Bleeding using a vacuum can

[chrismoore701]

I picked up a cheap vacuum gun with a cup. Can I plug it onto my bleeder. Pump it up and crack the bleeder? Is this a good way to get the air bubbles out? I searched the site and came up empty. I bleed the system and now I am about 1 inch off the floor. 3 pumps and I am good. But a little low for my comfort. Brand new system on my frame off. 1979

[Chknlyps2]

Originally Posted by chrismoore701

I picked up a cheap vacuum gun with a cup. Can I plug it onto my bleeder. Pump it up and crack the bleeder? Is this a good way to get the air bubbles out? I searched the site and came up empty. I bleed the system and now I am about 1 inch off the floor. 3 pumps and I am good. But a little low for my comfort. Brand new system on my frame off. 1979

I crack the bleeder and then start pumping. There should be a short little hose in the cup that goes into the fluid you suck out and keeps air from getting back into the system from the cup. I have had one for many many years, works like a champ. The long hose on mine is getting stiff and it will pull the little rubber ends that fit over the bleeder nipple to the side and you can hear it suck air a little some times. I just have to hold the rubber piece square on the nipple while I pump.

[chrismoore701]

I have heard of people pressurizing the master cylinder. Figured this is pretty much the same thing

[Chknlyps2]

Originally Posted by chrismoore701

I have heard of people pressurizing the master cylinder. Figured this is pretty much the same thing

Probably. I like the cup because there is no mess and you can see when the bubbles disappear. You can use the cup even if you have a person in the cab pumping the pedal, check the reservoir often because it is easy to suck it dry.

[hatzie]

Originally Posted by Chknlyps2

Probably. I like the cup because there is no mess and you can see when the bubbles disappear. You can use the cup even if you have a person in the cab pumping the pedal,

check the reservoir often because it is easy to suck it dry.

That's one reason why pressure bleeders are so nice. The pot has at least 1-2 quarts of fluid so you'll be hard pressed to run the MC dry. I've run into systems on Squarebody, T400, & T800 GM trucks, C3-C5 Corvettes, and several other makes that would not completely bleed using Gravity, Vacuum, or pumping the pedal. They all bled air out completely using my pressure bleeder. The pedals were solid and tight when I finished bleeding this way.

You can build a pressure bleeder using a weed sprayer, master cylinder gasket, and a chunk of plastic cutting board with all-thread and wing nuts or dog chain, J-bolts, and wing nuts to hold it on the MC.

When I made mine the Motive Products units were too rich for my blood. The Motive Products #105 GM unit is just under $70 on Amazon now. A weed sprayer is $15-$20 and air pressure gauges are $5-$15 at the hardware store. The other misc parts could add up to near what the Motive unit costs now... not to mention your time. Do your homework before you commit to building one rather than slapping down some cash.

I use empty 2Litre pop bottles as catch cans. Make the clear bleeder hose long enough to just set em on the floor.

My read on this is... You can get it done now or waste a bunch of time screwing around with stuff that might work. Pressure bleeding works.

[KQQL IT]

Unless the proportioning valve kicked over, couldn't get mine to center had to take it apart and push it back.
The joys of 40+ year old junk.

[hatzie]

Originally Posted by KQQL IT

Unless the proportioning valve kicked over, couldn't get mine to center had to take it apart and push it back.
The joys of 40+ year old junk.

They won't bleed at all with a tripped combination valve. No matter what method you choose.

[chrismoore701]

No tripped valve. All brand new system. But my peddle is about 1" off the floor. A little close for my comfort. 3 pumps and I am up. I may have a leak. That will also be looked into

Thanks

[SkinnyG]

A low pedal may also be improperly adjusted drum brakes - check those first since it's an easy fix. You want slight drag against the drum.

I like to bleed with this, and 25' of vacuum line.



Hook the vacuum line to one spigot, and the other end to manifold vacuum, and the engine sucks the fluid out for me. Very quick.

[Chknlyps2]

Originally Posted by SkinnyG

A low pedal may also be improperly adjusted drum brakes - check those first since it's an easy fix. You want slight drag against the drum.

I like to bleed with this, and 25' of vacuum line.



Hook the vacuum line to one spigot, and the other end to manifold vacuum, and the engine sucks the fluid out for me. Very quick.

That is the exact same cup and fittings I have but they are 20 + years old. Never thought about using manifold vacuum, that is pretty cool!

[chrismoore701]

I put the unit on the rear brakes. Got a little fluid out but not much. Adjusted them a little. Could not get the unit to fit on the front bleeders. Will see how it runs now. If I need to do it again I think I will dig up a pressure system with a weed sprayer and see how that works

[chrismoore701]

Brakes work 10 times better now. I would say that are perfect but don't want to jinx it