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Clutch master cylinder

Started by pj166, July 19, 2009, 01:04:03 PM

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pj166

Just getting bike out and I do not have pressure in clutch lever.  I bled line down.  Still no pressure.  Any help??

andyb

Bleed it again.

If you're not getting massive leaks (check the slave end on the motor for dripping), then you just have air.

The FJ clutch is notoriously nasty to bleed, though you learn how to do it better as you go.  Seems to me that I don't have problems bleeding it now, but I move the lever all of 1/2" at a time (seems to work best).


ozzstar

Quote from: pj166 on July 19, 2009, 01:04:03 PM
Just getting bike out and I do not have pressure in clutch lever.  I bled line down.  Still no pressure.  Any help??

After installing a rebuild kit for the slave cylinder, I used a hand held vacumn pump to draw out the air in the line to bleed the system.  They cost around $25-40 at the parts store.  Also works like a champ on pretty much any bike/auto brake system.

Have fun bleeding!

Ozz
(Glen)
1986 FJ1200
Delaware

FJmonkey

I recently rebuilt my clutch slave and master. The salve was leaking and figured if I was gonna break the system open, might as well get both done and not worry about when the master was gonna go. I used George's recommendation after attempting to bleed it by the clutch lever. I used a syringe to pull the fluid through the slave. The Teflon tape on the bleeder threads is a must. Now that I have done this once, I could bleed the clutch very quickly next time. Thanks George.   :good2:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

pj166

I used a vacuum pump-bleeder.  Worked great, no problem at all and a lot faster too.  Thanks for the suggestion.

wavygravy

Quote from: andyb on July 19, 2009, 06:54:26 PM
Bleed it again.

If you're not getting massive leaks (check the slave end on the motor for dripping), then you just have air.

The FJ clutch is notoriously nasty to bleed, though you learn how to do it better as you go.  Seems to me that I don't have problems bleeding it now, but I move the lever all of 1/2" at a time (seems to work best).


please elaborate- notoriously nasty to bleed! i have a new master installed slave is cleaned & honed appears ok , i cant build pressure no matter how much i bleed, is the problem that there is a air bubble in slave cylender thats hard to remove, or am i still missing something here? please help , draw from slave bleeder with vacum im hopeing that will work, are we trying to bleed till all little bubbles stop at master cylender? why so hard to build pressure?
safety tip #1, dont forget the toilet paper!!

FJmonkey

Can you see that a bubble of air is trapped the master reservoir? If you are not sure then double check the short rod that goes from the lever into the master piston. I re-bleed my clutch 3 or 6 times (used a syringe at the slave) and was ready to go ballistic when I stopped and looked for other causes. The lever felt weak and spongy, worse than before I rebuilt the slave and master. Reversing the rod reduces the travel of the lever and prevents the piston in the master from getting a full stroke. Once I flipped the rod around, I discovered that I had in fact bleed the system properly 3 to 6 times in a row. Might be a simple stupid thing but it was kicking my ass till I used my brain. Made me realize my brain might good for other things too...... :crazy:

If you are bleeding from the slave then it is also very important to seal the threads of the bleeder with Teflon pipe tape. Failing to do so will allow air to get sucked in through the same threads and the bubbles never stop.

Hang in there, you will get it fixed and back in the Kookaloo zone.  :empathy3:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

FJmonkey

I just saw this on FleaBay, might be helpful. Still need to tape the threads. The vacuum method keeps air from returning with out the check valve. Just another $0.02 of free advice.

http://cgi.ebay.com/ebaymotors/Yamaha-FJ1100-FJ1200-Brake-Speed-Bleeders_W0QQitemZ390106969697QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item5ad42ff661
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

the fan

In cases where I have difficulty bleeding I usually ensure that there are no air "traps" in the system and strap the lever to the grip with a zip tie. The next step is to head upstairs, grab a cold beverage and watch some TV. ( times out of 10 when I check it in the morning the air is out and I can move on to more entertaining jobs.

As a preventative I  strap down the brake lever with a zip tie the day before any track day or trip regardless of when I last bled the system. (2-3 times a year for fluid flush/bleeding) My YZF has a cable operated clutch so that is not an issue for me.

wavygravy

ok i have brand new yamaha master cylender, ive pumped & bled & twiddled till blue in the face, now im gonna tie lever back & go inside for the beverage thing & see if that works! i cant believe im haveing such a hard time getting this to work, if i put on a new slave whould i still have the same bleeding no pressure issues? signed befuddled!
safety tip #1, dont forget the toilet paper!!

andyb

Short answer is yes.  The FJ clutch system, once air is introduced, can be difficult to bleed completely.

Biggest thing to know is that you only have to move the clutch lever about 2cm per pull, past that you're likely wasting your time.  It helps to change position, wiggle lines, and often it helps to simply walk away from it for awhile (particularly overnight), just don't leave the master open to air/humidity, cover it up.

delarbreavous

I rebuilt my slave cylinder this summer.I tried to bleed it with a syringe from the slave cylinder but nothing worked so I approched the probleme diffrentely, I inject the fluid into the system with the syringe from the slave cylinder so all the bubbles went up into the reservoir, moving the lever a little so that no air would be in the master cylinder and it worked!!! never touched it since.

Alain
Fluctuat nec mergitur

FJmonkey

Interesting, I would not think pushing the fluid up would work, but the air wants to rise, not go down. Good to know. I like ending the day smarter than I started it. Thanks.  :praising:
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

delarbreavous

Fluctuat nec mergitur

threejagsteve

Quote from: wavygravy on October 25, 2009, 02:09:42 PM
ok i have brand new yamaha master cylender, ive pumped & bled & twiddled till blue in the face, now im gonna tie lever back & go inside for the beverage thing & see if that works! i cant believe im haveing such a hard time getting this to work, if i put on a new slave whould i still have the same bleeding no pressure issues? signed befuddled!

I went through the same thing last June... I rebuilt the master, then saw that I also needed to rebuild the slave (couldn't tell before I had a good master ;) ).

It took a few days of bleeding to get all the air out of the system each time I had it open, but I finally got it good enough to work. However, I was puzzled most of the summer by the fact that whenever I rode it, I'd get air back in the line, and I couldn't find the leak. I finally figured out that I hadn't put enough sealant on the two long bolts that hold the slave on (I'd used a little, on the threaded part, but apparently not enough).

If you had the slave off to check it, you probably need to reseal those two bolts. I used Permatex # 2, two smallish beads 180* apart all down the length of each bolt, then twisted each bolt as I slowly put it back in to spread the sealant around the diameter of the hole. Thus far, that has seemed to work.

HTH...

Cheers, and the duck says, "Kookaloo!"
"If you wanna bark with the big dogs, you can't pee with the puppies!"