How do I get the Master Brake Piston out??

Purpose is to rebuild... But how do I remove the stopper??? Heat??? Brute pulling force??? I DON'T wan't to buy a new/used one. Or do I have to?


Post edited by: kawaduce, at: 2006/10/08 14:33

Post edited by: kawaduce, at: 2006/10/08 14:46

wrap a rag around caliper use compressed air blown through where brake line attaches to caliper.do not get your fingers near inside of caliper while you do this,thats why you wrap it in rag;)hold the presses,now we have a mastercylinder picture!:S

Post edited by: wireman, at: 2006/10/08 14:36

oops , i thought you were talking about the caliper. for some reason the picture didn' load the first time i looked at the post. disregard this post.:S

Post edited by: harm, at: 2006/10/08 14:40

wireman wrote:

hold the presses,now we have a mastercylinder picture!:S

Hits you in the back sometimes... But thanks for the effort anyway

No ideas on that rusty little stopper?

ifs its that nasty the bore is probably screwed also would be my guess.:S

wireman wrote:

ifs its that nasty the bore is probably screwed also would be my guess.:S

Yepp, probably true... But if I really want to find out? Since I have already bougt spares...:sick:

"Remove the retaining ring with retaining ring pliers (special tool), and take the stopper, piston, primary cup, spring, and check valve out of the master cylinder body. Do not remove the secondary cup from the piston since removal will damage the cup." From '79 KZ 1000 manual. YMMV.

Sounds like brute force if you can't just pull it out by hand. Can you get to the openings in the top bottom of the reservoir? You might be able to apply compressed air to the brake line port while holding a finger over the reservois opening to force the piston out.

I would love to find a retainig ring/clip, but alas, none to be found. As far as I can tell the stopper is just pushed into place, I can't see it's sitting in any goove or something. So... maybe brute force it is...:huh:

That is a different one than my 750 twin, but on mine, I used a blunt rod (gun cleaning rod, actually!) to push it out from the banjo bolt side, once I removed the plastic clip holding it in place on the lever side. Took a bit of force, not hammering, but just putting the cylinder on top of the rod, putting the rod on the table, and pushing the cylinder down onto the rod. Piston assembly popped up and out. Maybe put a rag around it so ya don't get gunky old brake fluid everywhere....

The master cylinder on my 77 650C was so gunked up that I couldn't see the retaining clip until I did a good bit of cleaning. My MC is different from yours, but I bet that there's a retaining clip there, and I bet brute force would only result in a damaged (maybe destroyed) master cylinder. On the plus side, I think yours is still available from Z1. but first I would try to get it as clean as you can and try to find the retaining clip. If you're sure that the clips are out, then try compressed air, and, as mentioned above, keep your fingers clear. Actually, you could try compressed air without risk. That wouldn't apply enough force to damage anything. However, hammering on the piston using a metal rod could.

Well, the banjo connection sits on the side of the bore, so brute-forcing from the end is not an option. I hope I can find / create some pulling device... My biggest worry is if the stopper somehow is slotted into the bore, or if the plastic clip is the only thing that's supposed to hold it in place. If plastic clip = pulling, compressed air and grease gun all becomes interesting options. If somehow slotted - hmmm...

Thanks for your thoughts this far!

Happy ending story...

To put it plainly: The stopper - a fairly thin spacer - does not sit in any goove. With a pair of pliers and a not so firm grip the piston eased out with no problemo.

I should probably never have asked this question :blush: but the Clymer said to let the workshop do rebuilding of MC, so from past not so uplifting experiences, I thought better to check first with people who know before I have a go myself. Well, at least: All is good! :laugh: