Hi there mate,
When i converted my escort cabbie to rear discs the hand break used to stick on. this is due to the mk5 hand brake cable.
The horse shoe shaped piece of metal under the car on the mk5 cable is bigger than the one on the mk4 and there for wedges its self in the tunnel under the car and makes the hand brake stick on. so remember to use the horse shoe off the mk4 cable and u will be ok. Just thought this may be worth u knowing!