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Retired Pipe Polisher C2H6O+
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Discussion Starter · #1 ·
Anyone with experience in getting one of these to work?

Mityvac

As soon as I crack the bleed valve it just sucks air around the threads. I tried putting some Teflon tape on the threads but that just made a mess and didn't work at all. As soon as the oil hit's the tape it just comes loose.
 

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Last time I bled with the mityvac,. I sealed the threads with silicone grease. Also I put some vacuum on it with the valve closed and apply pressure to the lever before I crack the valve open.
 

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First, make sure you have a proper fitting hose. With the bleed valve closed, pull a vacuum with the pump. Squeeze and hold the brake lever, then crack the bleed screw open and the vacuum should pull out the fluid. After a second, tighten the screw and regain brake lever pressure. Repeat as needed. The trick is to be sure that there is always a vacuum before you crack the bleed screw.

I prefer the manual way for most brake fluid swaps. The only time I really thought the vacuum was helpful was when I completely replaced my brake lines.
 

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Retired Pipe Polisher C2H6O+
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Discussion Starter · #4 ·
I prefer the manual way for most brake fluid swaps. The only time I really thought the vacuum was helpful was when I completely replaced my brake lines.
That's what I'm doing now. Starting with new and dry everything. I was just hoping to get the majority of the air out and then finish up pumping the MC the old fashion way. I was just sticking the hose on the bleed nipple. Maybe I'll try one of the 90 degree fittings that comes with the pump to see if maybe I'm getting air around the hose fitting.
 

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That's what I'm doing now. Starting with new and dry everything. I was just hoping to get the majority of the air out and then finish up pumping the MC the old fashion way. I was just sticking the hose on the bleed nipple. Maybe I'll try one of the 90 degree fittings that comes with the pump to see if maybe I'm getting air around the hose fitting.

I just stuck the hose on the bleed valve. It will suck some air in around the hose, but it shouldn't be excessive. That may be what you're thinking is air pulling in from the threads. You should only be turning the bleed valve enough to let the fluid through, maybe 1/4 turn.
 

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That's what I'm doing now. Starting with new and dry everything. I was just hoping to get the majority of the air out and then finish up pumping the MC the old fashion way. I was just sticking the hose on the bleed nipple. Maybe I'll try one of the 90 degree fittings that comes with the pump to see if maybe I'm getting air around the hose fitting.
I always use the 90 degree fittings and never had an issue. As has been stated already, once you have the fitting on just pump the vac a couple of time to create the vacuum and away you go.
 

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Using the pump to pull a vacuum is problematic. Works fine for testing pneumatic parts. A very tight hose and as Slowdive said, grease on the threads improve it. A vacuum will pull fluid right past an air bubble in a pocket. The only way I am aware of is to either lower or invert the bubble zone or to flush fluid rapidly under positive pressure. In the shop, it's easy to fabricate a reservoir extension with a pressure nipple. Out of the shop, I carry a basic plate with some rubber bound to it and a nipple in the center. Pressurize it by holding down on it on top of the reservoir while pumping the MiteyVac in pressure mode. The extra bleed cylinder is not used. Crack the bleeder rapidly and briefly. Rinse and repeat. Keep the fluid up. A lot easier if you have a helper. Sometimes this works better that manually pumping the lever to pressurized because the bubble doesn't dislodge far enough to escape the pocket.

Positive fluid pressure prevents air from getting into the system. Never open the bleeder without pressure. Closing the bleeder without getting air into the slave with a vacuum setup is remote, IMO. For the same basic reason, self bleeders do not work well partly because of the milliseconds before the spring valve can close after pressure is removed but mostly because of leakage around the threads. In the case of self bleeders, grease is essential. I don't like them myself.
 

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Speed bleeders!!!

You could have saved some money and use the pump on your Personal Enhancement "Tool"...
Please Delete if you want too..
It is cold and I now know why bears hibernate...

http://www.mityvac.com/user_manuals/824381_revB.pdf

Real men don't read instructions...
 
