2007, 08:33 PM

Hi everyone,

I'm about to embark on a front suspension pan replacement, and while I'm waiting for the new pan, etc. to arrive (whenever that will occur) I have been toying with the idea of powder coating my calipers.

The car's a '77 with cast iron calipers.

My question is - can I bake the calipers without removing the seals? The powder bakes at 350 degrees - I'm thinking it should be okay, because the brakes have to get above that temperature during heavy usage, right?

Anyone out there with any experience with this?

Thanks!

Damion

kcpaz · 08-06-2007, 08:39 PM

you won't be able to keep the powder off of the seals (unless your powder coater is good at masking and most aren't), besides, you should just rebuild the things while they are off and you have some down time. BTW, I would do high temp caliper paint, but that's just me

jpnovak · 08-07-2007, 03:53 AM

Yes, you can coat over the seals. The powder will not stick high temp, silicone based dust seals. Just make sure they are very clean. Some (including the factory) will coat over the bleed screws. I prefer to remove them and plug the hole.

btw, silicone dielectric grease makes a wonderful masking agent for complex surfaces where normal powder coating tapes do not stick or conform.

djb25 · 08-07-2007, 05:52 AM

That sounds about right... I wasn't really concerned about getting powder on the seals...

jpnovak · 08-07-2007, 05:56 AM

Another thing, If you are concerned about coating the dust seals. Leave the old ones in while you coat and cure. Then just swap out for the new ones. btw, make sure you have the piston all the way in. you don't want any powder to get on the outer circumference. It would likely interfere with proper operation.

KFC911 · 08-07-2007, 06:11 AM

Quote:

Originally Posted by kcpaz

.... BTW, I would do high temp caliper paint, but that's just me

Although I powder coated a bunch of my suspension, and had lots of stuff re-cadmium plated, I opted for the high temp paint sold here on Pelican for my calipers...they look fantastic and have held up great!

Early_S_Man · 08-07-2007, 06:50 AM

BTW, just in case you have the pistons and dust seals out for cleaning ... and were thinking of splitting the caliper halves, and were actually referring to the four fluid seals between the halves of the 'A' calipers, DON'T DO IT!

1. There aren't any replacement seals available!

2. You will mess up the Ribe fasteners if you try to use a Torx bit on them. Not the same bit at all, and Ribe bits are hard-to-find, since it is a European aerospace fastener that predated Torx by over 20 years !

3. No need to split the calipers if they aren't leaking, anyway!

bob deluke · bob deluke's Garage

Warren,

I have a 77 Targa with "M" style calipers I rebuilt. Porsche has rubber seal rings still available. P/N 90135192810. Damion didn't say which caliper he has. As a matter of fact, I bought 4 that I don't need. If anyone needs these seals that go between the caliper halves, let me know. I split my caliper easily with a Torx bit, but Warren is correct and be advised when he says use the proper tool. My calipers wern't all rusty and crapped up, came apart easily. Didn't rebuild because bore had a hairline crack, ergo, junk caliper. Hope this helps someone.

djb25 · 08-07-2007, 08:37 PM

These are the cast iron calipers - I think they're M calipers? I can never remember...

But no, I'm not splitting the halves. I haven't pulled the pistons out or anything. In fact, the calipers were brand new (NOS) installed in 2000. They work fine...

- Damion

Early_S_Man · 08-08-2007, 08:23 AM

The 'M' and smaller 'L' calipers use the seal Porsche part number 901.351.928.10 (same as VW pn 311.615.277) ... these will NOT work in an 'A' caliper -- too small!

The seal for the larger 3.5" ear 'A' calipers is not available!

Here are the proper Stahlwille and Hazet brand RIBE drive bits:

djb25 · 08-08-2007, 11:47 AM

Okay, actually I think the front calipers are "A" calipers and the rear calipers are "M" calipers.

They're all ATE cast iron calipers.

Perhaps the fact that the seal for the calipers is unavailable is the reason my front calipers were replaced rather than rebuilt...

- damion

BertBeagle · 08-08-2007, 05:54 PM

Quote:

Originally Posted by Early_S_Man

The 'M' and smaller 'L' calipers use the seal Porsche part number 901.351.928.10 (same as VW pn 311.615.277) ... these will NOT work in an 'A' caliper -- too small!

The seal for the larger 3.5" ear 'A' calipers is not available!

Here are the proper Stahlwille and Hazet brand RIBE drive bits:

A version of these (not Stahlwille or Hazet) are available at AutoZone. They are double ended and are driven with a socket or box end wrench. The same set has the one that fits the door striker assembly. About $15 for the set.