Problems replacing front brake pads-'77 GL1000

[ccmonson]

I'm pretty new to fixing up old bikes, and any help would really be appreciated. I've got a '77 GL1000, and I'm trying to replace the front brake pads. Unfortunately, I couldn't find an article on here (or anywhere) about GL1000 brake pads and am kind of winging it based on articles about other models. I have the caliper off the bike and the bleed screw opened. I've taken out the old brake pads. I'm trying to push the piston back, but I can't get it to move more than about a millimeter for anything. Any thoughts? Any info or redirection to another post on the matter would be really great. Thanks, guys.

[offcenter]

Put one of the old brake pads in the caliper and use it as a flat surface
against the piston. Now take a large "C" clamp and put it around the
caliper and brake pad, using the old brake pad to push the piston
back into the cylinder by tightening the "C" clamp.

[portugeezer]

I have very large channel locks that I use for this. The C clamp way is common. If it won't move it might be frozen.

[offcenter]

Good Idea! I never thought of that. I've been using the C clamp on all my
disk brake vehicles for years.

[Fred Camper]

Geezer, I have one of those "mother" of all channel locks and never tried that either. Quicker than a c-clamp if the piston is of normal friction. Appreciate the post.

[spookytooth]

Wrap the business end off your channel locks with a bit of duct tape to prevent the teeth from marring your calipers!

[Fred Camper]

My son just tried this channel lock method on his mom's Chevy truck during pad replacement. It sure works easier than using a c-clamp. Both ways work, just use what you have. Electrical tape is a good idea for the paint protection.

[jerry8671]

It could also be a collapsed brake hose. May not see it on the outside of the hose but internally it may be restricting the fluid to flow back like a check valve

[wjnfirearms]

All of the above.

With the bleeders cracked, the pistons should retract. Me thinks you're looking at a caliper rebuild.

Make sure to also thoroughly flush out the master cylinder after you repair the primary problem. I had an issue with my '77 where the front brakes wouldn't retract fully unless I cracked the bleeders. The return hole in the bottom of the master cylinder can and will get clogged with sediment and won't allow the brake to let go. Wiping out the cylinder reservoir and a couple long flushes corrected my issue.