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Pitted caliper piston- can i use it?



I am rebuilding my front calipers and ran across this pitting on one of the pistons. Will I have a problem using this?

Thanks!

Old 03-30-2012, 08:33 AM
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I would get a new one. The pitting can make it leak and/or damage the seal.

Kay
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Old 03-30-2012, 08:35 AM
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That is beyond pitting ... much safer to get a new one !

Cheers !
Phil
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Old 03-30-2012, 08:41 AM
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I agree that the best answer is to get a new one.

This corroded area was probably outside of the inner seal (the square-cut O-ring) in the caliper cylinder, and was therefore exposed to the elements, probably due to a failed dust boot. While it's possible that you could polish this area down, unless you could get it perfectly smooth without altering the dimensions of the piston, it may damage that O-ring, or allow fluid to leak if depressed all the way into the cylinder, such as when new pads are being inserted.

There's no real up-side to re-using this, and you might think about replacing the whole caliper.
Old 03-30-2012, 09:05 AM
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the only pistons I've seen available are for earlier years? I have a '79. recommendations on where I can find some?
Old 03-30-2012, 11:00 AM
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They are available from Eric Shea (pmbperformance.com)
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Old 03-30-2012, 11:46 AM
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Quote:
Originally Posted by fitchn View Post
They are available from Eric Shea (pmbperformance.com)
+1 Eric does AMAZING WORK on brakes.

Also... when it comes to brakes, no matter what I will not skimp. When in question about the very thing that keeps your life safe every time you press that pedal, it's best to make sure it's rebuilt properly or new.
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Old 03-30-2012, 12:08 PM
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Thanks for all the advise everyone. Those were my thoughts but just wanted to make sure before I shelled out another $70+ per caliper for new pistons. I will probably eventually upgrade to big brakes and didn't want to spend unnecessary money getting these up to par for the time being.
Old 03-30-2012, 01:38 PM
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Pitted caliper piston- can i use it?

yes, just use thinner pads
Old 03-30-2012, 04:36 PM
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That is not pitted... it is dead.
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Old 03-31-2012, 06:57 AM
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I would measure how deep the seal is in the bore and see if that area will touch the seal. If not then it would be ok to use (especially for a short time).

-Andy
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Old 03-31-2012, 09:27 AM
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Ask yourself this question....when driving down the road...and a big truck carrying gasoline pulls out in front of you and you have to make an emergency stop....will you make it with that piston?
Or...for the sake of a few dollars...?
Bob
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Old 03-31-2012, 10:30 AM
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Everyone makes very valid points. Thanks guys. With that being said.. new pistons it is! That is as long as my inspection of the calipers don't show any pitting as well..
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Old 03-31-2012, 10:39 AM
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Quote:
Originally Posted by Eagledriver View Post
I would measure how deep the seal is in the bore and see if that area will touch the seal. If not then it would be ok to use (especially for a short time).

-Andy
My thoughts exactly...I doubt the pitted area is anywhere near the business portion of the piston. What would affect this is the brake pad thickness. The further the pad wears, the more the piston extends out from the seal.
However, if it were mine, i'd replace it
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Old 03-31-2012, 12:06 PM
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If the seal isn't touching it, which I doubt, it's just as good as a new.
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Old 03-31-2012, 01:47 PM
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OUT, it goes. Sooner, the better.

Best!

Doyle
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Old 04-01-2012, 05:02 AM
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Using that is a good way to meet your local ambulance crew.

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1968 911S "Leona"

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Old 04-01-2012, 06:08 AM
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