Compressor requirement for MityVac bleeder

[ncbugeye]

I am looking into buying a MityVac brake bleeder, and was wondering what the real minimum compressor needs are. My compressor is the "dilettante" model, a feeble little plugin Husky from Home depot (no guffaws of laughter from you pro shop dudes), is is rated at 2cfm @ 90psi, 3cfm @ 40psi, and the spec for the MityVac 6830 seems to require MUCH more than this. Why does the MityVac need so much?

 

[walshja]

Chris, I have a handheld MityVac brake bleeder and while it does work, I recently purchased the speed bleeders off eBay for my clutch slave cylinder, and I think they work great.

pretty cheap off eBay, and simple to use.

just throwing that out there . . .

 

[Jim_Gruber]

For reference purposes, here is a note I saved

Speed bleeder sizes:
Clutch (all spridgets) 3/8 x 24
Disc brakes 3/8 x 24 front drum brakes 3/8 x 24
Rear brakes (1 piston 1/4 leaf springs) 3/8 x 24
Rear brakes (2 piston wheel cylinder, semi eliptical leaf springs) 1/4 x 28
Found some at an Advance Auto, Dorman Help! brand, part #12701 (carried by others, like AutoZone I think) These fit my slave and should fit the front calipers. 2 for $10. I popped one in the slave, clear hose to bottle, pumped the pedal, watched a few air bubbles fly through, then nothing.

PS instead of a 7/16" wrench to turn, it's a 3/8". So I put one in my vise and bent it so I can turn through the access hole.

 

[PC]

... My compressor is the "dilettante" model, a feeble little plugin Husky from Home depot (no guffaws of laughter from you pro shop dudes), is is rated at 2cfm @ 90psi, 3cfm @ 40psi, and the spec for the MityVac 6830 seems to require MUCH more than this. Why does the MityVac need so much?

It looks like it generates vacuum by using the Venturi effect, which is basically blowing a lot of air through a small hole.

This sort of device is used heavily for industrial applications because of its simplicity and reliability. But they do require a lot of air while while pumping down and don’t flow very much volume through the vacuum port.

I haven’t tried a MityVac bleeder, but brake bleeding normally doesn’t need much vacuum flow. So hopefully you’ll only have to blow air in occasional short bursts to pump it down and the average load on your compressor won’t be too big.


pc.