Here,s how I freed mine , they were seized solid having been motionless in a damp garage since 1995
1 drill a 4mm hole through the aluminium body of the arm until you hit the steel pivot pin, do this approximately half way up the aluminum arm body as that is where the grease recess is situated on the pivot pin
2 soak overnight in a bowl of plus gas or similar penetrating oil
3 grip the single bolt end of the pivot in a vice, heat the bracket with 2 bolt holes and work it to and fro until it can be pulled off
4 heat the aluminium arm at the pivot end with a heat gun, get it really hot
5 tap the calliper end of the arm from side to side with a soft mallet, not too hard
6 apply penetrating oil and continue to tap the arm from side to side, if it doesn't move apply more heat and oil
7 once it starts to move grab the arm (whilst wearing welding gloves, its hot!) And work it to and fro
8 keep working it side to side and pull upwards at the same time, the arm will start to come off the pivot
9 once it is apart clean off the corrosion
10 drill out and tap the 4mm holes that you drilled and fit grease nipples
11 grease the pins and reassemble fitting new O rings at the top and bottom of the pivot pin.
