Author Topic: Why Dual Bleeders? (Read 8270 times)

JerBear · « **on:** November 17, 2011, 07:19:58 PM »

There is a bleeder near the reservoir for the clutch and brake and another down on the caliper and clutch housing. The lower one makes sense but why the upper one? For the master cylinder?

stlheadake · « **Reply #1 on:** November 17, 2011, 07:22:12 PM »

You have to bleed the cylinder too....

VirginiaJim · « **Reply #2 on:** November 17, 2011, 07:40:27 PM »

I've never bled the cylinder, but I could see where you might if the system was dry.... otherwise, no.

DaveO · « **Reply #3 on:** November 17, 2011, 07:49:23 PM »

The more bleeders ,the better . Makes it SO much easier to get all air out .
Do the high bleeder last .

chi-gpz1100 · « **Reply #4 on:** November 17, 2011, 10:15:34 PM »

^^You sure about that? I would think you bleed the master first (just like in a car), then bleed the rest of the system.

Review pages 12-26 through 12-28 in the 2008 service manual (or similar if you got a newer model). Says to bleed from the top down just like I thought...

COGnosticat0r · « **Reply #5 on:** November 18, 2011, 03:07:25 AM »

When I changed to SS front brake lines at first I could not get a good hard squeeze on the brake lever and I kept bleeding and tying the lever over night to no avail. Then I noticed the bleeder on the master cylinder, bleed that and walla, back to the hard feel that I was used to.

Jeremy Mitchell · « **Reply #6 on:** November 18, 2011, 07:04:31 AM »

Quote from: COGnosticat0r on November 18, 2011, 03:07:25 AM

When I changed to SS front brake lines at first I could not get a good hard squeeze on the brake lever and I kept bleeding and tying the lever over night to no avail. Then I noticed the bleeder on the master cylinder, bleed that and walla, back to the hard feel that I was used to.

You could have just dropped one of your little blue pills in there to get the same effect.

So Cal Joe · « **Reply #7 on:** November 18, 2011, 07:07:34 AM »

Quote from: Jeremy Mitchell on November 18, 2011, 07:04:31 AM

You could have just dropped one of your little blue pills in there to get the same effect.

Yea, but that only last 4 hours!!!!!!!!

Jeremy Mitchell · « **Reply #8 on:** November 18, 2011, 07:15:31 AM »

Quote from: So Cal Joe on November 18, 2011, 07:07:34 AM

Yea, but that only last 4 hours!!!!!!!!

Only four hours?! Man I hope I never get old.

Sorry, back on topic. Start at the bleeder closest to the master cylinder..........

R Nelson · « **Reply #9 on:** November 18, 2011, 01:00:04 PM »

Don't forget you have two bleeders on the rear caliper too.

B.D.F. · « **Reply #10 on:** November 18, 2011, 02:17:41 PM »

It is easier to bleed the system if you can do smaller segments at a time. Also, by having one bleeder at the top of the system and one at the bottom, you can bleed all of the air out of the master cylinder without trying to pull that air and fluid down a couple of feet; bleeding works best when the fluid is trying to work its way up rather than down.

The hydraulic systems (clutch and both brake systems) on this bike are really tough to bleed once any air has gotten into the system. If the only job is to change the fluid then it is not too bad but once something is disconnected such as a fluid line, caliper, slave cylinder, etc, then the entire system needs to be purged of air and some of us have found it to be quite challenging. I highly recommend a powered vacuum unit to bleed these systems; they are not inexpensive (around $100) but they make a painful to impossible job fast and easy.

I will bring mine to COG tech day in MA next spring so anyone who wants to change fluid can show up with a can of DOT 4 brake fluid and have it changed.

Brian

Quote from: JerBear on November 17, 2011, 07:19:58 PM

There is a bleeder near the reservoir for the clutch and brake and another down on the caliper and clutch housing. The lower one makes sense but why the upper one? For the master cylinder?

chi-gpz1100 · « **Reply #11 on:** November 18, 2011, 02:23:34 PM »

Motive makes products for this. I got one for the car.

I've used vacuum pumps such as mity vacs in the past, but those are crap. Can never get a good enough seal on the nipple.

http://www.motiveproducts.com/

rcannon409 · « **Reply #12 on:** November 18, 2011, 02:24:15 PM »

I like the extra bleeders since it meant you do not need to send dirty fluid through the system when bleeding. Or as much, anyway.

B.D.F. · « **Reply #13 on:** November 18, 2011, 02:32:48 PM »

I agree about the hand pumps but the powered MityVac series are outstanding: http://www.mityvac.com/hq_images/MV7430.jpg

The type you show use pressure to force the brake fluid down through the system from the master cylinder by the looks- I don't know how you would adapt that to the clutch or brake master cylinder reservoir on a C-14. The MityVac unit uses compressed air to create a vacuum and pull the brake fluid down though the system still using the bleeder in the conventional way; the bleeder does leak around the threads somewhat but it just does not matter because there is ample vacuum and flow generated by the unit to still maintain a draw on the system. It really is effortless and it works very well.

The pressurized types will also work well but they do require adapters to mount to all different types of master cylinder. Two different would be required on the C-14 alone (one for the rear brake and one for the front brake and clutch).

Brian

Quote from: chi-gpz1100 on November 18, 2011, 02:23:34 PM

Motive makes products for this. I got one for the car.

