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  #1  
Old April 16th 2008, 15:58
Clatter Clatter is offline
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Powder coating calipers

Why couldn't the seals/pistons be left in place during powder-coat?

The seals are going to be hi-temp material, as brakes get really hot during heavy use, right?

powder coat ovens are 350F or so? Anybody know?
Do brakes get hotter than that?

So, not to have to spend a sack of money on the rebuilt kits (944T),
why not leave it all together and powder-coat?

If all of the passages were plugged, and the seals never got sandblasted...

Why Not?
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  #2  
Old April 16th 2008, 17:38
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matara matara is offline
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Strip and Paint

Have a look at this method of repainting calipers:-

http://www.skylinesaustralia.com/for...b-t206478.html

Cheers

Steve
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  #3  
Old April 16th 2008, 19:05
Clatter Clatter is offline
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Was thinking that powder coat would be more durable.
Rattle-can always seems to be a real temporary thing.
Seems that if you masked the seals and pistons really well with duct tape during blasting,
the powder wouldn't stick to the rubber anyway.

The seals would survive the oven OK, maybe?
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  #4  
Old April 16th 2008, 22:14
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wrenchnride247 wrenchnride247 is offline
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The calipers must be stripped of all coating, washed, and dried. Then, they must be heated to 400 deg. for about 40 min or so to "burn off" anything that could contaminate the powder. Next you coat'em and put them back in the oven for 30 minutes after "flowout" (the change from powder to liquid) has started. Just keep in mind, DOT 3 brake fluid boils at around 400deg. (dry) and 284deg. (wet) "dry" means no water in fluid, and "wet" has 3% or more moisture present in fluid. Since these are used calipers, they will have moisture present in fluid. The only way to completely remove the fluid is to remove the pistons, and flush all passages. If you are careful and put all pistons and seals back were they came out of, you MIGHT be OK. This should help you decide what to do.
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans

1962 SC 1776cc SP 944NA brakes, 993 wheels

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  #5  
Old April 16th 2008, 23:18
Bullyboy Bullyboy is offline
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the brake fluid would contaminate the powder and you would have a bubbly mess.
Do it right the first time



brake machining by VDub Engineering
powder by me

Last edited by Bullyboy; April 16th 2008 at 23:21.
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  #6  
Old April 17th 2008, 11:26
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wrenchnride247 wrenchnride247 is offline
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Those look nice Bully. That a metallic I see? Clatter is wanting to do the 4 piston brembo's, WAY more costly than your ATE sliders. I've done both...(at work, can't upload pix) They are posted in the brake forum anyway.
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans

1962 SC 1776cc SP 944NA brakes, 993 wheels

VKG
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  #7  
Old April 17th 2008, 11:34
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gonebuggy gonebuggy is offline
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Quote:
Originally Posted by wrenchnride247 View Post
Those look nice Bully. That a metallic I see? Clatter is wanting to do the 4 piston brembo's, WAY more costly than your ATE sliders. I've done both...(at work, can't upload pix) They are posted in the brake forum anyway.
What makes the Brembos more costly to coat? Surface area? or does the paint know the difference in their pedigree? lol

Alex
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  #8  
Old April 17th 2008, 15:23
Clatter Clatter is offline
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I'm trying to get around the $800 penalty for replacing the seals.

The pistons were pretty 'extended' due to the car they came off of had worn pads.

Then, they were very carefully scraped clean using dentist tools, scotch-brite, and brake cleaner.

Next comes the paint remover, then seperate the halves and finish the cleaning.

Thinking that i could push the pistons back in, and mask w/duct tape for blasting.
(All of the fitting holes would be plugged).
Flush out all of the old fluid from the cylinders using the brake-clean and the long tube thingy that comes with it.

Then, the seals would be able to withstand the 400 degree oven?

the chance of getting them out without bending them or tearing is about nil, it looks like.
Anybody ever succeeed doing this before?
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  #9  
Old April 17th 2008, 20:45
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wrenchnride247 wrenchnride247 is offline
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Quote:
Originally Posted by gonebuggy View Post
What makes the Brembos more costly to coat? Surface area? or does the paint know the difference in their pedigree? lol

Alex
...Well, the ATE kits cost about $15 US per piston (one in each caliper)

Brembo's have FOUR pistons per caliper, and the kit is $45 US for EACH piston... you do the math. (I had to do all four corners on mine $45 X 16 = ) small price for your safety.
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans

1962 SC 1776cc SP 944NA brakes, 993 wheels

VKG
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  #10  
Old April 17th 2008, 21:09
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wrenchnride247 wrenchnride247 is offline
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Quote:
Originally Posted by Clatter View Post
I'm trying to get around the $800 penalty for replacing the seals.

The pistons were pretty 'extended' due to the car they came off of had worn pads.

Then, they were very carefully scraped clean using dentist tools, scotch-brite, and brake cleaner.

Next comes the paint remover, then seperate the halves and finish the cleaning.

Thinking that i could push the pistons back in, and mask w/duct tape for blasting.
(All of the fitting holes would be plugged).
Flush out all of the old fluid from the cylinders using the brake-clean and the long tube thingy that comes with it.

Then, the seals would be able to withstand the 400 degree oven?

the chance of getting them out without bending them or tearing is about nil, it looks like.
Anybody ever succeeed doing this before?
From the sound of it...your outer seals would most likely tear trying to save them for reuse. Do you have the style with the dust boot attatched to the piston, or the ones with a "scraper type" seal? When I first ordered my kit's they sent the wrong style (scraper style).

The inner seals would not like brake cleaner. In my kit instructions it states use only brake fluid or brake assy lube in the kit on the seals. The baking process would likely dry the inner seals out making them harder. It's a unhealthy risk IMO.

Sounds like your cleaning on the outside is good. The caliper paint kits work fairly good depending on the prep work...the cleaner the better.

If you try and split the caliper halves you will encounter some M5 (IIRC) button head screws holding the brake pad plates at each end inside were the pistons are. These are VERY hard to remove. Also, the four main allen bolts holding the outers together are VERY hard to remove.
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1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans

1962 SC 1776cc SP 944NA brakes, 993 wheels

VKG
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