Mystery master cylinder!

Hey everyone, but of a problem, my front brake lever has started sounding squishy and I've been finding worrying fluid running down the lever, although the sight glass is still full...I removed the lever today and gave everything a good clean, it all looks quite good and I pushed on the squishy piston a few times but couldn't see any fluid.....
Anyway if I find that I need to rebuild the master cylinder, I have a problem, my bikes a kz1000st but both levers are wrong and the master cylinder looks nothing like a standard st one, it kind of looks like a kz1300 one but I know a guy with a 1300 and it's not the same.... can anyone identify the master cylinder that I do have?! Thanks

I don't know. That type of m/c cap w Kawasaki painted on it was used over several years. Maybe an 83 GPz 550. Diagram drawing at Partzilla shows the sight glass on the same side as the handlebar mount (same as yours) & it has a modern style brake light switch. A few other master cylinders with the same cap are similar, including the 1000J, & a number of models used the same piston & diaphragm.
see x-ref at Partzilla by clicking the part numbers.

www.partzilla.com/catalog/kawasaki/motor...ront-master-cylinder

ps: before buying parts, I'd remove the cap screws & inspect the threads.

Thanks Martin I'll look into that and definitely check the screws it's strange ,the fluid seems to come from the bolt area of the handle and seep out of the ultra thin gap! Tomorrow I'll look for a part number on the master cylinder and see if I can't figure out what it is!

Those cover screws don't look stock. They may be bottoming out before the sealing rubber is getting properly compressed.

I was thinking a po may have installed SAE screws & messed up the threads. you never know sometimes.

Good catch guys! Has any Kawasaki ever used a straight slotted screw on a master cylinder cover? If so I certainly don't remember seeing one.

Rick H.

Hey thanks for all the input guys yes they're stainless screws from a previous owner but the pitch and thread is fine and the top is definitely clamped down tight ,since cleaning it all up I haven't seen any more fluid going down the lever yet but I'm keeping a close eye on it, I had a good look at the master cylinder today for any numbers on it but all is says it Tokico Japan and underneath 5/8 ?!

5/8" is the bore size. That's the standard size for most dual disk setups. Single disc is 14mm.

Cool thanks