c.
Turn on the motor and stall the pumps at the
lowest pressure setting (compensator knob
turned fully counter-clockwise). The pump
will travel in either the A or B direction until
the pressure setting is reached.
d.
Identify the solenoid that is operating by
viewing the direction indicator lights on the
cover of the directional valve (207). Measure
voltage across the associated terminals to
determine if proper voltage is reaching the
valve (approximately 200 to 240 VAC). See
Electrical Schematics, page 94
, and the table
below, to identify the proper terminals to
measure across.
e.
Trigger each proximity switch (211) with
the shaft of a screwdriver, confirming each
solenoid within the directional valve (207)
operates as described in table below.
f.
If one or both sides are not operating
properly, according to the table, first
reconfirm wiring to directional valve (207) per
Electrical Schematics, page 94
, then replace
directional valve (207).
For
For
For given
given
given
pump
pump
pump
movement
movement
movement
direction:
direction:
direction:
Pump
Pump
Pump driving
driving
driving
left
left
left (toward
(toward
(toward
park
park
park position)
position)
position)
Pump
Pump
Pump driving
driving
driving
right
right
right (away
(away
(away
from
from
from park
park
park
position)
position)
position)
ADM indicates
Indicator light
on directional
valve cover
Left arrow,
labeled “b”
Right arrow,
labeled “a”
Last proximity
switch
triggered
Right side
proximity
switch
Left side
proximity
switch
Terminals in
directional
valve
energized
Terminals
associated
with red and
orange wires
Terminals
associated
with black and
white wires
Note
For diagnostic purposes, it is possible to
manually override the directional valve by
using a small screwdriver to depress the
button in the center of either directional
valve end cap. Depressing the button in
the right end cap should cause the pump
to travel to the right. Depressing the left
button should cause the pump to travel
to the left.
5.
If you have determined that the cause is none
of the previous possible causes, check for a
loose piston packing retaining bolt. This causes
the piston to contact the inner face of the pump
inlet flange before the switching plate activates
the proximity switch. Shut down the unit and
disassemble the appropriate pump for repair.
Following
Following
Following step
step
step 1,
1,
1, ifif
if the
the
the proximity
proximity
proximity switch
switch
switch indicating
indicating
indicating
lights
lights
lights do
do
do not
not
not light:
light:
light:
6.
Check for loose or faulty proximity switch cable
or connections. Confirm the connections to the
proximity switches are tight and internally free
from oil and other contaminates.
7.
Swap the cables to the proximity switches to see
if the problem follows the switch or is in the cable.
Replace either the failed switch or the cable.
8.
Replace the HCM. See
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334946C