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I always thought a vacuum pump system was for automotive use when you couldn't depress the brake pedal and open the bleeder at the same time. I never felt the need to use vacuum to bleed the brakes/clutch on my bikes. To each his/her own I guess.
 

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I think the mighty-vacs suck...or blow depending on the port UR using!

I also firmly believe that you can produce an equivalent or better vacuum with a hose and "container" by UR self. i'm talkin' 15 inches or more vacuum using UR mouth on a hose. And I ain't talking no suckin' biathces....
 

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I think the mighty-vacs suck...or blow depending on the port UR using!

I also firmly believe that you can produce an equivalent or better vacuum with a hose and "container" by UR self. i'm talkin' 15 inches or more vacuum using UR mouth on a hose. And I ain't talking no suckin' biathces....
Sigmund Freud would have had a field day with that post.>:)

Field day may well be an antipodean expression, so translating is "time of his life", "went to town" etc. and a whole year of interpreting what that really meant, even though it was a techo response.

I do wonder though, what on earth is a "biathces"?
 

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Oops - it was a typo. Meant to type biatches. just a weird way to type (and say) bitches
 

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I love my Mityvac. I just did all 3 of my bikes in one day (2 Ducati's and 1 Triumph)and it makes things much easier for me. As someone else said, I use the 90 deg fitting that comes with the kit and before I crack the bleeder valve, I make sure to build up pressure in the Mityvac.

I use it the same way this guy on YouTube does and haven't had any problems.

 

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So Mike, I know you're "prepping the Monster..."

I haven't read the entire thread, so I'm not sure "what" brakes your using. When I do the bleeding, I "think like a bubble" (they usually rise in a system). Have you seen my "no-bleed method" in the H.O.W.?

It may help near the end of your bleeding, to get rid of the nasty one that hides up in the banjo fitting. My method is much cleaner than trying to crack open and bleed the banjo fitting!

http://www.ducati.ms/forums/80-hall...removing-air-bubble-clutch-banjo-fitting.html
 

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Retired Pipe Polisher C2H6O+
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Discussion Starter · #15 ·
That’s some good suggestions. I bought the Mityvac hoping it would make things easier and quicker.

When my new rear caliper and lines get here I’ll give it another try using some the suggestions given here.


Sent from my iPhone using Tapatalk Pro
 

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You should get a tube of vaseline, put a bead of vaseline on the cap/bottle juncture to create a good seal.
Also put some vaseline around the bleeder threads, and a little in the 90 degree adapter.
This combination creates a good vacuum.

This is, or at least was in the instructions.
 

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I wouldn't recommend Vaseline. It's a petroleum product, and no petroleum should ever be near brake components. It swells/distorts the natural rubber that's used in the break system. That's why teflon tape around the bleeder threads is recommended.

Mike, when you get UR rear caliper, sometimes they get mounted inverted, with the bleeder on the bottom. If so, it's best to NOT mount it. Bleed it in your hand with bleed nipple "up". The other thing you need here is a dummy piece of metal to simulate the rotor being there, otherwise you risk popping a piston out of its bore when pumping the brake lever.
 

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Retired Pipe Polisher C2H6O+
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Discussion Starter · #18 ·
The Monster does hang the caliper under the axel. They also route the brake line in such a way that you can’t easily move the caliper for bleeding. I ordered my new brake line sized so that I can re-route the line in such a way that I can remove the caliper and hold it up high for bleeding.


Sent from my iPhone using Tapatalk Pro
 

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The Monster does hang the caliper under the axel. They also route the brake line in such a way that you can’t easily move the caliper for bleeding. I ordered my new brake line sized so that I can re-route the line in such a way that I can remove the caliper and hold it up high for bleeding.


Sent from my iPhone using Tapatalk Pro
Now THAT'S thinking like a bubble!
 

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The bleeders on most bikes are too short to seal the hose, the design is crap. If you can find some with bigger nipples they’ll seal better. I’m a fan of big nipples. Permatex #1 or 2, or anti seize compound to seal the threads. Use rubber line rather than clear plastic. Use a zip tie to hold the hose on the bleeder.
 
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