My 02'Roadie has 60K original miles. I do 110 mi back and forth to work every day. This is the first mechanical problem I've experienced with the bike. Last year my front brake lever was getting stiff so I bled and replaced the brake fluid, problem resolved. The problem just reocurred so I ordered a cylinder rebuild kit. I need some help putting the master cylinder back together. The Yamaha service manual isn't much help. The rebuild kit came with one spring, a seal, a piston, another seal, a boot and circlip. Its the another seal that I'm not sure about. While disassembling the cylinder the another seal was on the middle of the piston, which could have been the problem. I've tried to put the new another seal in the same position but it doesn't seem to fit and I'm concerned that it is not right. Can anyone that have ever installed a front master cylinder rebuild kit help?

I've re-built the front MC when I have it chromed.

I also remember having problems getting it back together and finally realized that I was putting the plunger parts in backwards.

Unfortunately I cant remember the order. Try the spring on the other side of the plunger where you now have it.

I do have the stock MC (I changed to a warrior MC) but unfortunately I will not return home until next week.

Sorry .... can't help much more than that.

Doc

http://images.powersportsnetwork.com/fiche/images/Yamaha/2002/Motorcycles/1090_frontmastercylinder.gif
Check this out...<br><br>Post edited by: Big Al, at: 2006/06/28 18:55

Thanks Doc and Big Al for your advise. Got r done! The local Yamaha shop service dept is backed up 3 wks so I did what any self respecting rider would have done. I sat at the kitchen table trying to put the thing together until it was done. At 1130 pm Wednesday night I was riding around the neighborhood in the rain. Here's how it works.
The seal goes on the middle of the piston. I used a small finger nail clippers fold out file. I put the tip of the file on the end of the piston and slid the seal on and up the file. This stretched the seal over the wide part of the piston and into place on the middle of the piston. It took 15 min. to find the right tool for the job. The real tricky part was installing the circle clip over the piston boot. Persistence paid off.
*** Hint when bleeding the brake after a cylinder rebuild. When you think you have all the air out of the lines with the cylinder cover still off actuate the brake lever a few mm, just tapping, and you'll notice air bubbles coming from the fluid inlet at the bottom of the reservoir. Continue doing this until no more bubbles appear. Then do a couple of more cycles of bleeding at both calipers and you've have brakes!!! DON'T FORGET to keep the reservoir filed while bleeding. Happy Riding.

&quot;installing the circle clip over the piston boot. Persistence paid off&quot;

Oh ya, I remember that ....

Doc

Firstly
Happy 4th of July to all

How often do you need to replace master cylinder?
I have 27grand and am taking a long trip. I read in manual that you should do it every two years.

Ron

&quot;How often do you need to replace master cylinder?&quot;



You don't need to replace the MC. Are you sure it doesn't mean the brake fluid?

Doc

No I do mean the master cylinder
I have been in a car where it has failed as a result no brakes.
On a motorcycle it it fails it is a lot more dangerouse.

The Manual
under brakes there is a note that says replace master cylinder every two years.
The cylinder does have parts that could wear out

Ron

To be exact it says every two years replace the inerworkings of the master cylinder and the calipers

Look under notes

Ron

You're correct, it says that in the owner's manual.

That's a new one for me.

Never changed the seals on any bike that I've had on a regular basis.

Could be something that Yamaha recommends to stave off law suits. You .&quot; know .... like &quot;This coffee is very hot and can cause serious burns.&quot;

Doc