Front Master Cylinder

I have overhauled my front calipers and replaced the brake lines, the master cylinder was new last year.
Right now can I easy push the brake handle 1/2, after that is harder and on 2/3+ its hard...

What is normal handling of the handle?
I`m feeling it should be harder... right now is identical to what it was before the overhauling...

I don`t know if I expressed me good here? hehe

Have you a single disk MC 1/2" (14 mm) or Dual disk MC 5/8" (16 mm)???

Here's an image of the front brake lever on my KZ650-C1 when squeezed extremely tight. Ed

Scirocco wrote: Have you a single disk MC 1/2" (14 mm) or Dual disk MC 5/8" (16 mm)???

Dual disc.

Then you have to bleed a little more air bubbles out of the calipers.

You might have to bleed the master too. I replaced the Brake Fluid on my C14 (I know different bike all the way around) I use a Mity Vac to remove old fluid which will drain the reservoir quickly if you are not careful which I was not. So I refilled the reservoir keeping a much closer eye on it and bled the calipers till the cows came home. I removed all the bubbies and still had a brake lever as you describe. Sometimes if one ties the brake lever tightly to the grip so the brake is applied over night, air will work it's way out of the little bleed hole in the master. After a night of that, the next day resulted with no difference in the lever. So I punted and bled the master. Ended up with a great brake handle with a ah ha moment.

when I replaced the caliper on the 900, I don't recall having a problem with the system using the Mity Vac. Must have been lucky....Good luck. Tin

You might want to try pumping up the hand lever and then squeezing as hard as you can, then strap the lever back against the grip. The idea is to create as much pressure inside the system as possible so the pistons move closer to the discs. Leave the bike with the lever pulled back for 24 hours and see if the lever firms up.

BTW, did you lubricate the caliper sliding pins with heavy duty black moly caliper grease?

Nsssism, I've often heard the process you describe above. When I've heard it before the cap was to be left of the master cylinder reservoir. Cap on or off make any difference?

Z1Driver wrote: You might have to bleed the master too. I replaced the Brake Fluid on my C14 (I know different bike all the way around) I use a Mity Vac to remove old fluid which will drain the reservoir quickly if you are not careful which I was not. So I refilled the reservoir keeping a much closer eye on it and bled the

calipers till the cows came home. I removed all the bubbies and still had a brake lever as you describe. Sometimes if one ties the brake lever tightly to the grip so the brake is applied over night, air will work it's way out of the little bleed hole in the master. After a night of that, the next day resulted with no difference in the lever. So I punted and bled the master. Ended up with a great brake handle with a ah ha moment.

when I replaced the caliper on the 900, I don't recall having a problem with the system using the Mity Vac. Must have been lucky....Good luck. Tin

How did you bleed the master cylinder?

Nessism wrote: You might want to try pumping up the hand lever and then squeezing as hard as you can, then strap the lever back against the grip. The idea is to create as much pressure inside the system as possible so the pistons move closer to the discs. Leave the bike with the lever pulled back for 24 hours and see if the lever firms up.

BTW, did you lubricate the caliper sliding pins with heavy duty black moly caliper grease?

Will try these over the easter.

Yes used brake high temp grease.

ajsfirehawk wrote: Nsssism, I've often heard the process you describe above. When I've heard it before the cap was to be left of the master cylinder reservoir. Cap on or off make any difference?

Doesn't matter.

Nessism wrote:

ajsfirehawk wrote: Nsssism, I've often heard the process you describe above. When I've heard it before the cap was to be left of the master cylinder reservoir. Cap on or off make any difference?

Doesn't matter.

If i understand these correct, when you have pressure on the line will the gravity force the air to go up because the weight of the fluid is higher then the air. In therey you will build over pressure in the resvoir by adding air when the cap is on.
But the pressure will have enoufg force to build some over pressure.