LR rotor is scraping on rotation ('94 855T)

[BlackBart]

Oh, here's an $80 no-brand reman at ipd...
Photo shows an Ate part.
https://www.ipdusa.com/products/7312/11 ... gLRjfD_BwE

[JimBee]

I bought a couple of 850 rear caliper rebuild kits for ~ $11.00 each. If you're going to order a reman, you could check with Rock Auto, e.g, the following:
https://www.rockauto.com/en/catalog/vol ... liper,1704

What I might do. If I had a little extra time, (wearing protective lenses, of course, when anything in that system is pressurized) I'd pull the pad from that side, maybe slip a thin piece of wood in that space to protect the rotor then put some significant pressure on the brake pedal to see if the stuck piston will pop out. It might just be somehow frozen to the rubber seal. If the piston isn't pitted, I'd try to clean up the seal groove and replace the seal, lube it up good with the right stuff made for caliper reassembly and try to reuse it. If it works, you've got an extra one for inventory or return it.

Hint from a local rebuilder: Even if a piston looks shiny, there will be some film on it. Soak it overnight in 90% denatured alcohol before reinstalling.

[abscate]

Oh, here's an $80 no-brand reman at ipd...
Photo shows an Ate part.
https://www.ipdusa.com/products/7312/11 ... gLRjfD_BwE

Text on rebuilt calipers

Rebuilt units are completely dis-assembled, cleaned, examined and tested for their failure points before re-assembly with new parts and sold as "Rebuilt".

The theory that "rebuilt parts" are just going to fail, is false. When a product is rebuilt it is torn apart and examined for their failure points, cleaned, and often rebuilt with new and improved parts to ensure that the next phase of that parts life is a more successful one.

Rebuilt products will help you save time and often money when it comes to finding these usually rare or out of production parts.

We strongly believe in the rebuilt process and product result. We feel confident in selling these products for you and your Volvo!

In my experience, the rebuilders use pot metal for the pistons and sliders. Unless they identify the rebuilder and attest to the use of good parts, I would assume a short lifetime on these. The pot metal piston on my rear V70 caliper froze solid before the brake fluid charge interval of 24 months occurred!

[BlackBart]

I believe that's the very text I read on Nugeon calipers. They were US-built until economics caused them to move to Mexico. Their video of their process seems sound. (in 2013)



I note he says 50% of pistons don't pass - so, as you said, which ones go back in?

[BlackBart]

If you're going to order a reman, you could check with Rock Auto, e.g, the following:.....

I saw that Nugeon price of $74 and thought, ok, can't beat the $68 at Pelican.....but that's the total price with core included. Yow. It's only $40. I haven't bought anything from Rock Auto in 10 years, hmm.

[abscate]

If you are running the car for more than a year, go Volvo or at least FCP

The last screaming smoking stop on I90 inBoston , courtesy of a guy with no brake lights, convinced me to stay new OEM on Brake parts

[JimBee]

Aside from piston quality, I think the most vulnerable part to fail on an oem rear caliper is the seal groove. If the dust boot fails, even leaks a tiny bit, moisture can get in there and cause some rust to build. The bore isn't that critical; the seal takes care of holding in the fluid around the piston. But dust boot leakage of ambient moisture seeping around the groove side of the seal can cause a leak there. Before I would turn in an ATE I definitely would pull the piston(s) to see if they're reusable. The Centric kits come with the two o-rings that go between the two halves.

If you rebuild one, you can use a Dremel or similar tool with a brass wire wheel to clean out the groove, then flush it with some brake cleaner.

[abscate]

Do you guys rebuild these and hone the caliper cylinder? I’ve done that years ago with wheel cylinders but’s never had luck with disc calipers. You definitely need new Orings if you break thecaliper open.