I've used vacuum pumps such as mity vacs in the past, but those are crap. Can never get a good enough seal on the nipple.

http://www.motiveproducts.com/

chi-gpz1100 · « **Reply #14 on:** November 18, 2011, 02:40:07 PM »

Brian,

A universal adapter such as this could be used on the c14 or any other reservoir that's a non standard shape. So long as the top can be sealed to the reservoir, you're in good shape.

.

Consider yourself very lucky to have accessible compressed air in your garage. We don't have that here, so the hand pressurizer hand to do. Pumped it up to about 15 psi, then started at the rear of the car. It didn't squirt out, but did come out in a small stream. The fronts did bleed faster because the lines have a large ID. Went through nearly 2 32oz bottles to flush the car out. I imagine one or two 12 oz bottles should be enough for the bike.

Edit: Just caught your comment about the rear brake. You are correct. However, the rear is so easy to do on a bike, I wouldn't bother with a pressure bleeder or vacuum pump.

DaveO · « **Reply #15 on:** November 18, 2011, 02:47:27 PM »

Quote from: chi-gpz1100 on November 17, 2011, 10:15:34 PM

^^You sure about that? I would think you bleed the master first (just like in a car), then bleed the rest of the system.

Review pages 12-26 through 12-28 in the 2008 service manual (or similar if you got a newer model). Says to bleed from the top down just like I thought...

do it first, last or twice if you like. Whatever works. I just got very good results doing it at the end. Didnt know there was a writen procedure.

DaveO · « **Reply #16 on:** November 18, 2011, 02:56:34 PM »

ive used the mity vac and was not impressed . Maybe I wasnt using it correctly i dunno
I get best results just squeezing the lever and pumping everything downward.Helps to have an assistant to pump the lever and keep an eye on the fluid level
while i open/close bleeder and catch the fluid. This simple way always leaves me with good lever feel /no spongyness.

B.D.F. · « **Reply #17 on:** November 18, 2011, 03:15:23 PM »

Yep, that would work if you could seal it to the reservoir as you mention- the seal for the reservoir that is provided cannot be used as it is also the bellows to allow the fluid level to do down and would seal the system from the pressurized bleeder.

I have used positive pressure to bleed these systems successfully but I did it with a tapered tube held in place at the bottom of the reservoir neck. It worked well enough but is somewhat risky because if the plug should pop out while under pressure, it will spread brake fluid everywhere. Not a pretty sight.

Again, I have had significant difficulties getting any fluid to pump through a dry system on all three circuits on a C-14. Most of the time, no fluid flows into the master cylinders after the system is bled dry and so the process of bleeding will not even start, let alone finish. And if the system does bleed, it seems to trap small amounts of air and remain 'squishy' for days or weeks. Quite a few people have reported the same problems on this bike; I suspect the hole between the reservoir and the master cylinders are too small to allow a decent fluid flow. At any rate, the powered vacuum system has worked fantastic for me on my bike and everyone else's bike I have used it on. You are absolutely right in that it does require a compressor though so if one is not available, that system will just not work.

Brian

Quote from: chi-gpz1100 on November 18, 2011, 02:40:07 PM

Brian,

A universal adapter such as this could be used on the c14 or any other reservoir that's a non standard shape. So long as the top can be sealed to the reservoir, you're in good shape.

.

Consider yourself very lucky to have accessible compressed air in your garage. We don't have that here, so the hand pressurizer hand to do. Pumped it up to about 15 psi, then started at the rear of the car. It didn't squirt out, but did come out in a small stream. The fronts did bleed faster because the lines have a large ID. Went through nearly 2 32oz bottles to flush the car out. I imagine one or two 12 oz bottles should be enough for the bike.

Edit: Just caught your comment about the rear brake. You are correct. However, the rear is so easy to do on a bike, I wouldn't bother with a pressure bleeder or vacuum pump.

IRULE · « **Reply #18 on:** January 03, 2012, 10:23:03 PM »

Please help me understand the reason for dual bleeders. Please keep explanation easy and stupid.

If I am just doing fluid exchange for either clutch or front brake, I only need to use the bleeders on the bottom and not worry about the onces that are next to the reservoirs...right?

If I was to remove the calipers or any thing majors, then I should bleed from both bleeders (top and bottom)...right?

Did one of you saying that you can't bleed the clutch fluid from the case? What is the problem?

Thanks for the help.

VirginiaJim · « **Reply #19 on:** January 04, 2012, 04:23:22 AM »

Again...I've never used the bleeders on the master cylinders (brake, clutch). If you don't run them dry I don't see the need. I would only bleed the masters if the reservoir has run dry or are filling a dry system. I know the manual uses both top and bottoms in the procedure but I've bled the system multiple times without issues. This is not a big deal. Do what you feel comfortable with. I just hate extra work and what I've been doing works for me. This is the first bike/car I've ever had with bleeders on the masters. I think it's a good idea, though. Saves disconnecting the lines......I think.

Actually, it's more than dual bleeders....maybe tri-bleeders for the brakes. The front system has three bleeders. It's too cold to look at the rear system today but there's two bleeders on the rear caliper. Don't remember if the rear master has a bleeder...probably does.

To me, having a bleeder on the master itself is a convenience and aid in removing air from the master cylinder itself. It can be a devil of a job to remove air from the masters. I haven't had any air in those masters that I'm aware of so I haven't done anything to them. Maybe I haven't had any air issues because I haven't cracked them. All I can say is that I haven't used them. Ain't gonna use them (unless I replace them...not bloody likely).

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Author Topic: Why Dual Bleeders? (Read 8270 times)