Mysterious brake parts?

Accidentally mixed some brake parts up and now I've got a piece I can't identify...hoping someone can help!

It's a super thin washer that should fit somewhere on the piston for the front master cylinder of my 1980 kz1000 (I think). It fits perfectly between the primary cup and the retainer for that cup (on the spring end of the piston), but I can't slide the piston into the cylinder with it installed this way. If I install it on the side of the primary cup opposite the spring, piston will slide into the cylinder but I'm not getting any pressure when bleeding the lines.

Parts fiches, manuals and K&L rebuild kits do not account for this washer....for the life of me I can't remember where it goes.

Any ideas?

Is it number 5 in this www.partzilla.com/parts/search/Kawasaki/...A2-A2A%29/parts.html

riturbo wrote: Is it number 5 in this www.partzilla.com/parts/search/Kawasaki/...A2-A2A%29/parts.html

He's talking about the front master cylinder
Pete

Do you see it anywhere on this parts diagram, & do you know if you have the stock M/C , or is it an aftermarket one ? let us know
Pete
www.google.com/url?sa=t&rct=j&q=&esrc=s&...h3FuvgVCqLj4Lud3Ejgw

Sorry for the late response...here's what I've got. Wanted to take some pics to make it easier. I do have the stock MC for my bike, the G1 or Z1 Classic KZ1000.

It's a very thin washer....(they're sometimes called thrust washers)









The parts fiche diagram for my model doesn't show this washer in the assembly, and the manual doesn't mention it, list it in the parts list, or describe it at all. It fits perfectly in the spot I've marked here with a red arrow...between the primary cup and the head of the piston that cup rests against. (This diagram and the manual also say nothing about a retainer that fits on the spring end of the piston...that retainer is necessary to hold the spring in place).




The manual for the '79 KZ1000 A3A shows this next diagram and it points out something called the "non return valve"....it's number 6 in the list. This is the only thing I've found that appears to be referencing the little washer. That manual doesn't mention anything about the non return valve other than saying that brake fluid passes through it on the return stroke of the piston....the exploded diagram in this manual doesn't show anything being there.





My best bet is that the little thrust washer is what the manual calls a "non return valve"....I put it in the location those diagrams show for the valve, but no real pressure buildup when I bleed the lines. Brakes were functioning properly before I did the rebuild.

Did you try putting it together without that washer & see if it works ? maybe it's from the other brake parts that you said you got mixed up with
Pete

Yeah, I moved the washer around and no luck.

Finally bought a new master cylinder. Just put it on and still no pressure... :huh:

I haven't found any leaks in the braking components and no air bubbles are coming out from the line when I bleed it.

This one's got me puzzled. I'm thinking I may be doing something wrong when bleeding. Is there a trick to dual caliper bleeding that I don't know about?

You never mentioned the reason for rebuilding your M/C, were you having issues with the front brakes, or was the M/C leaking ?
It could be stuck/frozen pistons in the calipers that's preventing you from properly bleeding them
Pete

I'll use a tube from the bleeder and a container with old fluid in it. Crack open the bleeder and pump it till clear, then do the other one.
Steve

swest wrote: I'll use a tube from the bleeder and a container with old fluid in it. Crack open the bleeder and pump it till clear, then do the other one.
Steve

It's also good to start the bleeding process by bleeding the caliper furthest away from the M/C, ...meaning the left caliper, as you're sitting on the bike, ..It also helps if you have a helper gently tapping with a rubber mallet on the brake splitter, while bleeding
Pete

swest wrote: I'll use a tube from the bleeder and a container with old fluid in it. Crack open the bleeder and pump it till clear, then do the other one.
Steve

Steve, I bought a set of Speed Bleeders for around 10.00 , & they work GREAT, ..no need to open & close the bleeder nipple, just attach a hose to them into a cup with brake fluid open the bleeder & start bleeding till there are no air bubbles, & the fluid is running clear, then simply close the Speed Bleeder nipple ,& you're done
Pete

pete greek1 wrote: You never mentioned the reason for rebuilding your M/C, were you having issues with the front brakes, or was the M/C leaking ?
It could be stuck/frozen pistons in the calipers that's preventing you from properly bleeding them
Pete

The rear brake piston was locked up and when I took it apart it was filthy inside. I figured it would be a good idea to check the front system as well, because PO said bike had sat for a while. Thing is, front brakes were working great before I touched 'em. Calipers, brake line splitter, lines, everything clear and clean now.


I started with the right brake caliper, and I haven't tried knocking on the splitter. Also, I haven't been putting my bleed hose into a cup with fluid as Swest said. Maybe doing these things would help.