Front Brake Master Cylinder 75 GL1000

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dartman1962
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Front Brake Master Cylinder 75 GL1000

#1

Post by dartman1962 »

I’m looking at replacing my 75 GL1000 Front Master cylinder with the NISSIN Complete
assembly.
Has anyone done so, if so which one is correct 7/8” 14mm or 7/8” 5/8” size
I tried asking Randakks site with no correct answer.
I am in Canada & don’t want to order the wrong one!
Also, has anyone gone & removed the splitter & gone to 2 single hoses from the Master cylinder
along with a NISSIN cylinder.
Any feed back appreciated!
1975 Honda Goldwing,
2000 Honda Ace Tourer
Let's R&R, Rev it up & ride!

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The day I purchased the loaded wing for the sum of $20.00. Nearly finished 1975 NGW way better naked!. My 2000 1100 Honda Ace Tourer. Next project?
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Re: Front Brake Master Cylinder 75 GL1000

#2

Post by Rat »

Scroll all the way to the bottom of the page for similar discussions …

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Re: Front Brake Master Cylinder 75 GL1000

#3

Post by gltriker »

-
I noticed this dimension underside the OEM front master cylinder on my 1975 GL1000.
-
20201010_182352_resized_1.jpg
20201010_182352_resized_1.jpg (29.8 KiB) Viewed 747 times
-
An 11/16 inches to mm conversion yielded 17.5 mm. I vaguely recall reading something about a 16mm front master brake cylinder being a reasonable substitute?
My trike's stock 11/16" front master brake cylinder works well enough to haul my trike down to a stop, by itself.
A 14mm unit wouldn't be even close. Pressure ratio and, most notably, inadequate fluid displacement volume.
5/8 inches to mm conversion yielded ~15. 9 mm.

I'd stick with the 11/16 inch front master cylinder.
hmmmm I was going to say I have strong hands, then remembered someone had removed the stock clutch and front brake levers and installed longer units. They might have been Magura branded levers?
Although they are longer, If you have short fingers they might not be a good substitute.

Yes, folks have eliminated the splitter.

also read this again
viewtopic.php?f=1&t=60494
Cliff (74yrs ;) )

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
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RE: a thorough fuel tank cleaning
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Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
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Re: Front Brake Master Cylinder 75 GL1000

#4

Post by low-side »

I run a stock m/c with braided stainless lines and am very happy with the stopping power and feel.
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Re: Front Brake Master Cylinder 75 GL1000

#5

Post by redglbx »

I too run the stock m/c and converted to the braided stainless lines earlier this year, one of the best things I have done to my bike, should have done it long ago ! Much better power & feel,, highly recommended !
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
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Re: Front Brake Master Cylinder 75 GL1000

#6

Post by dartman1962 »

Thanks for the replies!
1975 Honda Goldwing,
2000 Honda Ace Tourer
Let's R&R, Rev it up & ride!

Image Image Image
The day I purchased the loaded wing for the sum of $20.00. Nearly finished 1975 NGW way better naked!. My 2000 1100 Honda Ace Tourer. Next project?
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Re: Front Brake Master Cylinder 75 GL1000

#7

Post by dartman1962 »

I just got home & checked, mine says 11/16 on it too! So I guess now I either look for one or rebuild my old one!
1975 Honda Goldwing,
2000 Honda Ace Tourer
Let's R&R, Rev it up & ride!

Image Image Image
The day I purchased the loaded wing for the sum of $20.00. Nearly finished 1975 NGW way better naked!. My 2000 1100 Honda Ace Tourer. Next project?
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Re: Front Brake Master Cylinder 75 GL1000

#8

Post by redglbx »

Personally, I would clean & hone what you have, once the bores clean, look for pitting and if there is, then go looking for a good replacement. But quite frankly at that point if the oe is junk then I’d buy an eBay Chinese replacement with a 16mm bore unless you go all in and do stainless braided lines and then you can go with a slightly smaller bore m/c.

If you go replacement the good thing is that it’s all new, the bad thing is that it’s Chinese so it might be worthwhile to take it apart and clean it and inspect it and you can send it back if need be. Some have had mixed results with them. My .02
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
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Re: Front Brake Master Cylinder 75 GL1000

#9

Post by gltriker »

my opinion is this-
Braided lines, or not, In comparison to the stock 11/16th inch master cylinder (~17ish mm bore), a reduction in master cylinder internal bore diameter will require an even longer brake lever range of motion, every time, to firmly actuate the front brake calipers.
The OEM calipers are hydraulically fluid system volumes matched to the 11/16" master cylinder.
For some folks, each time you reduce the master cylinder bore dimension, an unnervingly longer lever stroke may be required as it gets closer to the handgrip to firmly stop the bike. :(
Cliff (74yrs ;) )

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^ :oldies

RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
"Can't see the paint when your looking thru the handlebars..........." -Oldewing ;)
"I'd rather Ride than Shine" -RAT tumb2 Me Too!!

Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
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Re: Front Brake Master Cylinder 75 GL1000

#10

Post by Shadowjack »

I just bought an anodized remote reservoir radial brake and clutch cylinder set for my GL10/12 project. They work fine. They say "Brembo" everywhere. On the box, on the paper inside, cast into the body. They cost around $100. Somehow, I don't think they really were made by Brembo. But if you didn't know how little I paid, you could be fooled.
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Re: Front Brake Master Cylinder 75 GL1000

#11

Post by gltriker »

-
dartman1962 wrote: Tue Sep 27, 2022 11:31 am I’m looking at replacing my 75 GL1000 Front Master cylinder with the NISSIN Complete
assembly.
Has anyone done so, if so which one is correct 7/8” 14mm or 7/8” 5/8” size

Any feed back appreciated!

dartman,
here's an informative thread, too tumb2
viewtopic.php?f=1&t=76634
Cliff (74yrs ;) )

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^ :oldies

RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
"Can't see the paint when your looking thru the handlebars..........." -Oldewing ;)
"I'd rather Ride than Shine" -RAT tumb2 Me Too!!

Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
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Re: Front Brake Master Cylinder 75 GL1000

#12

Post by redglbx »

I generally agree with Cliff’s opinion on all this. This is what I did (Bendix Brakes) for 20yrs and years ago Randall (Randakk) & I had a pretty intense discussion on all this in particular his 14mm m/c on the old CWC discussion list. I actually sat down & figured the displacement required to operate the front system and still have some lever travel left not up against bars.

The biggest disagreement came over my assessment of the flex in the calipers and the expansion in the lines which adds to the displacement needed. Several said that the lines and calipers don’t expand or flex which just isn’t true, there’s a fair amount of both and I measured the caliper flex and used some numbers on rubber flex line expansion for a known size & length from Bendix to figure the required m/c displacement & with the stock rubber lines the 14mm m/c was marginal at best. A panic stop would probably have the lever against the bar and not producing the optimum stopping power.

Anyway, that’s a very long winded response and quite frankly it’s your bike & your life,,,, enjoy !
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
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Re: Front Brake Master Cylinder 75 GL1000

#13

Post by Sidecar Bob »

There is some interesting information about selecting the optimum master cylinder for your needs here
https://www.cx500forum.com/threads/pick ... der.28670/

Re brake lines, the manufacturers of rubber lines recommend replacing them every 5 years (applies to all vehicles) so why would anyone even consider using ones that are 40 or more years old?
Re expansion of rubber brake lines under pressure, all you have to do is wrap one hand around a rubber line while squeezing the brake lever to prove that a significant amount of the braking effort is being wasted by the lines expanding.
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
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Re: Front Brake Master Cylinder 75 GL1000

#14

Post by gregforesi »

I bought a replacement GL1200 master that I got on E-Bay very cheap ($35??). The sight glass started to leak after about 2 years. I replaced it with the same piece of crap cuz heh, it's only $35.
Two years later the sight glass started to leak.
Being the cheap skate that I am, I took it apart, bopped out the site glass (plastic of course) and JB welded a dime in the hole. Now it's true that you can't see very well through a dime, but it only cost me $0.10 to repair the thing and that was 7 years ago. I did a brake fluid change and the interior of the master looked good.
This particular replacement master has a 14mm bore. It isn't touchy or finicky at all. I made my own lever by altering the stock GL1000 lever so the brake lever matches the clutch lever.
THIS ONE looks pretty close to the one I have and it's cheaper too! An added bonus is that when it starts to leak it only costs a dime to fix.
(The unit I have is silver. I didn't look hard but the only silver one I saw on Ebay was for 1" handlebars.)
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Re: Front Brake Master Cylinder 75 GL1000

#15

Post by Sidecar Bob »

Since the brake fluid level in the master cylinder is the easiest way to monitor the condition of the pads I don't think blanking the sight glass is the best idea.
When the sight glass in the eBay master cylinder on my winter machine started to deteriorate after a few years I ordered some sight glasses on eBay and replaced it when I had the system drained to rebuild the caliper (needed more often when you use it in the winter) and replace the fluid. I figure the the sight glass's life was just about the same as the brake fluid change interval (4-5 years with teflon/stainless lines) and changing the sight glass isn't difficult so changing both every few years makes sense. (This spring was 5 years since I replaced Mr.H's master cylinder (it got its new master cylinder later than Eccles) so it got a new sight glass & fluid as part of this year's pre-season work.)
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
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