new front master cylinder.

[Parr8hed]

I was reading a thread here a while back about someone that had a NEW front master cylinder for sale. I am sure that is gone, but does anyone remember who had it just in case it is still there? I can't seem to find the thread.

My front brakes are so spongy right now, I have tried cleaning, bleeding, spooge hole trick etc. Do you guys typically have good luck with the rebuild kits? Oh yea, I also have the stainless lines.

I figured that now that my carbs are right, and she is running fast I should figure out how to stop her!

[randy]

Travis,

Parts n More has new aftermarket M/C for sale IIRC it's $70. If you're looking for the replacement reservior for your OEM M/C, contact John here on the forum, he had one for sale.

[don07tncav]

http://cgi.ebay.com/ebaymotors/ws/eB...category=35592

just poped up on e-bay and has a buy it now price.

[Parr8hed]

cool, have you used the rebuild kits with success?

[Ken Talbot]

Travis - a new master cylinder, or even a new reservoir for the M/C is not apt to make any difference. A rebuild kit might, but I wouldn't count on that either. If you have cleaned the system and put it all back together correctly with new stainless lines, your sponginess has to be because of air somewhere in the system. I know you say you have bled the system, but the sponginess means there is still air. Sorry....

[skippy344]

I agree with Ken

I replaced my lines with stainless and rebuilt the calipers Jan 04, rebuilt the master Oct 03 and I can damn near do an endo with my front brakes.

It had been a long time since I was able to lock up the front wheel, but boy howdy, I can do it now!

I removed the splitter behind the Yamaha emblem on the forks, and ran both lines right up to the master cylinder, and bleeding was a easier. Once I got all the air out, and let me tell you, it took FOREVER, The brakes tighened right up. I can't squeeze the brake lever all the way to the throttle grip anymore.

Even though I cleaned out my spooge hole on the master, my front calipers still squeal when I am pushing Scorpion around the garage. It still feels like they are holding the discs. I think the 25 years and about 5 rebuilds has finally ended the life of this master cylinder. I am going to go to a bone yard and yank one off of a newer Yammy, and see if it works. The key is to get one that drives two calipers. A new single caliper master won't really help.

Good luck!

greg

[ratbyk]

Brake Service

skippy344, your brake squeel while pushing the bike around the garage is most likely dragging calipers. Not the spooge hole. In many cases all you have to do is disassemble, clean everything in alcohol and reassemble. A smear of lithium grease (white) on the outer end /edge of the piston helps keep things free. No petrolium based greases.

Parr8hed, try bleeding in reverse. Get a new pump type oil can. Fill with brake fluid. Get a small length of rubber hose that will fit tightly over the end of the oil can and the bleeder screw. Remove most of the fliud from the M/C resivour. Connect the hose up and slowly pump fluid back up through caliper/hoses/Master until you have 1/2 filled the master. Move over to the other caliper and repeat. The fluid being pumped in will force air bubbles back up and out of system.
Another trick is to bleed the master on the bench before installing.
Another trick is to bleed before connecting up to the handle bar. Allows you to change the angle of the master cylinder bore (tilt) to allow air trapped in the M/C bore to seek out the hole to the line.
Do not bleed vigorusly. Brake fluid arrates very easily and will cause problems with air in system.
Ken/Sooke

[Parr8hed]

I think that I am just going to rebuild everything (m/c and calipers) then try bleeding again. If for nothing else just to make me feel better. I will try the oil can trick with bleeding in reverse and see what happens. I just recently had my carbs synched up by a local shop that seems somewhat reputable and I asked him to look at my front brakes and try to bleed them for me. His statement was that he feels like the m/c needs to be rebuilt. I know that I should take that with a lot of reservation, but I am just slowly trying to replace all of the 26 year old stuff that can fail on me. This is just another step in the process the way I look at it.

[randy]

Travis,

Yet another way to bleed that I've found effective is to unbolt the calipers from the forks and suspend them above the Master Cylinder.

Prop them up or hang them from the rafters, whatever works for you.

Fasten a wood block between the pads to prevent the pistons from falling out.

Bleed in the normal fashion with the lever. The elevation will alow the air bubbles to travel up to the calipers