Bench bleeding removes the air from the master cylinder
prior to the installation. Bench bleeding reduces the amount of bleeding needed
after the installation onto the vehicle.
- Plug the outlet ports.
- Mount the master cylinder in a vise with the front end tightly
tilted slightly down.
- Fill the reservoir with clean brake fluid.
- Stroke the primary piston about 25 mm (1 in) several
times using a smooth, rounded end tool. Resistance to the primary piston travel
will not allow the full 25 mm (1 in) stroke when air is bled
from the master cylinder.
- Reposition the master cylinder in the vise with the front end
tilted slightly up.
- Repeat the stroke to the primary piston of about 25 mm
(1 in) several times.
- Reposition the master cylinder in a vise to the level position.
- Loosen the plug(s) one at a time.
- Push the piston into the bore in order to force the air from the
cylinder.
- Tighten the plug(s) before the piston returns to the original
position in order to prevent air from being sucked into the cylinder.
- Fill the reservoir. Refer to
Master Cylinder Reservoir Filling
.
- Perform the normal bleeding procedure after the master cylinder
is installed. Refer to
Hydraulic Brake System Bleeding
.