Master Cylinder Help

[climber_dhl]

I have a question regarding the Front Break Master Cylinder for my GS850G (1980). My brake system was in pretty bad shape so I rebuilt the calipers. Next I ordered a rebuild kit for front Master Cylinder except when it came ( a week and a half later) it was the wrong one. I went to the store and returned it the manager had me look at the OEM kit for my bike to make sure it was the right one. And of course it wasn't. I look through my shop manual and the type of master cylinder I have does not match any of the years in my manual. If someone could help me find the part or at least tell me what kind it is (part number,or type/year of bike, etc...) I would appreciate it very much. I thought it might be an aftermarket part but the master cylinder looks like the oldest part on the bike and it is in really bad shape (hence why I am rebuilding it). Thanks for all you help.

[climber_dhl]

Piston Cup

Here is a close up of the piston cup set. Thanks

[BassCliff]

Here's a little something

Hi Mr. climber_dhl,

I saw a complete (used) front brake system for a 1980 GS850 on ebay. I sent you an email about it. I'm not familiar with the master cylinder in the picture. It's also possible to put aftermarket or other bike's master cylinders on these bikes too. Check with the experts for compatibility.

Thank you for your indulgence,

BassCliff

[Matchless]

The M/C could be from any make of bike. If you look underneath it it may have a stamp showing 1/2 meaning it is a 1/2 inch bore. You can reuse the piston and spring, but usually the rubbers are the culprits.
You really just have to replace the two rubbers seal rings on the piston and any kit that uses those can be fitted as long as they are 1/2 inch.

Try this site, they give you sizes and you may be able to match your size

http://motorcycleproducts.co.uk/catalogue/suzuki-master-cylinder-kits-c-108_296_398_1900.html?page=2&sort=1a

[Nessism]

That master doesn't appear to be the stock one. As long as the seals are not damaged, cleaning the master and assembling it back together often doee the trick.

[climber_dhl]

I need a new one though. The main boot on the piston is shredded. Recommendations?

[rustybronco]

My opinion get a good used "correct" one. at least you will know where to start if and when you need to repair it.
down side, you may have to get the lever for it also.
check the brake light switch, is it different than the clutch side?