Dover HEIL Command-SST - Page 172

Troubleshooting Pump on Command-SST™
No pump
function?
Is pump
switch on?
No
Turn on
pump
switch
Yes
Check for 12v
at PTO Coil. Is
correct
voltage
present?
No
Troubleshoot
electrical
Yes
Check standby pressure
with engine running
and pump switch on.
(Gauge port on valve)
Is pressure
between 400-500
PSI?
Yes
Standby pressure
greater than 400
PSI and still no
pump function?
No
Check PTO engagement pressure. (Trans
to PTO pilot line). PTO off at 170-220 psi
to engage pump. Pressure should be
220-298 PSI. Is pressure correct?
Check load sense pressure going
to pump compensator while
deadheading any function. Is
pressure 300 PSI or greater?
Yes
Check for
contamination in pump
compensator or
replace failed
compensator.
No
Check main control
valve for
contamination/obs
truction. Check for
failed valve coil.
Coil energized
when demanding
function?
See
troubleshooting
for main valve
Yes
No
Transmission
engagement
failure
Adjust compensator limiter to
2500 PSI and standby
pressure at pump
compensator to achieve 400-
500 PSI standby pressure. Is
pressure correct?
Yes
Put unit back
into service
No
Check high pressure
filer and hose for
obstruction. Was
obstruction found?
No
Remove pump and drain
line from oil tank. Hold in
bucket while
deadheading any
function. Note oil exiting
hose. More than 2 GPM?
Yes
Change
failed
pump.
No
Troubleshoot
PTO
Yes
Make repairs and
put unit back into
service.