850 Rear Brake Repair - AGAIN - Tips

[scot850]

I will ask FCP if they will match on the Volvo parts. Prefer to buy from them as they give a lifetime warranty even if I fit them, Volvo only does that if they supply and fit them.

Thanks for the heads up!

Neil.

[PeteB]

Sure Scott, I used mostly FCP parts in our car and now we're thinking about keeping it a lot longer.

I added several new pictures to post #2.

[PeteB]

I found rear hoses on ebay made by FTE was this an OEM supplier?
I've seen the name and believe that they are good, can anyone confirm this?
"One of the leading OE suppliers" from here:
https://www.fte-automotive.com/

[mecheng]

I found rear hoses on ebay made by FTE was this an OEM supplier?
I've seen the name and believe that they are good, can anyone confirm this?
"One of the leading OE suppliers" from here:
https://www.fte-automotive.com/

My part guy had both ATE and FTE for the same price so I went with ATE which is the OEM supplier.

[PeteB]

Working on the rear brakes AGAIN!
I did the rear hoses shortly after the 2017 repair and now today the calipers look fine, not like
the insanely rusted ones from last time. So I believe that the drag theory was correct.
Pads are down to nothing and one piston is frozen again.
It seems that FCP no longer has Cardone rebuilds so I'll see if they will give me Centric
replacements to cover them.

[PeteB]

Managed to free the stuck piston and just did the pads for now. FCP says they will
give me a Centric as a replacement for the Cardone, I'll do it in the Spring.
Mileage is 139K + 63,462 = 202,462

Put ATE pads in the rear from FCP this time.

[FireFox31]

I've said this before, I'm fairly certain that the rate of a chemical reaction doubles for every 10 deg rise in temp, so hot dragging brakes rust a lot faster.

I want to thank you for this thread, especially the above quote. Your posts all those years ago helped give me the confidence to tackle my repeated rear brake caliper failures. Dealerships would simply swap on new pads and rotors only to be ruined by my rusty, frozen calipers they didn't want to bother with. Thanks to you, cn90's brake write up, and many others, I am working to maintain and preserve my calipers.

the [FCP] guy suggested that I just paint the new replacements before we put them on, claiming that they WOULD take them down the road as cores.

I asked them in mid 2021 and this is still true. I just bought four new Volvo calipers from them in order to be stripped and powder coated. FCP said they will still warranty them.

The weakness I'm seeing is the head of the caliper pistons. The exposed head gets rusty, that rust creeps down into the boot, spreads to the protected part of the piston, expanding the metal so it won't retract. For me, it's worse on the front than the rear. I've started a thread about painting my calipers for rust prevention. My next step is to apply Cerakote or another marine paint to the piston heads to prevent this rust. I've wasted thousands of dollars due to rusting calipers and will do what I must to stop it.

[PeteB]

Great to hear that this thread helped you that is why I created this thread.

[PeteB]

@FireFox31 I drove my son's car and head scraping sounds from the back SO looks like I'll be working on
them again. Have you found anything that works for the pistons? I did notice the rust on them in the past
and thought about at least putting some high temp grease on them as a protective layer BUT, I also concluded
that it should not go into the bore since it would probably drag due to being too thick. Caliper grease is the
obvious thing to use.
Have you found anything that works?

[abscate]

Pete, I’ve ordered and received rear piston seals and boots from Skandix courtesy of manov in France, who saves me $120 in shipping. Let me know if you are interested in rebuilding. Usual caveat about 850 to v70 rear brake compatibility applies.