[urq] Rear Calipers

[Steve Eiche]

Jack,
The rear calipers are pretty easy to take apart.  Certainly not as simple as the fronts, but not a big deal.  All you really need in terms of "special tools" is the piston turning tool, and a long nosed circlip pliers.  I just took a set apart in under 15 minutes.  I have never used one of the tools that turns and presses in the same time and haven't had a problem winding them in or out.  Once you unscrew the piston from the bore, the rest of the disassembly it is pretty self explanatory.  Just be careful removing the circlip holding in the parking brake mechanism.  There is a spring that will throw the guts right at your forehead once the circlip is released.  BTDT.  As for reassembly, getting that spring and circlip in again is a bit of a trick.  I used an arbor press (a vise or drill press would probably work as well) and a socket to hold the assembly while I got the circlip back in.

As for rebuild parts, you will want the seal kit, which is available at the dealer, and then the shaft seal for the parking brake mechanism and one O ring that goes on the adjuster.  Sorry, I don't have the specs for those at the moment.  There is nothing really special about those parts, but you can't get them at the dealer.  Any good seal supply shop should be able to match them up for you.  You will also need the special assembly lube for the internal parts.  It looks like a thick grease, but is compatible with brake fluid and high pressure.  I THINK Permatex 24110 is the right stuff, but I haven't been able to verify that yet.

It is probably cheaper/easier just to get a rebuilt set of calipers.  Last I looked they weren't too expensive.  I just wanted get get mine put together as I wanted them.  So, now I will have one set of red powdercoated calipers, and one set of OE looking cad plated calipers.  I did start with calipers from rust free CO cars, so they were in good shape to start with.  YMMV.

Steve

Jack wrote:

I'm in the position of placing the Ur S4/6 rear calipers/rotors as an
upgrade to my 83 UrQ. I?ve read with interest the rebuild notes published on
one of the lists for rear calipers, although I can't remember exactly where
it is right now. At what point should I consider the calipers written off,
as unserviceable and buy something new or already rebuilt? Which was the
recommendation of a shop I took them too to have them wound back?which they
wouldn't do not that I fault them for not doing it!

I don't have any of the tools to properly do the caliper rebuild, but am not
opposed to getting them, a guy can always have more tools..; ^) 

But, I've tried to wind back the calipers with a wind back tool and it bent
the metal rod that's supposed to twist the piston as it is compressed and
wound back into the caliper body. So I must be doing something wrong? I've
got like 4 of the rear calipers as parts to mess around with and they all
seem to have the same problem, so it's got to be me!