Disassembly of '79 GS850G front master cylinder

[sarathchandars]

Wherever I search, I get multiple tutorials for the rectangular master cylinder. But I have the cylindrical one. I attempted to try to disassemble it. Which I where I hit a roadblock. I couldn't nudge the reservoir loose. Anyone have directions on how to achieve this? Or should I switch to the popular rectangular ones?

[Nessism]

Remove the screws inside the reservoir, then the reservoir should come off. If it doesn't, there is likely corrosion in the O-ring groove.

[sarathchandars]

Yup it doesn’t move after the he screws are removed. I even tried to ‘gently’ turn it with increasing amount of force but it won’t budge. Any suggestion to loosen it up? Or just switch to a ‘new’ master cylinder?

[Big Block]

Did you get the piston out yet? If the bore has a divot corroded into it that could influence your decision. I've got 3 later Kawasaki M/C.s on my bikes.

[Burque73]

Dunk in boiling water? Kroil? Boiling Kroil maybe?

Just kidding. Good luck!

[1978GS750E]

If I remember correctly that reservoir is NLA, so be careful with it!

[dgates1]

It should wiggle out of there, but will likely be brittle so be careful. Getor (or Tourmax) makes a replacement, but they are not cheap!! It's the shipping now that will kill ya.

Search eBay for Tourmax RVR-302 or Getor GT-RVR-302

[sarathchandars]

dgates1 no amount of wiggling helped... It's just stuck. I'll try my best to get some WD40 into the gaps between the reservoir and the master cylinder body and if that doesn't work, switch to a 'new' one. Generally I agree that the reservoir isn't available or costs a million dollars or both.

[Nessism]

If you decide to move on, the Kawasaki Ninja EX650 master cylinder is a nice piece. Get the rectangular reservoir version, with a mirror lug. They are 5/8" bore, same as the stock Suzuki master for dual disc bikes.

https://www.ebay.com/itm/187591954737

P1010741 by nessism, on Flickr

[sarathchandars]

Thanks Ed. I am trending towards a Kawasaki master Cylinder now. While we are at it, can you please point me to a rebuilt kit as well for the Kawasaki version? Thank you very much!

[Big Block]

I bought a new piston and seals direct from Kawasaki this summer for a 650 Ninja front master.