Clutch Doesn't build pressure

[FalcoLion]

I have tried to bleed my clutch today but it looks like my clutch master cylinder gave up the ghost. I haved no idea why it would happen becuase the bike has barely 2300 miles on the clock. I have tried to bleed it but the clucth master cylinder behaved like it wasn't there. I had installed Speedy Bleeders (one way bleeder that doesn't allow air to com in) but by pressing the clutch nothing happened. I am sure you all know how the proper clucth feels. You get somewhat of a resistance. My master cylinder acts like there is something broken on the inside. No matter how I pushed on it it wouldn't build any pressure and would not bleed. For anyone thinks that I didn't opened bleeder valve I can say with 100% certainty that I did. Brake fluid was coming out under its own weight but wasn't pumped by Clutch MC.

 

So here are few questions.

 

1) Does anyone have any idea what it could be and how I should go about fixing this problesm.

2) Is there a Brembo rebuild kit for Clutch MC? If there is one does anyone know kits part number?

3) We all know that our bikes use same levers as older Ducaties. Would it be safe to assume that Clutch MC are same as well?

 

Any help will be appreciated.

 

I want to ride this f*ing bike but problems persist

 

Someone please help!!!

[gstallons]

Can you push fluid backward through the clutch master cylinder? With such few miles I would think there is trash in the piston bore or in the check valve portion of the piston.Anything can hold this back from working and give you fits. If you are afraid to disassemble this I will be glad to help. Also please keep ypur posts together and not on two or three different places.

[belfastguzzi]

It's unlikely that it needs rebuilt.

 

Was the clutch working before you started this?

Is there still fluid in the reservoir ok?

Is the lever adjusted properly and pumping the reservoir ok?

[FalcoLion]

It's unlikely that it needs rebuilt.

 

Was the clutch working before you started this?

Is there still fluid in the reservoir ok?

Is the lever adjusted properly and pumping the reservoir ok?

 

1) Yes it work just fine before.

2) Lever was adjusted properly

3) Now I took the fluid out but when I was trying it had plenty of fluid. Right to Max line

 

The only thing that is different now is that I changed handlebars. That should not have created any problems

[BRENTTODD]

Were you pumping the lever really fast and foamed the fluid. Thats why no restiance on lever

[OldButNotDead]

In a nutshell it sounds like:

 

It was working fine.

Then you opend the reservoir and bleed screw and did some pumping.

Then it wasn't working.

Now you have unhappiness.

 

The simple interpretation is that you've got air where there should be only brake fluid. Although many people seem to prefer pumping till turgid, my experience is that a good suck is more efficient (and satisfying).

 

Get yours here: http://www.eastwoodco.com/jump.jsp?itemID=...temType=PRODUCT

[BrianG]

Can you push fluid backward through the clutch master cylinder? With such few miles I would think there is trash in the piston bore or in the check valve portion of the piston.Anything can hold this back from working and give you fits. If you are afraid to disassemble this I will be glad to help. Also please keep ypur posts together and not on two or three different places.

 

This is often the answer. An air bubble gets trapped in the master cylinder and will not pump out. Set the bars so that the master cylinder's intake port is the highest point of the unit. Suck out the reservoir and force brake fluid back up from the bleed nipple. Tap the master cylinder with a plastic/wood screwdriver handle as it flows..... sometimes this will displace the bubble.

 

Protect the adjacent paint finishes from errant brake fluid. It is nasty stuff.

[Guzzirider]

Just to add to Brian's comments you can also tap the top banjo bolt where air bubbles can linger.

 

Be persistent 'cos it can take a while- better if you have two people sometimes, one to pull the lever in and out, and one to hold the hose on and open and shut the bleed valve.

[stormsedge]

Or, you could loosen the clutch cylinder mount a little so you can change the angle of it...maybe loosing the air bubble in the process. I had a heck of a time getting my clutch cylinder to build pressure when I changed the line for the handlebar risers, but eventually it did. (Btw, to get a proper bleed on the brake system of my 79 Guzzi, I had to move the rear brake caliper to get the air out. k

[Tom M]

In a nutshell it sounds like:

 

It was working fine.

Then you opend the reservoir and bleed screw and did some pumping.

Then it wasn't working.

Now you have unhappiness.

 

The simple interpretation is that you've got air where there should be only brake fluid. Although many people seem to prefer pumping till turgid, my experience is that a good suck is more efficient (and satisfying).

 

Get yours here: http://www.eastwoodco.com/jump.jsp?itemID=...temType=PRODUCT

 

 

After years of pumping levers I finally bought a Mity-Vac when I couldn't get my front brake MC to bleed after installing new brake lines. I should have bought one years ago! It works fantastic as long as you put teflon tape on the bleeder screw threads. It's the best tool that I've bought in a long time.

[Dan M]

 

After years of pumping levers I finally bought a Mity-Vac when I couldn't get my front brake MC to bleed after installing new brake lines. I should have bought one years ago! It works fantastic as long as you put teflon tape on the bleeder screw threads. It's the best tool that I've bought in a long time.

 

 

Like Tom says and be sure to keep the reservoir from going empty. Mityvac is the way to go especially for home use. There are also devices that push fluid backwards through the system (uphill) that work even better but are more costly. Phoenix Injector is one I use.

 

Motorcycle clutch and brake master cylinders are of such low volume that pumping the lever is usually just moving the air up and down in the line.

[FalcoLion]

Looking at all the suggestions I see that most of you think its an air bubble stuck in the system. I really doubt about it. The reason I doubt is because I have Speedy Valve installed which is a one way valve. It lets the air and fluid out but doesn't let air in. When you are bleeding brakes or clutch and pumping I would assume (correct me if I am wrong) that it should start moving the fluid and air out and build the pressure. Unfortunately its not the case. No matter what I do (short of gettin Mitty Vac) there is no pressure.

 

Any other suggestions?

 

Thanks

Vlad

[Baldini]

....When you are bleeding brakes or clutch and pumping I would assume (correct me if I am wrong) that it should start moving the fluid and air out and build the pressure....

 

Excuse the obvious....but you are closing the bleed nipple?

 

KB

[Dan M]

Looking at all the suggestions I see that most of you think its an air bubble stuck in the system. I really doubt about it. The reason I doubt is because I have Speedy Valve installed which is a one way valve. It lets the air and fluid out but doesn't let air in. When you are bleeding brakes or clutch and pumping I would assume (correct me if I am wrong) that it should start moving the fluid and air out and build the pressure. Unfortunately its not the case. No matter what I do (short of gettin Mitty Vac) there is no pressure.

 

Any other suggestions?

 

Thanks

Vlad

 

To verify if your clutch master is pushing fluid, remove the line at the master, put your thumb or finger over the hole with enough pressure to allow fluid to pass when you squeeze the lever but then not let air back in when you release. After a couple of squeezes on the lever you should not be able to stop the flow with your finger. If the flow is sufficient to push past your finger when you squeeze the lever, the master is probably OK and there is a line full of air like has been suggested.

Be sure to cover painted surfaces in case the master really is good and it squirts fluid!

[badmotogoozer]

Did you grind the internal end of the speed bleeder flat before installing it? If not was it difficult to get it to close? I did this and buggered my slave cylinder. If the level of your M/C drops as you pull clutch repeatedly there is a good chance the body of the slave cracked, and that is where your pressure loss may be. There is a little round ball bearing the original bleeder seats against that won't allow the speed bleeder to seat.

 

Compare the internal profile of the stock bleeder with the speed bleeder and you'll see what I mean. Grind the speed bleeder to match and it should work provided the slave isn't cracked.

 

Of course if you have already done this, ignore...

 

cheers