totally stumped on master cylinder/bleed

[chocking]

Hello,

 

I've about had it....

 

Started out with clutch/ slave master cylinder and a stuck shifter problem...

Clutch and shifting problem seem to be pretty much resolved, but in trying to finish up the job I'm having a terrible time with the bleeding.

 

I've reverse bled the clutch about 5 times.Tried it the standard way several times, also left the clutch lever tied down overnight...

 

What happens is I bleed the air out, pump the clutch handle about 3-5 times and by then the pressure is so hard I can only move the lever about 1/2 inch. Rebleed and same thing......over and over and over...:bang head:

 

I've taken the master cyl. apart and put it back together twice...Followed the diagram exactly..same thing...Slave is new and work fine..... Push rod from slave works fine, clutch is good.....I've run a very fine wire throught the pinhole in the master cyl....

 

What the heck is the problem here???

 

I need some new answers or suggestions... I'm all out of ideas???

 

Clay

[CrazyHorse]

Im not sure what your exact problem is? Is it air?

[chocking]

I wish i knew... Seems to be pressure builds up in mc and will not release back into reservoir.. but there seems to be nothing wrong with mc

[Dano]

This is something I've been helping Clay with over the past week. We've (He!) has everything else working now and a great fundamental knowledge of these bikes now. Unfortunately, I've never done the master cylinder, so I cannot help him there. Slave works fine, clutch rod comes out the other side 1/4- 3/8ths inch when activated by mstr cyl. Problem is, when he first starts pumping, nothing. 3-5 pumps, it locks up under pressure past the master cylinder, and any fitting or bleeder loosened will alleviate the pressure build-up. We believe it is something in the master cylinder itself not allowing the pressure to return to the reservoir.

For once, I'm stumped!!!

 

Dan

[Neil86]

May have deposits in the line that are loose enough to act like check valves.

[mbrood]

You are experiencing hydraulic lock. And as you noted, any bleed of the line sets things right.

 

I know it's a pain, but it sounds like the master piston isn't going BACK far enough (relaxed position) to open the TINY pressure relief opening in the bottom of the reservoir. Pull the bolt and nut holding the lever and remove... this allows the piston to move BACK even more and that pressure should be relieved. If it is not, that tiny hole is plugged or the big spring on the end of the master piston is weak (never heard of that though). You should also be able to look in the lever end of the piston and it SHOULD be fully relaxed and flush with the circlip that holds it in the housing.

 

If pulling the lever DOES relieve the pressure you need to find out what's stopping the piston from relaxing enough to open the relief hole... mine was only happy when I filed a small bit off the flat end of the short pushrod between the lever and the piston. With mine on the bench, I couldn't "blow" back into the banjo bolt hole with the lever mounted, with new overhaul kit and clean parts.

 

The design is that, with the piston fully relaxed, it opens that TINY hole to the clutch line to the slave, releasing any pressure build up. This also keeps engine heat from heating and expanding the fluid while driving around and engaging the clutch (resultant clutch slip).

[chocking]

Thanks,

I have thought of that and that's why I made sure the little release pin hole was clean and open. The plunger does return to the completely back position against the clip. I'll double check again though.

[Steve S]

Clay

 

This may sound crazy, but you may have a hose that is coming apart inside and clogging the line when it has pressure on it. The way to check this is to pump the pressure up, then loosen the hose at the master cylinder. If a hose is clogged, the pressure won't come off. If the pressure does come off, please don't tell the Warden. She will just say "you were WRONG AGAIN"...

Good luck with it.

[chocking]

Went out this AM and took the master cylinder off again.........Took it all apart and re-did it...

 

made sure the little release hole was clear and that the piston was fully releasing.

I could blow air back thru the cylinder from the banjo bolt opening so the clutch appears to be fully releasing...

But... same thing happens... pump handle a few times and it becomes so firm that it can only travel a short distance ... and it will not engage the slave enough to push the rod.

 

( I have the clutch cover off and the rod only moves a fraction of an inch, yet the push rod works freely enough otherwise.

 

I'm about ready to haul it to the Yamaha shop, but I know how much that will cost, and I'm not sure they will know any more than the people on here....

