rear brake issue, no pressure

[itjstagame]

I understand how brakes operate, they're simple enough. When I first got the bike I installed braided stainless lines so I have definately bled a line that was completely filled with air. But last year my rear caliper locked up and after relieving the pressure the rear pedal did nothing, so I got a whole new rear system off ebay (rear master, line, pedal assembly and caliper with pads even) but couldn't get that to work either. I replaced only the master cylinder at first, suspecting that, then tried the rear caliper as well, then tried every combination of both. Then unscrewed the brake line from the master cylinder and using my finger, pumped the brake pedal to see if I got any pressure or could move any fluid and I could not get any pressure from either. Should a master cylinder produce pressure if there's just a finger in the way (does it require any kind of pressure 'in front' of it to operate or something?). Or do I just have the luck of two bad master cylinders.

How do they work, are they rebuildable? I can't see how to pull the piston assembly and diaphram out to see what's inside and not working (like if something is just gunked up, etc), because I really don't want to shell out for another one just to find out that's not the issue either.

Any thoughts on what to test or do I just need a new master cylinder, thanks.

[StarGate]

I can't say that all mc's are rebuildable but all that I've seen were, providing you can locate a kit for them. With the line off of the mc and your finger blocking the the hole you should get pressure if you pump the pedal. Sounds like you have 2 bad mc's. You might try taking it apart and cleaning/inspecting the internals.

[itjstagame]

Yeah that was my thought. I can't figure out how to take it apart, can you give me any insight? I think I have to go in through where the pedal attachs, I've tried pushing and pulling and twisting and cutting the rubber diaphram... I'll just try buying another I guess...

Thanks.

[StarGate]

It looks like it comes apart on that end but looking at the breakdown on kawasakis site I can't see whether it's got a clip or whatever holding it together.

[StarGate]

Looking at the way that is setup on the bike I would think that if you disc the line at the mc then fluid would gravity flow out. If it doesn't you might have some trash in the line blocking the fluid from getting to the mc.

[itjstagame]

Yes, the inlet pipe gravity flows out very quickly, but it's just a straight pipe and I've verified it's free and clear an I get a lot of liquid through it.

Holding the MC veritcal in my hands with nothing connecting either pipe, I've filled up the input and outlet (they'll hold an ounce maybe each) and tried pumping and nothing. The input pipe never gets to the output they're sealed.