GS650 rear master cylinder

[Guest]

So the rear master cylinder on my bike has been frozen since I got the bike, so I bought a used one on eBay hoping to make 1 good one out of the 2. Should have known better....the eBay one is just as bad. I'm all for rebuilding one, but I've tried filling the bore with penetrating oil, as well as soaking the disassembled cylinder in Berrymans. Neither method has worked so far. Anyone have any tricks for this? Didn't know if heat was an option, or maybe compressed air (through banjo bolt opening maybe)?

[tom203]

So you can't move the piston in either m/c ? I'd try ebay again and hope for better luck this time ;how about ebay item#151249056245

sorta looks OK- ask seller if piston moves somewhat

[tkent02]

I have one for a 650 L if you are interested.

[Jcgonzal]

So you can't move the piston in either m/c ? I'd try ebay again and hope for better luck this time ;how about ebay item#151249056245

sorta looks OK- ask seller if piston moves somewhat

Unless I'm doing something wrong, yes neither pistons will move. I pull the rubber boot off, take out the circlip, and the yoke/rubber boot comes off in one piece. Once I'm in there it should be the piston, then the spring and spring, right? All I see once the yoke is off is a concave surface which I assume is the top of the piston; both master cylinders this surface is stuck in place.

I have one for a 650 L if you are interested.

PM sent

[Jcgonzal]

Still looking for one. Apparently there are only a few models that are compatible:



Alpha-Sports

- Part Number Cross-Reference - Where Used

Part Number or Accessory Name

1981 SUZUKI GS650GLX - REAR MASTER CYLINDER
1982 SUZUKI GS650GLZ - REAR MASTER CYLINDER
1982 SUZUKI GS650GZ - REAR MASTER CYLINDER
1983 SUZUKI GS650GD - REAR MASTER CYLINDER
1983 SUZUKI GS650GLD - REAR MASTER CYLINDER

[Jcgonzal]

Bumpin' this one up. I have quite a few parts from an 1100GK as well, if someone would want to trade. Engine parts, shaft drive parts, wheels, shocks, foot pegs, etc.

[Jcgonzal]

Bumping this one again. Been scouring eBay, can't seem to even find ONE listed.

[loud et]

Heck at this point spray it down with PB blaster again and wack it with a hammer to break the piston free. Work it in and out a bit and see if it comes out.
Don't have much to lose. Its already "junk" ....its Sunday....go fiddle around in the garaga

[tom203]

Took a while to find it, but I think I got one. See pic ( iPad mini is fighting me) PM me

[Jcgonzal]

Awesome, PM sent!

[tom203]

I did respond