87 clutch bleed

[Pasta Burner]

@Condor  

Hey Condor, 

I’ve read through searching that you have a method and write up for clutch bleeding.  I have an 87 VR and want to flush out the old fluid.  Any chance you can help?  Oh I do have a mitivac if that helps too.

All opinions welcome of course.

 

thanks, Tom

[saddlebum]

4 hours ago, Pasta Burner said:

@Condor  

Hey Condor, 

I’ve read through searching that you have a method and write up for clutch bleeding.  I have an 87 VR and want to flush out the old fluid.  Any chance you can help?  Oh I do have a mitivac if that helps too.

All opinions welcome of course.

 

thanks, Tom

There are about four methods I like to use for bleeding depending on the situation. Here are three of them. The 1st method I wrote up for another member sometime ago. It is the method I use for bleeding the clutch most times. The 2nd method involves using a large syringe and third a mighty vac or similar device and an air tight catch container. 

1st Method

1st you will not feel the same resistance with a clutch, as you do with brakes. So do not let that difference
deceive you. These are the steps I recommend to bleed a clutch, If I don't have a vacuum tool on hand.
1. Crack the line loose at the master. Before you bottom out snug the line up as you continue to squeeze the
handle. Release the handle and continue until you see signs of fluid. ( Sometimes if the master was
completely dry such as a new one or after rebuilding, you may have to prime it. You can do this by
removing the line completely. cover the hole lightly with you finger and squeeze the handle allowing air
and/or brake fluid to escape from under you finger. Before releasing the handle clamp your finger tight
and slowly release the handle. repeat until most fluid comes out. At this stage it does not need to be
completely air free., your just priming the master ). Once you have done this reconnect the line to the
master and perform the procedure at the beginning of this step.
2. Connect a clear line to the bleeder screw, after braking it loose and making sure it moves freely, and run
it to the bottom of a catch container with a bit of fluid in it. This helps prevent sucking air back into the
system and makes it easy to observe for air in the fluid.
3. Crack the bleeder open at the slave and slowly squeeze the handle. when it bottoms out snug up the
bleeder and release the handle. Continue until fluid starts to come out of the bleeder ( it does not need to
be air free at this point ).
4. As you begin to squeeze the handle crack the bleeder open and then quickly close just before the handle
bottoms out while fluid is still coming out (Do not pump the handle). Continue until the exiting fluid is
air free.
5. Next squeeze the handle but this time leave the bleeder closed until the handle comes to a stop. Pause
and hold for a few seconds, (this allows air to come to the top near the bleeder screw) then quickly open
the bleeder and then quickly close it again while a bit of fluid is still coming out just before the handle
bottoms out. Again continue until the exiting fluid is air free.
6. Finally return to the master. Squeeze the handle until it bottoms out. Pause and hold for a several
seconds ( again this allows for any air in the line to rise to the top of the line at the fitting), then quickly
loosen bolt just enough to allow some fluid to escape but then quickly snug up the bolt before the
handle bottoms out and while some fluid is still escaping. Repeat until no air spits out.
7. When done fully tighten the bleeder and line retaining bolt.
PRECAUTIONS:
A)-During the process keep an eye on the fluid in the master and keep it topped up. I recommend not
letting it go any lower than 1/3 full because if the master goes dry your back to square one.
B)- Cover everything well with rags to protect bike from brake fluid and when bleeding the master at the
line use a rag to keep fluid from spraying every where allowing just enough of an opening to allow you to
observe the fluid for air. With experience you don't need to look you can hear the difference between
when the escaping fluid is air free or if there is air in it.
C)- NOTE: during the process you will not note a mention snug the bleeder and banjo bolt. this is
because during the process it is not necessary to fully reef them tight. Just be sure to properly tighten
them when you are completely done.
Finally there are other methods that work well such as using a vacuum tool at the bleeder or pressure bleeding,
some even recommend speed bleeders, all of which make the job However, assuming you are only working
with basic tools, these are the steps I recommend I have used this method on the side of the road and never ever
had to re-bleed the system afterwards.

2nd Method

In this method you are back bleeding. Using a a large syringe  fill it with brake fluid and force the fluid in through the open bleeder screw until fluid starts filling the master. (be careful not to over flow the master). Then before removing the syringe, draw back on the syringe just slightly to eliminate any air trapped around the bleeder within the slave and close the bleeder before removing the syringe. Finally while squeezing the clutch lever carefully crack the banjo bolt holding the line to the master to allow air to escape. Tighten the bolt before the lever bottoms out. Repeat until you can no longer hear or see air escaping.

3rd method

This method involves using a mighty vac. or similar vacuum device. 1st you need an air tight catch container with two hose connections. One connection should have a hose going to the bottom of the container. This is the one that connects to the bleeder screw. The second connection goes to the vacuum tool and opens just below the top of the container. build and maintain vacuum in the container as you crack open the bleeder screw. Be sure to maintain fluid in the master while doing this. When no more air is drawn out of the slave close the bleeder. Finish by bleeding the line at the master.

[SpencerPJ]

Only thing I might add, the first thing I do is suck the fluid in the reservoir out with a turkey baster and start off with a filled clean fluid reservoir.  

and

If you happen to get air in your line and it simply does not want to play nicely, I would tie the clutch lever to the handlebar and let it sit overnight.  Those air bubbles love to rise and disappear overnight. 

Good luck, changing my fluid is on my to do list as well.

Edited January 15, 2022 by SpencerPJ

[Pasta Burner]

And the bleed screw for the clutch is under the little rubber cover on the left side?

[saddlebum]

2 hours ago, Pasta Burner said:

And the bleed screw for the clutch is under the little rubber cover on the left side?

If it is still there.

[Pasta Burner]

10 hours ago, saddlebum said:

If it is still there.

It’s surprisingly still pliable too.