rear calipers

[90LSC]

I am planning to put fresh brakes on my 90 MkVII in 2-3 weeks. I was looking in my Chiltons manual and it looks like the rear calipers on the 89-90s were designed by an idiot. The rear calipers on the 91-92s appears to be more mechanic friendly. So.....here is the question for anybody who knows----can I put 91-92 rear calipers on my 90? I think I can but I want experienced MkVIIites to confirm or deny. All info/advice is ALWAYS gladly accepted. Later

[Lscman]

Yes, the rear brake calipers were designed by idiots at Kelsey Hayes. The idiocy is limited to the emergency brake actuator assy. No, later style calipers for 10.5" rotors will not fit your 11.35" brake setup. If the emergency brakes work and do not need rebuilt, the issue is irrelevant. The caliper piston bores can rust and make the piston difficult to rotate back into it's bore. In those cases, replacement is necessary. On a positive note, the complex rear calipers can be purchased (as remanufactured) for $50 through most auto parts chain stores with your cores. I would not try to rebuild them, since the parts cost about the same. Original style directional rotors (right and left different)with their thin, composite hats cost about $100 each. Cheapo cast non-directional rotors are available for about $50. I use Wagner lifetime MX204 semi-metallic pads for optimum life and performance.

[90LSC]

Thanks for the reply. I've been doing some part numbers comparing and realized I may not be able to swap some parts. Didn't know that my rear brakes were a little bigger than the later MkVIIs and I'll take that as a plus.

What made me look into this is the fact that the 91-92 calipers are the "drop new pads in and bolt it back together" type while the 89-90 calipers are the "Damn I hope I get these micromanagement adjustments right" type. I personally prefer to keep things as simple as possible.

LSCman, what is your opinion (or do you know from experience) on my chances of swaping the 91-92 rear calipers AND rotors as a unit onto my 90 rear end??

[This message has been edited by 90LSC (edited February 12, 2001).]

[Lscman]

It should be a bolt-on swap, if you get ALL the bracketry and the rubber hoses. However, it takes about 15 minutes to rotate the pistons in 1/4 revolution increments until the caliper barely slips over the pads & rotor. Since the pads last 2 full years in full race track duty, I hardly feel the extra 30 minutes for a brake job every 2 years is a big deal. Once you get the caliper on fairly snugly, you simply ratchet the parking brake lever between full on and full off with a pair of pliers until all slack is removed & resistance is felt. Installers who arbitrarily skip the piston rotation "rough adjustment" setting & leave 1/8" or more play are the ones who have problems with the oddball parking brake. If your caliper is not rusted or gummed up, you should be able to rotate the piston with a set of decent pointed-nose pliers. If the brake adjustment is done properly, the parking brake will operate properly for the life of the pads.

[90LSC]

Again, thanks for the info. You are right, brake jobs are so far apart that the extra steps really aren't a big deal.
Now if I could just find a company that made slotted front and rear rotors for our MkVIIs........

[Lscman]

You will not find slotted, grooved or dimpled stock-sized rotors on any serious Road Racing ponycars or other vehicles with marginally-sized brakes. Such modifications reduce brake life, since they promote heat/stress cracks. They look good, but those mods are only practical on race rotor packages with lots of extra metal surface thickness and huge swept area.

[90LSC]

I'll file that info away for future use. Thanks for the input. Later