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Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Fri Jul 25, 2014 1:31 pm
by CYBORG
Most of the time anything you want to do, or is worth doing, is worth doing right. And is always more complicated then you first thought. But there's the fun of it action1 action1

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Fri Jul 25, 2014 2:43 pm
by Brant
Yes sir.

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Fri Jul 25, 2014 3:14 pm
by Brant
Think I am getting a little better picture now. 1980 1100 has a rear brake line with banjo fittings on both ends. Might be time to de-link the 83.

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Tue Jun 30, 2015 10:15 pm
by u093905
Great tip,just did it. Very straight forward. Thanks

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Wed Aug 12, 2015 12:09 pm
by adecood
I just saw this post on swapping out the rear master cylinder w/ one from a 1800. I too am trying to look at ways to improve the breaking performance on my 1200. And this sounds like another option. So one question I have is seeing that the 1800 has a larger piston which should translate into more force. Are there any modifications that need to be made to the caliper asm's. When you made the switch did you also rebuild the calipers w/new bushings. I am not a hydraulic eng so I am wondering can the rest of the system support the increased force from the new master cylinder? Seeing that this post started a while back I am wondering can someone post a follow-up on the real world effects of this rebuild. That would be nice to know seeing that the breaks are pretty important feature on the bike.

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Wed Aug 12, 2015 12:21 pm
by 82aspy
i haven't seen this done (or run across info) on stock 1200 linked brakes, or 1200 period, could be someone did tho,

i think the 1200 rear m/c uses a built in splitter (for one front & one rear caliper) so going 1800 rear m/c would prob work but only if intending to unlink the stock linked 1200 brake system/setup, which many do,

mounting would have to be sorted if doable, or how complicated it might be to go there, haven't seen info on that

turned out pretty easy for 1100 setups, however, the 83 1100 is linked but the rear m/c uses an external remote splitter,

pretty sure at least one 83 has gone with the 1800 m/c and don't recall mention of unlinking so could be for 83 only, easy to go eitherway

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sat Aug 15, 2015 5:40 am
by mhynze
What about a 76 GL 1000 ? Will this work on that? I'm in middle of a build

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sat Aug 15, 2015 5:50 am
by 82aspy
mhynze wrote:What about a 76 GL 1000 ? Will this work on that? I'm in middle of a build
might not be a big issue but, haven't seen info on that, or concerns finding good used, which was a big issue for the 1100 line

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sat Jun 04, 2016 10:23 pm
by steve.o
Anyone know how i can save this post as i just spent 2 hrs looking for it !
thanks steve.

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sat Jun 04, 2016 11:05 pm
by 82aspy
you can save it (the url) as a favorite/bookmark in your browser, or

you can save it in your profile on this site by selecting 'bookmark topic'

if you point on the wrench icon/button you will then see a 'topic tools' indication,
when you click on it, a drop down menu shows up,

the wrench icon/button is to the right of the 'post reply' button, which is on the left of each page at the bottom or underneath a post or thread

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sun Jun 05, 2016 5:21 am
by steve.o
Thanks! i just ordered one of ebay !
but after buying it, the add says for fuel injected model, will this still work on my gl1100 ? or are all master cylinder same ? thanks again,
:IDTS: :IDTS:

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Sun Jun 05, 2016 8:37 am
by Brant
Just to add to the pool of knowledge, I did this upgrade to my 83 and unlinked the brakes. Simple on the rear brake, removed the splitter and used a rear brake line from an 80-82 1100. The front brakes I used lines from a 80-82 and a splitter. I did replace the front master with MC for dual calipers. The lines could stand to be a bit longer and I plan to replace them as funds allow. Overall braking improved.

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Mon Jun 20, 2016 11:56 am
by Buli
Hello. Here has been a debat how bigger brake master cilinder piston increases brake power. IT DOES Not. When master cylinder diameter increases u need more pedal force to get same brake power. So when u swap 1800 master to 1000 u get less brake power. In this case u only hafty press little harder rear brake pedal. But it is good to know. Great post anyway

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Fri Aug 26, 2016 12:25 pm
by Easter
Sorry for the delay in answering some of the questions about this swap. I haven't kept up with the comments.

I have now been using this for three years and am completely satisfied that it is as good as stock. As someone said the used 1800 MC can be had for about the same price as a kit for the stock MC. I would imagine there are other MC out there that can be adapted in the same way.

Yes you do need to switch brake lines. I was switching to stainless anyway so I didn't give it much thought. :crosso

Re: Adapting Rear Master Cylinder from GL1800 to GL1100

Posted: Fri Oct 21, 2016 11:49 am
by dougeferguson
Just found out that my 83 GL1100 master cylinder needs replacing. How did you fix the problem with the hard line flare fitting on the old master cylinder verses the new banjo bolt connection on the 1800 cylinder?