TOPIC:

I have a 77 kz900 that I am rebuilding the front caliper on. I can not get it back together for the life of me. I have tried assembling it with the piston fully seated (using c-clamp) but the caliper holder cant be put in when I do it this way. Can somebody shed some light. Also attaching a picture of my piston. Is this normal? Also should I get a new one since it is slightly pitted? I cant find any new ones online.

You can buy new pistons from Z1E. Yours is pitted on the outside and I would trash it.

There should be an O ring inside the cylinder. Remove it and make extra efforts to ensure there is no dirt in the O ring groove. It should be absolutely clean before replacing the O ring. Before inserting the piston you should make sure both holes into the back of the cylinder are clean. Blow air into them from the outside.

Once the piston is back in place you can replace the dust cover and the steel ring holding it.

When installing the caliper on the wheel I put it over the brake disc, using a screw driver to hold the pads apart. Once on the disc I move it into place to be bolted down but I install the brake line first...then bolt the caliper in place. I find it easier to install the brake line if there is some play on the caliper.

I will give z1 a call to get a piston ordered up.

Am hoping a new piston helps with my issue of not being able to assemble.

The caliper floats on the bracket. Take the two bolts off and clean them as well. Replace the O rings.
Steve

Everything has been taken apart and thoroughly cleaned. Got the caliper rebuild kit which has all new rubber and o rings.

The sequence I described in my last post wasn't correct. After installing the piston, next is the metal ring. Place on the outside edge of the cylinder and tap it lightly, but not all the way into the cylinder. Then install the dust cover and then tap the metal ring all the way into the cylinder.

Attached photo is a Z1 brake with piston installed. It's not identical to yours but it should be similar.

The most common cause of the piston not fitting into the cylinder is dirt behind the O ring in the cylinder. When I rebuild them I use a pic to scrape around the edges to remove any dirt. The other thing that can build up there is dried brake fluid that needs to be removed. It's not easy to get in there but a few minutes with a pic and a toothbrush will do the trick.

I wish my caliper would split instead of being cast, that would make this easier.
Since my piston is pitted I will be ordering a new one, but Z1enterprises does not carry the piston I need. The only company who has any is HVCcycle. Has anybody heard of them or had any experience dealing with them? hvccycle.net/kawasaki-brake-caliper-piston-43048-006/

Bama704 wrote: ......... The only company who has any is HVCcycle. Has anybody heard of them or had any experience dealing with them?

I bought from HVCcycle several years ago, and I was very pleased with their service and prices. Ed

Still working on this damn caliper. I can get the hanger bracket mounted in one direction no problem, except for it's in the wrong position. My caliper is in front of the fork tubes, so when I try to install the hanger bracket in the correct orientation, it is impossible to install. I am extremely frustrated. Any tips on this?

Pics hopefully to get somebody to have any ideas for me. Piston is fully seated.

Is the height of the new piston identical to that of the old piston?

This may be a dumb question; is the pad opening in the carrier large enough for the piston to pass through?

Can it be assembled if the carrier is placed in the caliper first, then the piston inserted through the back of the caliper, & through the carrier, then into the bore?

Good Ridin'
slmjim

It is the same height as old piston.

Also, not a dumb question. The piston will not fit through the opening, I have tried this about 20 different times all with the same result of me cussing of why it can't work.