35PI-121January 2020
Problem Remedy
Constant Pressure
Mode or Dump
Mode: Water leaks
from dump port
when gun triggers
are squeezed.
1. If the air pressure gauge on Multi-Mode Valve
reads below 80 psi when gun is rotating, increase
air pressure by turning regulator knob on Multi-
Mode Valve clockwise, or increase the pressure
from the air supply source.
2. Remove and check cartridge from Multi-Mode
Valve for seal wear and debris or wear on metal-
to-metal sealing surfaces of cartridge valve and
seats. Replace if necessary.
Water flows
through gun
nozzles when
triggers are not
squeezed.
1. Remove and check cartridge from Multi-Mode
Valve for seal wear and debris or wear on metal-
to-metal sealing surfaces of cartridge valve and
seats. Replace if necessary.
2. Remove the four capscrews that connect the air
cylinder to the mounting plate on top of the valve
body, but do not remove the capscrews that hold
the air cylinder together, and do not disconnect the
air line that connects the cylinder to the brass pilot
valve.
Check for evidence of rubbing by the piston of the
air cylinder against the bore inside the plate that is
mounted above the Multi-Mode Valve body. If any
is visible, center the cylinder over the plate, reat-
tach, and re-check system operation.
If the piston on the underside of the cylinder does
not extend outward and retract quickly when the gun
triggers are squeezed and released, or if the piston
doesn’t extend fully to 3/8” (10 mm), replace air
cylinder.
Do not operate a control gun if water
through the gun does not shut off completely when trig-
gers are released. If this problem is encountered, shut
down system immediately and correct malfunction before
continuing. Operating a gun without the ability by the
operator to shut off high pressure water to the gun “at
will” could result in serious injury.
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