Front Master Cylinder Rebuild Kit (Piston Cup Set) - GS550E

[enriquev9]

I am restoring a 1978 GS550E. I want to rebuild the front master cylinder but can't find an available piston cup set from partzilla, ebay, etc.

Is there a suitable alternative (another mastery cylinder from another year) or a place to buy a piston cup set?

Any help is deeply appreciated.

[cowboyup3371]

I did some searching and yes, it’s not available at Parts Outlaw or a few others but it seems Alpha Sports thinks they still have it for about $50

https://alpha-sports.com/suzuki_parts.htm

You may have to redrill into the page for your bike as the link won’t paste correctly for me today.

Another alternative and one I did on my 550t is Salty Monk’s upgrade. Search on here for the information but it will mean you’ll need to change out the forks and steering stem. Advantage is that you’ll have newer brakes

[Nessism]

A brand new generic 14mm bore master cylinder can be bought off ebay for about $20 shipped. Master cylinders are simple devices that are hard to screw up so I'd go that route unless you are doing some faithful restoration and want the bike to be dead stock.

[enriquev9]

Thanks for the help and direction. I went ahead and ordered a piston cup set from alpha. I learned that it’s best to stick with stock during this restoration.

now let’s see if the piston set ships.

[Gorminrider]

A brand new generic 14mm bore master cylinder can be bought off ebay for about $20 shipped. Master cylinders are simple devices that are hard to screw up so I'd go that route unless you are doing some faithful restoration and want the bike to be dead stock.

as an aside, I've bought these before and used just its seals in the original. It was actually cheaper than a seal kit. and you get an extra micro-switch for the brakelight!