Front Brake Help Needed

[Joeacme]

I have A 1982 Gl1100 that has the left front brake caliper locking up. I rebuilt it , replaced it , replaced the hose leading to it , bled it , and cursed at it. Both calipers are fed off the front master cylinder. There are no kinks in any lines. The right caliper works perfectly so I don't think it's the master cylinder.I've tried everything short of the master cylinder and spent a lot of money with no results. If anyone has seen this before or has a solution , I would appreciate a reply. IT'S TIME TO RIDE. Thanks

[Dougal]

Sounds like crud behind the caliper seals. Remove the caliper pistons and seals, make sure the groves the seals sit in are clean and free from corrosion, fit new seals, clean the pistons with something like WD40 (the idea is not to add t o any wear to the pistons) and reinstall them. Refit the caliper and bleed the system.
When replacing the pistns they should go into the caliper with thumb pressure only. If they dont then there is prob still some crud behind teh seals.
If the pistons are realbad carefully use a fine metal polish and remove any bad rust spots with a sharpscraper,being careful not to damage teh piston working surface.
When installing the seals and pistons it is important to keep everthing clean and lubed up with brake fluid.

Keith

[Bandanna]

WELCOME JOEACME TO NGW............

FEEL DOUGAL MAY HAVE YOUR ANSWER MY FRIEND.......

I ALSO HAD THIS PROBLEM,AND WAS SOLVED PRETTY MUCH THE SAME.........

HOPE DOUGALS ANSWER HELPS YOU............

ENJOY YOUR STAY WITH US...............

[Joeacme]

I took the caliper off and took it apart . Your right , there was crud behind the seals. I cleaned everything , lubed it with brake fluid and put it back together. The pistons pushed in with finger pressure. After I mounted it I still had the same problem. A teacher at the local tech school recommended pushing the pistons on the right caliper in , holding them in, and bleeding the left caliper. He seems to think air trapped in the right caliper might be preventing the left caliper from retracting . I'm going to try that next.

[Chewbacca]

Sounds logical to me. As long as they slid in with thumb pressure, you should be having no problems at all. I'm impressed you got your piston out though, I had a hell of a time getting mine out. I had to grab them with vice grips and wrench on them for about a half hour a piston . Needless to say, now I need new pistons, . Good luck friend!!!

[Zryder]

What I did was before I did anything was got the calipers off , then tweeked the brakes using the preasure to extend and release the pistons . And if one side extend out before the other , I just put something into tjhat side when the piston there is almost fully extended till the other pstion is there . A idea after the fact eh LOL .


Zryder crosso

[Chewbacca]

LOL, I wish I could have done it that way. I mean, it was my fault. I decided to strip the bike and had taken the lines off and everything before I decided to powdercoat the callipers with the frame. So I tried to blow them out with compressed air at work. I put a shim in front so that neither piston could come out quite all the way, then I connected 750 psi to the banjo connection. Those pistons didn't even budge. Once I got the pistons out, I discovered that the thinner seal (dust seal) was rotted and actually pinching between the calliper cylinder and the piston (not where the groove is but actually squishing out the top). One hell of a seal if you ask me

[Zryder]

My hat is off to you for you doing the work . Thats what I've allways done . If I got stuck I'd look at great places like this site .


( Z ) crosso

[Bandanna]

SPOT ON JOE..............

LET US KNOW HOW IT GOES MY FRIEND.............

CHEWBACCA,I HAVE ALSO DONE AS YOU HAVE IN THE PAST BUT LEARN BY THE EXPENSIVE MISTAKES............

SAFE RIDING............ LADIES AND GENTS.............

[Joeacme]

After reading some of your horror stories , I guess I had it pretty good. I rebuilt all the calipers on this bike and all popped out with about 90 psi of air. I didn't get a chance to work on the bike today(my loss). But , tommorrow after work might be a good time. Your input was very helpful.I'll let you know how it turns out.

[Frenchy]

Joeacme,
Have you got your brakes working properly yet

[Joeacme]

I haven't had he chance yet. I hurt my back at work . I'm just getting better now, so maybe in the next few days. This is very depressing . I want to ride!

[Frenchy]

If it's not working properly when you get it all back together, you might want to look at the distribution block, & the lower brake line to the problem caliper. The same nasty gunk you found in the caliper could be plugging one or both. If the line or block is patially plugged, it will allow the brakes to be applied because of the force of the master cylinder, but not allow the pressure to equilize.

Just a thought

[Joeacme]

Sorry it took so long, but here's the latest. Tried to compress the right caliper while still attached to the lines. Would not compress , even bent my c-clamp. The lines stayed soft and pliable . The mater cylinder lever got hard as a rock. No fluid would return to the reservoir. I'm guessing that the master cylinder will push out but not allow any return. My guess is the cups inside the master cylinder got hard from siting all those years and will not allow return flow. Any thoughts on the matter? I've heard rebuilding these is not as easy as it sounds. I may find a used one on ebay cheap, but I might have the same situation.

[WINGMAN]

I have an idea. I had a similar problem with the clutch on my GL1200. I'm guessing that the the clutch master cylinder operates pretty much the same way as the brake master cyclinder. If this is the case, then this might work. When I purchased my GL the guy that sold the bike to me tried to rip me off. Said there was nothing wrong with the bike. On the way home, the clutch started slipping. I barely made it home. I was really pissed when I found a receipt under the trunk mat. The dude had taken the bike in for a clutch overhaul just 3 days before he sold the bike to me. He paid $150.00 bucks to have the system cleaned and bled to no avail, so he probably thought the clutch was messed up. I immediately went through the same routine of flushing the system, again, with no results. A guy at a Honda dealership told me to check the "bleed back valve". It's a tiny little hole at the bottom of the master cylinder that you can see after draining it and removing a small oval metal thingy called a "protector". The guy told me to take a tiny pin drill and ream it clean. IT WORKED! That jackass probably still thinks he ripped me. His BIG loss! Anyway, if the brake master cylinder has one of these tiny valves, do the same thing, maybe that will solve your problem. Sorry for the long one, I just had to gloat since I never got the chance