Issues bleeding the clutch

[sailor_chic]

One thought... simple physics. Air rises, so give it somewhere to rise to. JMO.

[gPink]

Rem how much air pressure are you running?

[B.D.F.]

One other thought- simple physics #2: surface tension. The tube diameter is too small (the internal ports) to all air bubbles to pass with such low pressure (read: without increasing the pressure greatly either by gravity or some type of pump).

That is why mercury gets stuck in little clots (technical word) in a thermometer tube and the nurse / technician has to whip it rapidly back and forth to create enough centripetal force to overcome the surface tension of the mercury against the tube walls. For those of you old enough to remember mercury thermometers.... although the physics has not changed :-)

Simple physics [fun fact to know and tell]: depending on the amount of wall creep and surface tension of a given fluid and the static pressure, the top shape of the fluid changes. That is called the meniscus and it goes both ways (Easy Boys!), convex and concave. Water makes a convex meniscus, which is why we can fill a glass with more water than it holds and the top of the water level is actually above the rim of the glass. Mercury makes a negative meniscus but when you fill a drinking glass full of the stuff to check, the environmental police will arrest you and take you away so now you have to just take my word for it.

Brian

One thought... simple physics. Air rises, so give it somewhere to rise to. JMO.

[B.D.F.]

Yeah, a vacuum aspirator. And by the way.... Thief! Thief! You stole Bernoulli's principle! :-)

I bought the same MityVac you give a link too but without the filler bottle for the reservoir. If you hunt around a bit they can be had for just under $100 (US).

And yep, they do make what is a tough- to- impossible job (ask Conrad :-)  ) job effortless and quick. Great for changing oil in small Honda motors too 'cause you can just stick a tube down the crankcase (Easy Boys!) and suck the oil out (I am not telling you again!). Honda oil drains end up barfing oil all over the machine they ride in / on in my experience.

Brian

I'm sure I've mentioned this before, but I use a home made vacuum system that uses compressed air. I use a glass Mason jar with bulkhead fittings and an SMC vacuum ejector (for 1/4" tubing iirc). For my suction line(s)...I have a single line for things like clutch bleeding, or I simply plug-in a tee so I can bleed both front calipers together or bleed both bleeder screws on a single rear caliper (many under-slung rear calipers have two bleeder screws).

I can bleed and refill a complete front braking system or clutch, etc in only a few minutes. One man job, no drama, no mess. However, even home made, it did cost me about $100 worth of parts/fittings/tubing, and you DO need compressed air to run it, but it does work very well.

I'll usually cut a piece of cardboard to fit snugly over a brake or clutch master cyl (if they're the cast aluminum ones, and not the round plastic bottles like on most sport-bikes). The cardboard is a splash guard. I can turn the vacuum on very slowly, and then just pour new brake fluid in the reservoir.

Now I understand that most people don't want to spend $100 bucks on stuff/parts for a powered vacuum system, but if you hate doing it as much as I did, it might be worth it...lol.

What I did was basically build a homegrown version of this:

http://www.amazon.ca/Mityvac-MV6835-Vacuum-Brake-Bleeding/dp/B0015POUXM

Rem

[Conrad]

One thought... simple physics. Air rises, so give it somewhere to rise to. JMO.

I tired turning the bike upside down but I was having a hard time filling the clutch reservoir. 

I picked up a MityVac yesterday locally (for even less than Amazon, $33). I'll be giving it another go sometime this weekend. 

[sailor_chic]

I see that my comment about physics has been shot down with a response that is backed my far superior education than mine. However, I will say, that the MICRO bubbles that I seen rise in the small tubes that I attached to my bleeders did allow the fluid and air to pass. I agree with what Brian has written, but I can also say that when I did this process, I was finally able to get my brakes to work. Mityvacs are nice, but I didnt have any results using mine. Good luck with your aggravation!

