BENCH BLEEDNG THE MASTER CYLINDER
Whenever a master cylinder has been removed
from a vehicle or a new one is being installed,
the master cylinder must be bench bled . Failure
to bench bleed is the main reason for unsuccess-
ful master cylinder replacement . Bench bleeding
greatly decreases the chance that any air will
be caught in the cylinder upon rein stallation .
Follow this procedure:
1) Plug outlet holes of the master cylinder and
gently clamp it in a vise with the push rod end
slightly elevated . NOTE: Damage may result if
master cylinder is clamped by the bore or if
reservoirs are clamped too tightly .
2) Fill the master cylinder with an approved type
brake fluid and keep it filled at all times during
the procedures .
3) Remove a plug from the master cylinder and
attach the proper adapter to this mas ter cylinder
outlet port . Connect the pump tube to the reservoir
jar and the jar tube to the adapter (FIGURE 19) .
4) Operate the pump and observe air and fluid
flowing into the reservoir until clear, bubble-free
fluid appears .
5) Plug the outlet tightly and repeat step 4 on the
other outlet ports .
6) Clamp master cylinder in a vise with the push rod
end down slightly . Slowly slide the master cylinder
push rod back and forth about
1
⁄
8
”, until no air
bubbles can be seen in the reservoirs .
7) Remount the master cylinder with the push rod
end up and follow steps 3 & 4 on all outlet ports .
Plug ports tightly . The master cylinder is now free
of air and ready to install .
braKe bLeeDinG
FIGURE 19: BENCH BLEEDING
Page Number - 24
Form 824426
