Is rebuilt caliper piston pitting industry standard ?

johnnyfd · Post by **johnnyfd** » 10 Jul 2015, 21:23

When I went to replace my front pads and rotors on my 96 850 I found the drivers side caliper piston dust boot had popped out of place on about a third of it. I could see that the exposed piston had some rust on it and I could not get the boot to push back down into the bore so that it was in place again. I assume this condition would require a complete rebuild of the caliper so I went to autozone and picked up a rebuilt one. I am open to comments and suggestions about this condition but my main question is whether or not it's people's experience when buying rebuilt calipers that the portion of the piston which can be seen has pitting on it.? The rebuilt I bought has pitting on the visible part of the piston and I'm concerned that there is pitting on the other parts of the piston where it might have more of a negative effect but I don't want to go all over the place looking for a better rebuild if this is the way they normally look when people buy rebuilt? Do you guys think the hidden part of the piston is pitted and if it is will this cause problems with the piston in the near future ?

skloon · Post by **skloon** » 10 Jul 2015, 21:48

If the boot came off I assume moisture got in and started corroding the piston- I have had cars fail inspection because of this and some pass I think it depends on the environment. Some calipers now Cardone for example seem to paint or clear coat the piston so it doesn't corrode even with the boot off- but the coating peels so I don't think you are any better off

johnnyfd · Post by **johnnyfd** » 10 Jul 2015, 22:09

Have you seen pitting on the visible portion of the piston with some rebuilt calipers and what's your experience with these calipers longevity?

Post by **kahl** » 10 Jul 2015, 23:01

The quality control on some of these calipers is very poor. Two years ago I got a set for the Passat from Autozone and found that the bleed screw threads on both were buggered up. The next set I got had the same issue. Changed stores to a NAPA rebuilt set with no issues.
If you are unsure about a brake part I would return and exchange until you are satisfied with a quality replacement.

Post by **jreed** » 11 Jul 2015, 05:11

I bought a set of remanufactured front calipers for a '97 855 GLT from Advance Auto last October for about $40 each during one of their frequent 20% off sales. The calipers included the brackets. They looked good overall, fit perfectly and I was pleased with them -- would do it this way again... your mileage may vary.

http://shop.advanceautoparts.com/p/wear ... fragment-1

Post by **cn90** » 11 Jul 2015, 09:36

Been there done that:

Hydraulic Rebuild:
https://www.matthewsvolvosite.com/forums ... =1&t=37721

Make sure you read the thread from 03 Nov 2013, where I posted seized caliper piston.

The rebuilt caliper is hit-and-miss:
- Sometimes they repolish the pitted piston (= dangerous practice).
- Sometimes they used a new piston.

Your best bet is to go to junk yard and get a Volvo OEM caliper with good boot, then bring it home and extract the piston and transplant it over. Use only FTE seal kit.