Motive power bleeder

[DWBOX2000]

How would one pump new fluid into system if the jug wasn’t filled? I need to find a new top with pump.

[peppy]

Originally Posted by DWBOX2000

How would one pump new fluid into system if the jug wasn’t filled? I need to find a new top with pump.

I take the motive bleeder off and refill the master cylinder. I find it easier than cleaning the motive bleeder.

[berettafan]

I have a dumb question on this for those who put fluid in the jug- where does the air in the line from jug to cap go and how does it not get introduced into the brake lines?

And now I'm wondering how do you release the pressure in the jug when done bleeding? I guess you just unscrew the cap on the jug? I did run across some generic bleeders on amazon that had a release valve on the canister. Seems like that is a better design?

[DWBOX2000]

Not sure what happens to the air but I’m assuming it gets pushed through. I believe the idea is to fill the container a bit and master cylinder reservoir to the top. Pump to 20 psi and then crack the bleeders on the calipers one at a time. The pressure pushes the pressurized fluid in container through the system. I would think to keep opening the reservoir after each caliper would be time consuming and messy. I could be wrong but that’s how I saw it done. No pumping of the brakes necessary unless you are starting with a lot of air already in the system.
Fact check required.

[KFC911]

20 is too much... methinks 14.
I will be corrected if wrong

edited... I may add fluid to the res. once or twice during the process... no biggie.

My Carrera (930 brakes & larger m/c) has a clutch to bleed too... no pumping brakes on that.

Dry & clean .... no muss ... no fuss.

[greglepore]

Originally Posted by berettafan

I have a dumb question on this for those who put fluid in the jug- where does the air in the line from jug to cap go and how does it not get introduced into the brake lines?

And now I'm wondering how do you release the pressure in the jug when done bleeding? I guess you just unscrew the cap on the jug? I did run across some generic bleeders on amazon that had a release valve on the canister. Seems like that is a better design?

Yes, there is air in the line but it doesn't get pulled into the master, I'm guessing for the same reason that atmospheric air doesn't get past the reservoir and into the master.

To release pressure you unscrew the top of the tank.

It works without fluid in the tank, and if just bleeding that's fine-if flushing, you can run the master dry if not careful and then you have to start over. The fluid never makes it into the pump, so it doesn't hurt the pump.

[911 Rod]

To get a nice firm pedal for track duty I used the bleeder and have someone pumping on the brake.

[DWBOX2000]

Road and track says fill power bleeder with a brake fluid , pressurize to about 15 psi and then crack bleeder screw.

[berettafan]

i think that psi changes by system. iirc my gti needs 30.

[aschen]

[QUOTE=DWBOX2000;12362290 I would think to keep opening the reservoir after each caliper would be time consuming and messy. No pumping of the brakes necessary unless you are starting with a lot of air already in the system.
Fact check required.[/QUOTE]

Not messy at all and no bottle to clean. The process is the same put pressure on the master cylinder with air on top or the MC reservoir. Crack the bleeders and bleed out as much fluid as you want/need.

Only difference is you watch the MC fluid level to make sure it doesnt get to low. In my experience you have to fill it 2x to completely flush a system. Would depend on reservoir size brake line lengths etc.

It is functionally identical procedure to applying pressurized fluid to the MC and results in a rock hard brake pedal in my experience. Filling the bottle seems like a good idea if you work in a pro shop and you do a couple brake jobs a day or you want to flush a ton of brake fluid.


I heard in yea olden days people would fabricate a similar bleeding system by hooking a tire to a long hose and adapting to a spare MC cap.