1980-81 GL1100 front brake-caliper question.

[Greb]

Hello everyone. I just joined the forum officially, but I've been reading here for a couple of years sine I bought my 80-81-err 83, Frankenstein bike.

Long story short: I have a 1983 registered GL1100, but as far as I can tell most of (probably all) its parts are consistent with the 1980-81 models, also the 1-piston front brake calipers. This isn't uncommon for 70s and 80s bikes here in Norway as sometimes bikes would be overwintring at dealers for a year or two if they weren't able to sell them.

Anywho, on to my frustrating issue. My front left brake-caliper. It's almost impossible to bleed, and I have found out why: The threads on the bleed-screw (not the screw itself I've changed that, but the caliper) are so worn that air will leak back in through them. Therefore I ask thee, any suggestions?

My thoughts:

- I've though about finding new original calipers: Impossible and probably too expensive.
- I haven't been able to find reproduction ones so far.
- I've tried finding out if I can use calipers from the other years (the two-piston kind) by changing brackets perhaps, anyone know if this is possible?
- Does any of you fantastic people here know of any OEM calipers that I could change to instead.
- Or, does anyone know of any reliable used-parts vendors on ebay or the like that would be able to ship me used ones that I can rebuild over here in Norway?

My primary concern is getting a reliable solution that works and that can get me riding my baby safely for even more years to come.

I welcome any answer and discussion from all of you,
cheers!

- Greb

[DaveO430]

Yes you can use 2 piston calipers with the correct brackets. If the bleed screw will tighten so it won't leak unbolt the caliper and turn it so the hose connection is at the highest point and loosen the banjo bolt to bleed the air out.

[Greb]

In that case, great! Then my options for finding replacements are a bit better.
Interesting work-around, I'm trying to imagine how this would work when bleeding through the banjo bolt. Are there any guides on this that you or anyone else know of?
I'm wondering how much you're supposed to loosen the banjo bolt and if you shold retighten it between each pump on the master cylinder, as you would bleeding normally?

Thanks for your hjelp so far DaveO430!

[DaveO430]

The purpose of bleeding is to get the air out, the air is lighter than fluid so it is at the highest point in the cylinder, normally the bleeder screw is at the highest point but if you can't use it get the banjo bolt to the highest point. Take the caliper completely off the bracket,wedge something between the pads and hold as high as the hose will allow. Just loosen it slightly, enough to let the trapped air escape and yes, close it between pumps.

[Greb]

Makes perfect sense of course, thanks again. I'll try this method and see if it'll help.

Do you, or anyone here, know of any new aftermarket solutions that will work if I want to change brackets and calipers completely?

[DenverWinger]

Another way would be with the caliper off, work the brake to push out the piston to the point it would be at if the pads were worn out, then with the banjo bolt at the highest point use a "C" clamp and push the piston back into the caliper. Same as if you were replacing pads. The air and excess brake fluid will return to the reservoir.

[RBGERSON]

Lots of those calibers available here..check eBay,etc. for under $20 I know shipping maybe steep to the EU..but usually can be sent as a gift so no taxes added..I may have one if you're interested I can look through my parts stashes

[jeffcosmo]

Heli-coil the bleed screw. Simple and cheap.

[Greb]

And the work-arounds and solutions keep rolling in, thanks everyone!
I especially like your work-around DenverWinger, simple but elegant. I might try that one first, and revert to DaveO's solution if that doesn't work for me.

Sure RB, if you've got a spare left-side caliper in good order that you would be willing to part with I'm definetly interested. I've seen several calipers on ebay and the like and some do mention in their description that the bleeder-threads are stripped, which makes me slightly worried that this might be the case with a lot of used calipers for sale on-line.
I have a fantastic vendor and mechanic here in Norway that specializes in old (meaning he only does '89 and earlier) japanese bikes, and he hasn't gotten a hold of any one-piston calipers as of yet. I will however ask him if he might have the two-piston variety along with the brackets if they might be used.

jeffcosmo, have you tried doing this yourself? I guess it should work if I can drill open the hole precisely and squarely for the helicoil or timesert to fit.

Again, thanks a lot guys. I feel I have an arsenal of possible solutions and contingencies to try out now. Awesome!