a. Position the foot control so that the silver top is face down.
b. Remove the four Phillips screws from the base. This will release the silver
top.
c. On the bottom of the foot control, remove the two Allen screws that are in the
center of the black base.
d. Separate the top of the foot control from the base.
e. Remove the stem with the retaining ring by sliding the stem up.
f. Turn the assembly over.
g. Remove the visible O-ring and slide the spacer out.
h. Remove the three O-rings and two spacers from inside the valve.
i. Grease the new O-rings lightly with A-DEC Silicone Lubricant prior to inserting
them into the grooves.
j. Reverse steps a. through h. to reassemble the valve.
NOTE:
Before installing O-rings, always apply a light coating of silicone grease. This
makes installation easier and will prevent the O-rings from being damaged.
The seal bores should also be lightly lubricated before inserting the stems or
6-5.
REMOVE AND REPLACE MASTER BLOCK 3-WAY CARTRIDGE VALVE
STEM O-RING
After troubleshooting an air leak on the master block to a cartridge toggle valve
that is turned ON, you isolate the problem to a defective O-ring on the stem. You must
remove and replace the defective O-ring. Refer to figure 6-14, number 6A.
a. Pull the knobs off of the air and water coolant flow controls. The cartridge
valves are flanged so that they cannot be removed through the faceplate.
b. Remove the two screws that secure the master block to the faceplate, then
move the block assembly away from the faceplate.
c. Turn the air to the unit off at the floor utility box and bleed all air pressure left
in the system.
MD0371
6-9