I tried changing the front brakes on my brother's 84 GSL.
I opended the caliper as much as I could with a c-clamp but I could not get the pads far enough for it to fit back over the disk. Do you need to take the caliper apart to get it over the disk and then put it together again on the disk or is there some other trick?

 

It will push in all the way which should be plenty of clearance. Sometimes you have to go slowly to let the pressure subside. Are you putting an even force on the caliper with the c-clamp? If not try using a bridge across the open end such as the old brake pad. How far is the caliper pushing in? Or how much is left sticking out?

 

If all else fails open the lid on the reservoir. Be careful it isn't going to splash on anything and no dirt is getting in there

 

if the pistons are very difficult to push in, when you put it back together, you may find that the calipers are shot and they will drag a ton!!! you can rebulid you calipers cheap. the "bridge" thing works as cosmicbang was saying. i always always, use a the old brake pad.

 

I'll be replacing mine next summer so I've looked it up in the manual and it says to open the bleeder valve at the calliper.

Noone ever seems to mention this method though.

 

Manual? we don't need no stinkin'...lol. Actually just I never had to open it and wanted to avoid getting air in there unnecessarily.

 

Now is the caliper going to be so far back that it will be flush with the opening? Because right now there is about a quarter of an inch out.