Need help bleeding clutch

[slower than...]

I think my clutch is not fully disengaging.  Most likely air in the lines, and needs to be bled.  Don't feel comfortable riding it to the shop.  Bought a vacuum bleeder kit, but not confident doing the work myself (I'm about as mechanically savvy as a door knob).

Is there someone willing to come to the bike and show me how to bleed the system?  Bike is in Castro Valley.  Happy to buy you lunch or pay you for the trouble.

Thanks.

[desmoquattro]

I don't think I can stop by, but I'm happy to talk you through it over the phone. PM sent.

[EEL]

Friendly tip:

Autozone rents mightyvac's. Just pay the deposit and return when you're done. They'll credit back your account. I used to hate mightyvacs until I figured out how to seal them properly. After that it was a piece of cake. (2 items needed. Safety wire and teflon tape)

[Michael Moore]

Friendly tip:
After that it was a piece of cake. (2 items needed. Safety wire and teflon tape)

Good tip! Making the little fooker seal is always a pain.

[slower than...]

This is the kit I got:



Seems to have a bunch of different size fittings.  Do I still need a one-way valve?  What is safety wire?  And what is the teflon tape for?

I told you i was a klutz.

[desmoquattro]

Seems to have a bunch of different size fittings.  Do I still need a one-way valve?  What is safety wire?  And what is the teflon tape for?

I told you i was a klutz.

Ring me and I'll talk you through it.

[Michael Moore]

Well Joe will talk you through it, but for those playing the home game, here's how it goes:

You take the pump (brass thing with the red handles) and use some of the tubing to connect it to the reservoir (the white plastic cup with the two outlets on the lid. The pump tubing connects to one of the lid outlets (shouldn't matter which, they are both the same.)

Then you take another bit of tubing and connect it to the remaining lid outlet. This is the tubing that will connect to the banjo bolt you use to bleed your clutch.  You may or may not need one of the adapters to make a tight fit.

The banjo bolt looks something like this:



(although only the stuff from the nut-like part up will be showing)

The idea is that you create a vacuum by using the pump that pulls the fluid from your clutch system into the reservoir. (Without the plastic cup reservoir, fluid would go into your pump, and that would be a Bad Thing.)

The teflon tape and safety wire are, I'm assuming, to deal with the chronic poor seal formed by the various connections and hoses. You really want to be able to maintain a vacuum, and if the hose comes loose, or lets air in, well, it doesn't work all that well at all. I'm thinking you'd wrap the teflon tape around the banjo bolt (and maybe other parts if loose) and then you can twist safety wire like a mini hose-clamp.

Now the actual process of bleeding is a bit like rubbing your tummy and patting your head - all while dancing a jig. First, your goal is to get all the air out of your system, so it is key that you keep the clutch reservoir (on your left handlebar) filled at all times (but not sloshing over, for reasons I'll describe next).  Then, you will want to pump the clutch a few times and hold it, to build pressure in the system. Now, while holding it, you're going to loosen the banjo bolt and fluid will come out. If you're lucky, you'll see some bubbles! Now here's the key part. You need to keep pressure on the clutch lever for as long as the banjo bolt is open, even a bit. If you let go, there's a chance air will get sucked back into the system, (although that's what the Mighty Vac is supposed to prevent.) So close the banjo bolt, and you can ease off the clutch lever. Check the level in your reservoir, and repeat the "lever pump and hold, open banjo bolt, fluid comes out, close banjo bolt, release lever" cycle again. Do this a bunch of times and eventually you'll see one or more bubbles come out (or you run out of DOT fluid). Now, these won't be big soap bubble type bubbles, more like one of the bubbles in a champagne glass. Or smaller.

Now a word on DOT brake fluid. This is evil shit. If left on painted parts or plastic very long, it will start dissolving things. It is imperative that you have a very wet rag or three, and a bucket of water handy for wiping off the (almost inevitable) spills you'll have. Oh, if you have a painted garage floor, make sure that's wiped off too. Like I said, it is evil shit. I don't think it causes cancer or blindness, but I wouldn't be surprised if someday they find it does.

Oh, and one more thing - make sure you use the same number DOT fluid as is embossed on the top of your clutch reservoir. Don't mix 'n match.  And use a fresh bottle every time. Old fluid collects the water in the air (is hygroscopic if you like fancy terms) and water is No Good in your nice clutch system.

Hope that helps.

[EEL]

Side note, maybe I'm doing it wrong.

But when using the mightyvac I dont even touch the clutch lever. I just build vacuum an suck out the fluid after I make sure the seal is tight.

[mostrobelle]

Did you get your clutch bled? 

[slower than...]

Did you get your clutch bled? 

I've been too busy at work, which as you know, is a blessing in this profession, and in this economy.  I hope to see Joe today, to make sure I understand how it is done.  Then I will try it over the weekend. 

[Michael Moore]

Side note, maybe I'm doing it wrong.

But when using the mightyvac I dont even touch the clutch lever. I just build vacuum an suck out the fluid after I make sure the seal is tight.

Yeah, you're probably right. My mightyvac never worked all that great. But next time I'll try the teflon tape and safety wire trick.

[ScottRNelson]

I've been too busy at work, which as you know, is a blessing in this profession, and in this economy.  I hope to see Joe today, to make sure I understand how it is done.  Then I will try it over the weekend. 

Will you be getting hold of a MityVac?

I'll be happy to stop by with safety wire, safety wire pliers, and teflon tape on Saturday afternoon.  Once your clutch is good, I need to do mine too.

[ScottRNelson]

The teflon tape and safety wire are, I'm assuming, to deal with the chronic poor seal formed by the various connections and hoses. You really want to be able to maintain a vacuum, and if the hose comes loose, or lets air in, well, it doesn't work all that well at all. I'm thinking you'd wrap the teflon tape around the banjo bolt (and maybe other parts if loose) and then you can twist safety wire like a mini hose-clamp.

Okay, we did his clutch and my clutch and my front brakes, and I never did figure out how teflon tape or safety wire could improve things.

The only place that didn't seem to get a perfect seal was the connection to the bleeder valve, and safety wire didn't seem to improve things there.  I didn't try wrapping teflon tape around it first, though.

In any case, we filled up the container one and a half times.  Lester pointed out when fluid started to get sucked up towards the vacuum gun, and we dumped the fluid into a bottle for the next session.

I think the seals in both of my master cylinders (clutch and brake) probably need to be replaced.  How hard of a job is that?  Does it have to be done by a professional?  Who can do it if I can't handle it myself?

Anybody want to put on a clinic on rebuilding master cylinders?  I'll be happy to take mine off and bring as examples. 

[EEL]

Teflon tap goes on the threads of the banjo bolt. You need to remove it from the clutch slave wrap in and set in back in.

As for the safety wire, it secures the tube to the nipple. If you have a mighty vac you can ensure suction getting everything connected and then checking the gauge. If the vaccumm remains stable for 5 minutes your between the tube and the nipple is good.

The teflon tape ensure no air gets sucked in through the threads of the bolt.

[EEL]

Oh an and in regards to replacing the seals on the master. I had this same issue come up on my bike. I had a chat with the guys at Yoyodyneti.com

You can get a rebuilt kit from them but its about 30 bucks. Its hard to replace the seals an its a one time use only. If you dont get it right on initial install the seals cant be reused.

He suggested it was better that I just dish out the extra cash and by a new master for a hundred bucks.