[Condor]

You are experiencing hydraulic lock. And as you noted, any bleed of the line sets things right.

 

Way back when, when I had trouble getting my clutch working, Mike suggested taking the air hose and blowing out any crystals in the clutch line. So I blew the cr*p out of it, and did get some junk out of the line. It helped. The crystals will build up just beyond the bottom hole of the master and the banjo, and can act like a check valve. They can also get up into the cylinder, and even though you've cleared the relief hole out,they'll plug back up again. I know it's frustrating, and it's tough chasing ghosts. What finally worked for me is I removed the entire clutch system and reinstalled it by the book. After the wrestling match, and getting the thing to work, I was so happy I coulda spit.... Don't give up.....

Also when the pressure is up in the lines, and the clutch pack is released, you won't see much movement in the pressure plate as it's already extended as far as it'll go. Take the line off at the slave and the master, hold a rag over one end and blow through the other. Betcha you'll get crud out of the line.

Edited August 12, 2008 by Condor

[Captain Murph]

I have all these parts for an '83 or '84. If you suspect there is some flaw with a hose or the master cylinder itself, get in touch with me and I'll send what you need on a loan for troubleshooting.

 

Murph'

[chocking]

As soon as I finish a little late breakfast I'll take the lines off at the ends as suggested by Condor and the the crap out of them with the compressor....

 

Thank you all for your suggestions.

 

Murph.. If I get any further thoughts on what is wrong I may take you up on your offer.

 

Thanks,

Clay

[chocking]

Took of banjo at Master and slave... Blew the s____ out of it both ways.. No noticeable junk came out.. Blew the master thru the relief hole. Reverse bled the system, got a lot of air out.... and guess what..

 

Same situation.....Hydraulic lock if that's what you call it... Once system was pumped up, the lever is back to being too firm to hardly move.....

 

Hoses seemed clean and easy to blow thru even by mouth ( had to try it)

 

I've checked my master rebuild 3 times and compared it to the old one to make sure it was put in correctly.. all seems well except that the pressure is to great to even move lever..

 

Clay

[chocking]

Hello

 

After much profanity and ghost chasing, my hydraulic air lock issue seems to be resolved. After previously blowing out the lines once, I decided to disconnect the joint between the main clutch line and the black hose nearest the slave and blow that section separately .. walllllllaaaaaa.. gunk crap came out which I believe was acting as a blockage at that junction..Blew the Sh-- out of it.. reconnected all and bled well... Perfect clutch action.........

 

Now all that remains is to clean up one heck of a mess in the garage, fill with oil and fire up... hopefully I will be back rolling very soon..

 

Thank you VERY much to everyone who contributed ideas and suggestions.. Special thanks to Danob11 in Indiana and Condor for their well used suggestions..:bowdown:

 

This has been a fantastic learning experience in so many parts of this bike that I had not experienced. Hopefully I'll be able to use this experience to help anyone else that has difficulties in these areas...

 

 

Clay

[Condor]

 

This has been a fantastic learning experience in so many parts of this bike that I had not experienced. Hopefully I'll be able to use this experience to help anyone else that has difficulties in these areas...

 

 

Clay

 

Clay, you're now an official VR clutch Guru!!!!! Pass it on....

[chocking]

Well wait a sec.... All put back together and now there seems to be no power to the starter.. all I get is a dimming of the lights and nothing else.. Kickstand relay seems okay..

I must have messed up a wire or connection somewhere when I had the stator cover or some other part off... SHEEEEEET

 

First place to look???

[chocking]

Hey

 

Well wait a sec.... All put back together and now there seems to be no power to the starter.. :think:all I get is a dimming of the lights and nothing else.. Kickstand relay seems okay..

I must have messed up a wire or connection somewhere when I had the stator cover or some other part off... SHEEEEEET

 

First place to look???

[CrazyHorse]

Its always somethin isnt it. I have the same luck.

[Gearhead]

Check the kill switch.

 

Jeremy

[chocking]

It's somehow some way the neutral switch... It will turn over when clutch is held in......However I obviously have not gotten to the root of the entire clutch issue and the tranny still seems to want to engage ...

 

Still hoping for a cure sometime soon... looks like i'll be tearing the bike down again...