Clutch reservoir/ Fluid

[naturbar]

Tried using the search for this info but came up empty. Can I use DOT brake fluid 5.1 in place of 4.0 in clutch reservoir ? I noticed while riding today that my reservoir level is low, it has never done this before. I have not yet checked for any leakage but will do so shortly. Also the clutch itself works perfectly, so apparently I've not introduced air into the line! Thanks for any and all assistance.

[Money Venture]

http://www.xs11.com/xs11-info/tech-tips/maintenance/brakes/23-the-great-dot-brake-fluid-controversy.html

[MiCarl]

Actually, 5.1 is different than 5. 5.1 is compatible with DOT4. Why you'd spend the extra money is beyond me though.....

 

**IMPORTANT**

Make sure you understand that plain DOT 5 is incompatible with (almost?) all other fluids and systems. If you mix DOT 5 with DOT 3, DOT 4 or DOT 5.1 there is a chemical reaction that causes sharp crystals to form. There is also the issue of compatibility of seals, lines etc.

[naturbar]

"Actually, 5.1 is different than 5. 5.1 is compatible with DOT4. Why you'd spend the extra money is beyond me though....." MiCarl I read somewhere about overheating the brakes and boiling the fluid, reducing braking power. So I thought I'd use 5.1 to get a little extra cushion... And I don't believe there is a significant difference in price. Also I had some 5.1 left over and thought I'd use it in the clutch reservoir.

[djh3]

Well depending on how long its been "left over" you may want to rethink you process. Brake fluid is notoriously bad for absorbing moisture from the atmosphere even if capped tightly. A pint of DOT4 from autozone is only about $5 And I can make a pint do a complete front rear and clutch bleed.

[naturbar]

Great input djh3.....thanks !

[BlueSky]

http://www.xs11.com/xs11-info/tech-tips/maintenance/brakes/23-the-great-dot-brake-fluid-controversy.html

 

Thank you for the interesting article!

[MiCarl]

BTW:

 

As the clutch wears the fluid in the reservoir will rise (opposite of brakes). You should leave plenty of room at the top (I like to put them just above the minimum mark).

 

If the fluid has gone down you've got a leak somewhere.

[naturbar]

BTW:

 

As the clutch wears the fluid in the reservoir will rise (opposite of brakes). You should leave plenty of room at the top (I like to put them just above the minimum mark).

 

If the fluid has gone down you've got a leak somewhere.

Should I see tell tale signs of fluid on my garage floor? What might be the most likely suspect of the leak?

[MiCarl]

Usual place for a leak is at the slave cylinder. The leak can be quite slow. It runs down behind the middle gear cover, above and behind the exhaust pipe. Depending on what the garage floor is like and how fast a leak is it could be hard to notice. 2007 is fairly new for a leaking slave though.

 

Monitor the reservoir. If it goes down you'll probably need to tear in to the slave.

[ragtop69gs]

My clutch slave leaked for 4 years and I never saw a drip of oil on the floor. Had to refill it twice a season until last year when it got more often, changed the slave & shift shaft seal while I was in there. Easy 3 hour job. No more fluid loss.

 

Sent from my SAMSUNG-SGH-I997 using Tapatalk 2

[naturbar]

Thanks MiCarl and Ragtop, when it warms up a bit I'll take a close look to see if I can detect any leakage. Btw when I was replenishing the reservoir, there was a fair amount of black sludge in there. I secured the clutch lever in and mighty vac'd out the fluid and cleaned it out. Then refilled it and clutch actuated normally. MiCarl you said the fluid rises as clutch wears, this must be a result of that? Although in this case the sludge must have accumulated before the level dropped. Thanks again gents for your inputs.

[MiCarl]

No, the black sludge is not from the clutch. It's because the fluid became water saturated and it precipitated out. It's from neglected maintenance. Clutch and brake fluid should be replaced at least every year, more often if it lives outside or it's a humid environment. You likely have it in the brake system too.

 

There is likely some of that crud (or worse) in the slave cylinder and the seal got damaged.

[skydoc_17]

Hey Buz,

MiCarl is right on the money with his comment. When water is absorbed into the clutch fluid, the oxygen is burned away due to the temps applied by the clutch and engine. The "black sludge" is actually carbon particles which are VERY abrasive. The first thing that happens is the slave seal allows clutch fluid to pass to the back side of the slave piston, so even though there is leakage, it never leaves the clutch slave housing. When the clutch slave housing fills up, THEN clutch fluid will start to leak out of the housing. (this could take months, or even years) I suggest you use a fresh pint of brake fluid every time you flush the brake and clutch system, which should be done YEARLY! Invest in a set of speed bleeders so you can do this service by yourself, and do it at the end of every riding season. If you neglect this vital service on the brakes and clutch, instead of a $4.00 pint of brake fluid you will be rebuilding/replacing brake calipers and clutch slaves.

Earl

[naturbar]

Earl thank you for this vey useful advice and great explanation. I do have speed bleeders and will flush both clutch and brake systems. Isn't this site just the best place to invest $12.00 !

And Freebird thanks for making it possible...