Brake Caliper Piston Install ? ( Which way )

You guys have been helping me along on my Dual Brake disc upgrade on my 77' KZ1000A using LTD brake rotors and Single Disc Brake calipers off of my 77 and one from a 78' KZ1000. Both calipers pistons are 42mm.

I went ahead and ordered a New 5/8" Master cylinder so will start out fresh and see if I can get this Dual brake set-up working.

When I rebuilt both Calipers replacing the piston seals, I installed the caliper pistons with the solid end of the piston facing down and open end facing up which comes in contact with the back side of the brake pad.

Still couldn't get my brakes to work as my other Post reflected, so I reversed the caliper piston as suggested. Now the caliper piston's open end faced downward and the closed end faces up and contacts the back side of the brake pad. Still my brakes are not working but think I narrowed it down to bad Master Cylinder?

But the Biggest Question is "Which way are the Brake Caliper Pistons supposed to be in the brake caliper" ? Does it matter which way?

Yes notice the witness marks on your old pads.
Steve

Steve, That's just it the calipers didn't have any Pads ? This was a piece bike when I bought it and the spare caliper didn't have any pads either?

Also, the EBC brake caliper pads on the back side of the pad that rests up against the brake piston, has 2 raised nipples that i'm assuming had a backing plate of some sort mounted there? Mine didn't have any of these plates either?

kzdcw wrote: I installed the caliper pistons with the solid end of the piston facing down and open end facing up which comes in contact with the back side of the brake pad.

...That would be correct.

kzdcw wrote: the EBC brake caliper pads.....has 2 raised nipples

...They help to center and hold the pads securely in place.

That's right and there should be a anti rattle plate. It looks like a circle with part of it cut out. That's so the pad will sit slightly off angle to keep it from vibrating. I've run without them with no problems.
Steve

swest wrote: That's right and there should be a anti rattle plate. It looks like a circle with part of it cut out. That's so the pad will sit slightly off angle to keep it from vibrating. I've run without them with no problems.
Steve

Here's what they look like on the KZ650-C1. You can see the wear around the perimeter where the piston pushes on the shim. Ed

Mine look like that too.
Steve

650ed wrote:

swest wrote: That's right and there should be a anti rattle plate. It looks like a circle with part of it cut out. That's so the pad will sit slightly off angle to keep it from vibrating. I've run without them with no problems.
Steve

Here's what they look like on the KZ650-C1. You can see the wear around the perimeter where the piston pushes on the shim. Ed

Attachment BrakePadShim-2.jpg not found

...Ed, I hope you didn't take your brakes apart to get the photo.

Ok, know that we have determined which way the caliper piston goes, I have purchased a New Master Cylinder ( thinking I don't have enough brake fluid pressure to move the piston ? ). Now I can take the calipers apart AGAIN and re-assemble. Hopefully I can get these brakes to work.

kzdcw wrote: Ok, know that we have determined which way the caliper piston goes, I have purchased a New Master Cylinder ( thinking I don't have enough brake fluid pressure to move the piston ? ). Now I can take the calipers apart AGAIN and re-assemble. Hopefully I can get these brakes to work.

...Well, lets get to it then. Spring's already here!

Have this weekend off. Have taken everything apart again and will start over from the beginning and see if I missed something. Also purchased a Mityvac Brake Bleeder Kit and see if that help as well.

kzdcw wrote: Have this weekend off. Have taken everything apart again and will start over from the beginning and see if I missed something. Also purchased a Mityvac Brake Bleeder Kit and see if that help as well.

...A good shop manual might also be a good idea.