Power bleeder operation

[michigan]

I just recently changed the brake fluid in my 1977S. I bought the power bleeder to do the job because I can never find someone to help push the brake pedal down for me when I need it. In any event, I pumped it up to about 15 pounds pressure and prodeded to go around to the right rear and get started in the bleeding process. I notice fluid in the front of the car. Its the new brake fluid that I just put in the reservoir coming out the air tube. I loose the fluid. I try again with less pressure. Same thing. I was'nt loosing any fluid before the project, haven't lost any since finishing the project the old fashion way. What did I do wrong? Pedal now strong, stops on a dime.

[fred cook]

Don't feel too bad! I did the same thing the first time I used my power bleeder. If you take a look at the fluid resevoir on the master cylinder, you will find an overflow vent on the left (drivers) side of the resevoir. Pull the hose, make a plug using a short piece of vacuum line with a small screw in the end, put the newly made plug on the resevoir and you will be good to go.

Good Luck!

Fred Cook
'80 911SC

[Lothar]

Many of us just use a pair of needle nose vise grips and pinch the overflow hose to eliminate the problem. Does this risk damage to the hose. I notice that it has a braided cover but what material is used under the cover?

[APKhaos]

All you need to do is lightly crimp the overflow hose.
I bend to hose over itself, and hold it bent between the jaws of a cresent wrench - just enough to keep it crimped, which is not very tight.

[jlex]

Next time, hook up the unit without putting the fluid in... pump the pressure up & make sure it holds the indicated pressure for a couple of minutes to show it won't leak fluid later. If the guage shows no pressure drop, then you won't have any leaks later when you add fluid & do the job. It took me a few tries with the "dry run" before I had the overflow tube sealed to my satisfaction.
regards,
jlex.

[michigan]

Thanks guys. A simple problem with good answers. I should have realized that that would solve my problem. Got lost in the forest because of the trees.