procedure that has never failed me (I have a '84 Porsche carrera which I run
at various road race tracks in the NE; am bleeding brakes ~10 times a year)
composes the following items:
1) Air tank (small one available at several auto parts stores for ~$30)
2) Rubber tire valve stem
3) Extra brake reservoir cap (I bought them at aftermarket suppliers for both
the Audi and Porsche; I assume you have a screw-on cap?
4) Clear plastic tubing that you can just barely squeeze onto the bleeder
5) Small clear plastic bottle, partially filled with fluid
1) Drill a hole in the center of the cap large enough to pull the tire valve
stem through from the bottom, and allow the rubber seat to seal against the
cap (some RTV sealant or epoxy helps here)
2) Remove the valve core from the body
3) Have the air tank pressurized to 25-35 lbs (NO MORE)
4) Screw the cap/valve onto the brake reservoir (make sure the reservoir is
5) Have the car jacked up, the wheel off on the caliper being bled, and fit
one end of the tubing on the bleed screw and insert the other end in the
plastic bottle until the tube end is down into the brake fluid. You can also
crack open the bleed screw, if you want.
6) Connect the pressure hose from the air tank to the cap/valve on the brake
7) Watch the tubing coming from the bleed screw, you should initially see
bubbles in the line and the fluid should be darker than clean fluid.
Continue until the fluid coming out is totally devoid of bubbles and the
same color as clear fluid (watch the end of the tube in the bottle). CHECK
THE RESERVOIR OFTEN; IT'S EASY TO TOTALLY VACATE THE RESERVOIR. If you have
to refill, disconnect the pressure hose and unscrew the cap and refill.
8) Once you're done on one wheel, close the bleed screw and then disconnect
the air tank. Go to the next wheel and repeat the process.
When you first connect the pressure hose, you might have leaks at any
reservoir connections (overflow hose, etc.) . They can be stopped with small
pieces of tubing with a bolt or screw in the end.
One other item I like to do is to pull out as much old fluid as I can out of
the reservoir first with a turkey baster, then fill with fresh fluid before
starting the bleeding. This reduces the amount of brake fluid I have to
I have used this procedure for several years without problems. I DON"t like
the two-person procedure where one pumps the pedal; my theory is that it runs
the master cylinder seals into areas where they normally don't run,and
promotes early wear. I went through two master cylinders in 3 years until I
changed to this procedure.
Also, if you hit the brakes once and they're spongy but feel fine after some
pumping, I would suspect the master cyliinder is going.