NE1 use MITYVAC to bleed brakes?

Hope brake topics are ok here. Had a wierd thing happen while bleeding with my MITYVAC. I made a setup with a 1L hard plastic camping style water bottle with hoses going in and out to pull brake fluid into - worked great! BUT when I pulled some good vacuum on the bleeder screws, TONS of air came out, for as long as I pulled a vacuum. I freaked out thinking I had a busted line somewhere, since my fluid in my master cylider was not going down that much.
 
So, to rule this out I closed all the bleeders and pumped the pedal many times and it firmed up a little (never driven the truck before, so I didnt have a reference as to was "firm" was) No leaks anywhere. Did it again, no leaks anywhere.
 
My conclusion was that the strong vacuum from the MITYVAC was actually pulling air from around the threads of the bleeder screw and into the stream of brake fluid coming out of the screw making me think there was a ton of air in my system or a brokenline/leaking fitting.
 
Since driving the truck it stops great! Any one else have this happen? - Mike

Yup, you had a vacuum leak either around the threads on the bleeder or on the actual coupling to the bleeder.  I have a little hand operated vacuum pump for bleeding brakes and I have finally had enough of it and glued all of the connections together, using the smallest fitting on the end.  Then I take the bleeders right out and coat the threads with caliper grease and screw them back in.  Haven't had any more leak troubles since.

But that definitely sounds like what you experienced.

Air was def. coming out through the middle of the bleeder, so I will try the caliper grease on the bleeder threads next time. Thanks for the tip! - Mike

That's a nice way to bleed the brakes by yourself!
 
I just usually have someone press the pedal and loosen/tighten the bleeder screws as needed, lol.

Yup, that's what I do when I have helping hands (and feet).  Sometimes it doesn't work out that way so I have to take different approaches.

Beer is a great motivator to get people to help in the garage! lol.
 
But yeah, I know what'cha mean... Probably better using the vacuum thing than moving the seat all the way up and using the a chunk of pipe to hold the pedal down...