1981 GL 1100 front brake master cylinder

Information and questions on GL1100 Goldwings (1980-1983)
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Joined: Wed Aug 17, 2016 7:08 pm
Location: Riversdale
Motorcycle: 1981 GL1100

1981 GL 1100 front brake master cylinder

Post by Kaydee »

Greetings all...I need advice on front mater cylinder, mine is fubar and I need to replace it. I ordered one from china or somewhere over there, but it is not working. I gave up on trying to fix it myself and have given the job to a pro now, but he reckons that the one i got is for a single disk and I need to get one for dual disc. Can anybody tell me what other bike master I can use as I am unable to source the original here in South Africa. Second hand wing parts are like hens teeth over here...

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Motorcycle: 1980 Interstate

Re: 1981 GL 1100 front brake master cylinder

Post by biguns »

I used a cheap 14MM piston bore from china for many years and it was a son of a B#&@% to bleed I probably should have soaked it in a bath of brake fluid first, anyhow it took three days of my spare time and patience to work but once working it was ok.
If you do have one with a 14MM bore it is close enough, cover your plastics and paint with a garbage bag and with it mounted in the correct position fill just a little then turn you steering to the right and make sure it doesn't spill out, keeping it there fill it to just about full and make shure the two little holes are covered with fluid then turn it to the left observing that the fluid stays in and the holes stay covered.
You see the trouble is with these Chinese ones is the angle of the reservoir is parallel with the handle where as the factory unit has an angle to counter the angle of the handlebars this keep fluid covering the tiny feed holes.
With my cheap one there was just enough fluid to keep the holes covered without letting the fluid spill out, I could have filled it with the wheel strait and tightened the cap but then I am relying of the cap seal to keep brake fluid from leaking and I just wasnt willing to trust the cap seal..
Long winded answer I know
I held the brake handle closed with a bungie or rubber band overnight a couple times seemed to help but bleeding it submerged in fluid would have been the right answer I think
I thought my stock master was fubar but just for the sake of finding out I bought a rebuild kit, took some 800 grit wet and dry made a brake hone out of a peg of wood and a slit for the sand paper and with WD40 as a lubricant honed it out till it looked decent then installed the kit and it works just fine.
There are plenty of Honda models that may work on your bike so long as they mount on 7/8 bars and have the same 5/8 bore you will see a 5/8 stamping somewhere on it , look at Honda's that came with dual disc and cruiser type bars for the right angle and bore if you are using cruser bars as the stock ones were, if you switched to strait bars there are more options.
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Re: 1981 GL 1100 front brake master cylinder

Post by DenverWinger »

Had to replace master cyl on my '80 1100 - the plastic reservoir was crumbling.

Went to a motorcycle junkyard and found a bike with dual front calipers and the right size handlebar. Bought that master cylinder for $10 or so and put it on the 'wing. Works perfectly.

Might have fun if I ever need to rebuild it. I forgot to note what model of bike it came from. I think it's a Yamaha master cylinder.... :lol:
A local inventor has figured a way to turn a sausage grinder backward to manufacture pigs. :lol:

♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:
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