REMOVE AND REPLACE FOOT CONTROL SIGNAL RELAY VALVE O-RINGS
After troubleshooting for an audible leakage when you are not using the foot
control, you isolate the fault to defective O-rings in the foot control signal relay valve.
To correct the fault, you must remove and replace the O-rings. Refer to figure 6-13.
Figure 6-13. Foot control.
Before removing the foot control cover, turn the air supply off and bleed
all of the pressure from the system. If this is not done, the stem
assembly may be ejected from the foot control valve. Never turn the air
supply to the foot control on when the cover is off of the foot control,
unless appropriate steps have been taken to ensure that the stem
assembly cannot be ejected.