Howto: Fit S60R rear calipers to an 850

[dooby]

Hi guys,

way back when I bought the brackets to put the Porsche 993TT calipers on the front of my 850, I also asked CJ to send out the rear brackets for fitting S60R rear calipers.

Many thanks to Tony who helped me eventually source a set of these elusive rear calipers.

Thanks also to Blackbeast, who (since he would have nagged me about them again this year at MRG) made me realise I should sort them out now the weather's nicer :-)

Today, I fitted them.

With the rear wheel and disc off, I unclipped the handbrake shoes bottom spring. I found shrew-nosed pliers worked well for this, grabbing the inside of the spring and pulling the hook back and out.



The shoes came out of their clips and away with the smaller top spring (on ground) leaving the adjuster screw resting on the ABS sensor.



I decided I wanted to remove the backing plate from one side to cut it right for the larger caliper. Here I've removed the 4 bolts holding the backing plate then realised rear hub will have to come off also, so I removed the hub cap.



I undid the M22 nut:



And removed the hub and bearing from the stub axle, followed by the backing plate.









Now the backing plate was removed, I could temporarily re-fit the hub and bearing assembly to test-fit the disc and caliper on its bracket.



The bolts for the S60R rear calipers and the 850 rear calipers seem to be the same (except one's black, one's silver). I found problems using those bolts with the caliper bracket. It's slightly more narrow than the 850 rear caliper bolt-through points, so since the bolt isn't threaded all the way along its length I was trying to tighten into a non-threaded section of the bolt when fully tightening.

I tried using a washer, but settled on a slightly shorter bolt with thread all the way along, from a local ironmonger.



Next, time to get the Dremel and mark out a 1st cut.





After a few more cuts, this was achieved:



Here's what it looks like off the car if anyone wants to try using this as a template.



On the offside, I did this in mirror-image without removing the plate from the car.



Pop the handbrake shoe assembly back on...



And a shiny new disc.



Now, I'd moved the brake pipe over onto the S60R caliper and was trying to gently bend it enough to allow the caliper to go over the disc and onto the mount points.

This was made trickier by me leaving the pads in place, so on the nearside I removed them and there was more clearance to get the caliper over the disc, without as much strain on the brake pipe.



Quick test with a wheel to check they clear the 17" Pegasus - I assume so, as they were a no-cost option on the S60R AWD I believe.



Plenty of spoke clearance even without a 3mm spacer for the rear. I'll still keep the spacer, but nice to know...



A shot of the piece of metal I removed from the offside backing plate, whilst it was on the car. Ignore the extra silver line I etched in it, I had forgotten I needed to take away material from further up.



Nearside gets its handbrake shoe clips back.



And is reassembled ready for swapping the brake pipe over.



Brake pipe swapped.



Gentle radius curve to avoid kinking the pipe. It's not as close to the suspension spring as this photo makes it look, plus I think I gave it another tweak after the photo.



It can be confusing working out how the caliper bracket is oriented - here's a shot showing the nearside, along with my new shorter mounting bolts.



Nearside all done, ready for bleeding.



Bleeding and handbrake adjustment done. It's harder to adjust the handbrake through the wheelnut holes, but it can be done.

All on the ground, ready for a test.

Did I say the weather was getting nicer? Must have been mistaken...



If you don't want to spend an additional 20 minutes clearing up copper slip from all over your boot, I recommend you empty the boot of your tools before you go off driving in a style appropriate for bedding in brakes...

Cheers, Pete