Quote Originally Posted by HK1837 View Post
You have to find HZ or WB rear calipers or rebuild yours. Early UC and A9X are the same basic thing too. These have an inbuilt handbrake mech that normal calipers won't. XB-XE? had a very similar caliper and you might find some bits to rebuild yours on one of these. In all honesty the simplest way to fix it is to remove the disc brakes and replace the axles with drum brake axles and rear backing plates/drums.
HZ rear calipers are different to WB, but the same as A9X, & the UC is very similar to HZ also, but made for a narrower disc rotor. The WB are different in the plumbing connection.

I would just get them overhauled. Where are you located ?

Dr Terry