[Conrad]

I see that my comment about physics has been shot down with a response that is backed my far superior education than mine. However, I will say, that the MICRO bubbles that I seen rise in the small tubes that I attached to my bleeders did allow the fluid and air to pass. I agree with what Brian has written, but I can also say that when I did this process, I was finally able to get my brakes to work. Mityvacs are nice, but I didnt have any results using mine. Good luck with your aggravation!

Thanks for your suggestions, Nicole. My brakes are done and without drama. The bubbles that I'm seeing while trying to get the clutch bled are WAY larger than microbubbles. I'd be happy with those if that's all I had.

[Steve in Sunny Fla]

I use a pneumatic bleed from HF. cost around 30.00, It's made bleeding brakes a total breeze. I've done 4 c-14's by myself, clutch and brakes, full flushes, in just minutes. Cheap and 100% effective. Steve

http://www.harborfreight.com/brake-fluid-bleeder-92924.html

[B.D.F.]

Oh I do not know that my education is better than yours, perhaps different but not better- in fact, there is no doubt that you know many things that I do not- you can probably make one 'o dem sheep shank knots.

The method you used actually increased the pressure on the brake fluid by raising the reservoir level.

My irritation with the C-14 hydraulics actually peaked when I removed and cleaned the front calipers the first time. I just could not get the system to fill with fluid and finally put the issue to bed with an air powered MityVac power bleeder. And I can say with all honesty that while it was expensive (compared to 'pump and bleed' bleeding methods) it works fantastically well and I have used it for years now. Better than barbiturates at relieving annoyance IMO! 

Brian

I see that my comment about physics has been shot down with a response that is backed my far superior education than mine. However, I will say, that the MICRO bubbles that I seen rise in the small tubes that I attached to my bleeders did allow the fluid and air to pass. I agree with what Brian has written, but I can also say that when I did this process, I was finally able to get my brakes to work. Mityvacs are nice, but I didnt have any results using mine. Good luck with your aggravation!

[gPink]

Conrad, do we have clutch?

[VirginiaJim]

I'm not sure as he's been working on his wood....so he says.

[gPink]

Wonder if he's got blisters.

[VirginiaJim]

I should say so if he's been at it all weekend.

[gPink]

Could be walking funny too.

[VirginiaJim]

He best chime in soon or this is going to get worse...

[gPink]

Don't they make a pill for wood working problems?

[B.D.F.]

He is probably out looking for a job..... to pay for the biggest, shiniest and best automatic brake bleeding device known to man.

 

Brian

He best chime in soon or this is going to get worse...

[Conrad]

I'm not sure as he's been working on his wood....so he says.

Although I do have MASSIVE wood, I've finished with that, for now.   

Conrad, do we have clutch?

Why yes, yes we do have clutch!   

I ended up using the MityVac and the Motion Pro bleeder together. I was able to evacuate (I am NOT gonna say that I sucked the air out to this crowd) the air from the bottom bleeder with the MityVac but couldn't get any out from the top bleeder. I then hooked the MP bleeder to the top point and got a lil more air out that way then back to the bottom with the MP bleeder to get the rest of the air removed. I now have a very firm clutch lever.

Thanks for the help yous guys and gal.   

[VirginiaJim]

And thank you for the entertainment value that this has provided. 

I just now realized that there is another method you might have tried.  Using a syringe to push fluid up from the slave cylinder into the master.  I have one of those devices that I purchased just in case I needed it but haven't yet.
 

[B.D.F.]

The problem with that is that the threads of the bleeder itself leak. Not a lot but enough to make a mess. And it means you have to pump a fair amount of fluid at the system because most of it leaks by the bleeder instead of going through the system. And yep, Teflon tapes works to a degree but not 100%, at least every time I tried it.

Brian

And thank you for the entertainment value that this has provided. 

I just now realized that there is another method you might have tried.  Using a syringe to push fluid up from the slave cylinder into the master.  I have one of those devices that I purchased just in case I needed it but haven't yet.