Clutch bleeding down

[flsix]

Was on the way up to Tampa last weekend for a tech session with a group of VTX riders. Twenty five the first day and about ten the second day.All went well for the first 100 miles on the way up. Then sitting at a long light with the clutch in and tranny in gear the bike started to creep ahead. Tried to shift to neutral but now with a load on the clutch I couldn't get the shifter to move. Hit the kill switch, shifted to neutral, restarted the motor and shifted into gear with no problem.
Now with another 100 miles ahead of us I was just a bit concerned. At all the lights I shifted into neutral and the problem didn't happen again until we got to the shop. Just for grins I put the Phat Girl in gear and held the clutch in for about a minute. Sure enough she started to creep again.
Asked the shop owner (Michael Shepherd at Bucks Down Racing...yeah a little shout out) what he thought and he said to bleed the fluid again. He figured there was a piece of crud under the seal in the slave cyl. on the back of the tranny. The reservoir had grudge in the bottom so I used his power bleeder to clean it then bled the line and the slave and put new DOT 4 fluid in.
Fifteen minutes later I started the bike, put it in gear and held the clutch in for about two minutes with no problems.
Rode her all the way back home and a few times this week between the rains and all is well.
I guess with pulling all the fluid out while pumping the clutch dislodged the crud in the system and possibly saved me an unneeded tear down. We'll see how long this lasts.
I'm glad Michael suggested doing that before opening things up.
If anyone is experiencing the same symptoms try that fix first. It may just save the day.

[sandy]

Another step to add to your process is to fill the empty system with alcohol. Flush that through and then refill with DOT 4 and bleed. In humid places,(Naples) moisture will be absorbed by the alcohol and flushed out.

[Gryphon Rider]

Another step to add to your process is to fill the empty system with alcohol. Flush that through and then refill with DOT 4 and bleed. In humid places,(Naples) moisture will be absorbed by the alcohol and flushed out.

Brake fluid absorbs water, thus no need for the alcohol flush.

[jimmytee]

Another step to add to your process is to fill the empty system with alcohol. Flush that through and then refill with DOT 4 and bleed. In humid places,(Naples) moisture will be absorbed by the alcohol and flushed out.

Brake fluid absorbs water, thus no need for the alcohol flush.

That's what I was thinking. Brake fluid is hygroscopic I'd be concerned,  a little,  about introducing alcohol to my brake system..

[flsix]

I'd never heard of flushing the lines with alcohol to to absorb any water in the system. One of the reasons to change the fluid is to get rid of any moisture in the system, but I always got more than 18 months between changes.

[Steve K (IA)]

This has happened to me a few times over the years with both of my Valks.  It has always showed up when getting them out for the first time in the spring.  Pull in the clutch, put in gear and the bike jumps forward and dies.   I do a complete flush and all has been okay.  The same goes for the brakes...except this year on my I/S.  I was backing it out of the garage and pulled the front brake to just check it,  lever came all the way to the hand grip and bike didn't stop.  Instead of going for a ride,  I immediately bled the brakes until I got clear fluid with hardly any difference, so guess it's time to rebuild the master cylinder.  Waiting for the parts now. 

[Bone]

Steve K if it shows up in the spring maybe doing a fluid change when putting her to bed would help.
The moisture wouldn't be there through the cold season.

[sandy]

If brake fluid absorbs water, where does the water go: nowhere! It stays in the system. Flushing with alcohol absorbs water and flushes it out of the system. Then you add dry DOT4 fluid. I learned this trick from an old snowmobile racer and have done this in many vehicles for years now. No problems.

[flsix]

Steve we are lucky enough to be ably to ride all year down here so no long down times.


Sandy it sounds like it would be a good idea and I don't think it would bother any of the seals if it was all flushed out with the new fluid. I've just never heard of that before.

[Gryphon Rider]

If brake fluid absorbs water, where does the water go: nowhere! It stays in the system.

The water leaves with the old brake fluid when you bleed it out and replace it with new brake fluid.  But, do what you like.

[sandy]

Let me try to explain again. Not only does alcohol flush moisture, it also cleans the lines out. I just flushed the hydraulic clutch on a Jeep that hasn't been flushed in more years than the owner could remember. It took 2 flushes with denatured alcohol before the drainage was clear enough to refill. New DOT 3 or 4 won't dissolve grime out of the system.

[Skinhead]

Re build both the master and slave cylinders.  Bleeding will not fix a worn hydraulic seal, although the alcohol flush may help eliminate some built up crud.  The loss of hydraulic pressure is classic worn seals or scored cylinders.  If there is some minor corrosion in the cylinders, a brake hone or some fine wet/dry paper on a dowel rod can be used to resurface.

[Rio Wil]

I would be curious to ask if one feels the need to change the brake fluid in the Valk every year or two, does one change the fluid in one's car at the same interval.  There is no difference in the brake system components, ie, seals, fluid, cylinder materials, hose materials, metal brake ines.....  What makes the Valk more susceptible to absorbing moisture than the brake system in a car and necessitate changing fluid every year or two.

[Bone]

I have always changed my bikes every 2 years. Read somewhere 2 years was a good interval.
That made me feel guilty about my Jeep so I changed that one rainy day. I keep a paper log of
my bike maintenance (memory helper). Now I have started doing more to my Jeep and logging the details.

[Gryphon Rider]

I change my Valkyrie front and rear brake fluid and clutch fluid every time I change the front pads.  I put on 7000-9000 km per year, but if I put on more kilometres per year than I do (and thus wear out pads more frequently), I would change the fluid every two or three years.