So I have several projects going on which means I try to group together similar jobs. Last week I rebuilt 2 sets of 34mm forks, installed brass bushings in two swing arms and changed steering head bearings in three bikes to tapered. I have a pair of two piston front calipers to rebuild and read up on the techniques before I started.
Mounted a master cylinder near on my work bench and started to free up the caliper pistons. One came out easy, I then butterflyed that caliper and was able to get the other out. By then, my finger tips were all wrinkled from the brake fluid. (Gloves had come off about ten minutes in). The two remaining halves spent overnight in vinegar.
Next I took them out and hit them again with penetrating fluid and tried again with the master cylinder to get the pistons out, nothing. Then tried air pressure, no go. Another overnight in Evaporust. Brake fluid under pressure finally spat the second last one across the bench.
I went to Canadian Tire and got an 8 mm grease zerk that fit into the bleeder hole, blocked off the other hole with a cardboard gasket and a piece of metal bolted over it and started pumping grease. About 15 pumps and the piston is almost out, one last little squeeze and the piston is finally free! There was about a tablespoon of grease that finger-wiped out from the caliper and went right back into the cartridge. I had been worried about grease all over the place, but didn't happen.
So, the take away on this tale to you members just starting, read the tech section and try it! Don't be a sceptic like I was. The regular contributors here have done it before so follow their lead.
And those of you with post counts way up there, thank you for your input, guidance and often, patience. Even the most callow questioner may turn into a valued contributor.
Mounted a master cylinder near on my work bench and started to free up the caliper pistons. One came out easy, I then butterflyed that caliper and was able to get the other out. By then, my finger tips were all wrinkled from the brake fluid. (Gloves had come off about ten minutes in). The two remaining halves spent overnight in vinegar.
Next I took them out and hit them again with penetrating fluid and tried again with the master cylinder to get the pistons out, nothing. Then tried air pressure, no go. Another overnight in Evaporust. Brake fluid under pressure finally spat the second last one across the bench.
I went to Canadian Tire and got an 8 mm grease zerk that fit into the bleeder hole, blocked off the other hole with a cardboard gasket and a piece of metal bolted over it and started pumping grease. About 15 pumps and the piston is almost out, one last little squeeze and the piston is finally free! There was about a tablespoon of grease that finger-wiped out from the caliper and went right back into the cartridge. I had been worried about grease all over the place, but didn't happen.
So, the take away on this tale to you members just starting, read the tech section and try it! Don't be a sceptic like I was. The regular contributors here have done it before so follow their lead.
And those of you with post counts way up there, thank you for your input, guidance and often, patience. Even the most callow questioner may turn into a valued contributor.