5
Possible Cause
Remedy
Observation
a.
Excessive load
b.
Oil is low
c.
Pinched hose
d.
Relief valve set too low
a.
Particle of dirt under the pressure relief
b.
Particle of dirt under inlet check
a.
Pump is air locked
b.
Inlet check valve has foreign material on seat
c.
Relief setting is out of adjustment
d.
Foreign material on relief valve seat
a.
Outlet check is leaking
a.
Change pump displacement speed
a.
Change pump displacement speed
b.
Intake filter clogged
c.
Foreign material stuck under pressure relief
valve or under inlet check valve
a.
Check for foreign material stuck in the deck
or frame rails
b.
Oil is low
a.
Pinched hose
b.
Intake filter clogged
c.
Foreign material lodged in velocity fuse
d.
Foreign material lodged in pressure
compensated flow control valve
a.
Foreign material lodged in pressure
compensted flow control valve
a.
Foreign material lodged in pressure
compensated flow control valve
b.
Release pin bent or missing
c.
Foreign object blocking roller travel
d.
Velocity fuse is locked
1.)
Deck does not raise
2.)
Foot pedal goes down hard but deck
does not raise
3.)
Unit will pump under no load or
when rapidly stroked, or pedal will
stroke with out pumping
4.)
Deck raises when the pump is stroked
but lowers on return stroke
5.)
Deck raises but takes too much
effort
6.)
Deck raises but is too slow
7.)
Spongy or jerky operation
8.)
Deck lowers too slowy
9.)
Deck lowers too fast
10.) Deck raises but does not lower
a.
Remove part of the load
b.
Fill oil to within one inch of the top of the
reservoir
c.
Correct as necessary
d.
Increase only as necessary
a.
Lower deck- Disassemble, clean and reas
semble pressure relief*
b.
Lower deck- Disassemble, clean and reas
semble inlet check valve*
a.
Bleed air from system inlet
b.
Remove and clean inlet ball and seat
c.
Adjust relief setting higher
d.
Lowering valve has foreign material on the
seat or is stuck in the open position
a.
Clean foreign material from ball and seat
a.
Slide locking collar back
a.
Slide locking collar forward
b.
Lower deck- drain reservoir, clean and
flush debris, refill with clean oil
c.
Lower deck- Disassemble, clean and reas
semble pressure relief*
a.
Correct as necessary
b.
Fill oil to within one inch of the top of the
reservoir
a.
Correct as necessary
b.
Correct as necessary
c.
Lower deck- Disassemble, clean and
reassemble*
d.
Lower deck- Disassemble, clean and reas
semble pressure relief*
a.
Lower deck- Disassemble, clean and reas
semble pressure relief*
a.
Lower deck- Disassemble, clean and reas
semble pressure relief*
b.
Replace as necessary
c.
Correct as necessary
d.
Remove air from hydraulic system, to un
lock, repressurize system (refer to hydraulic
schematic in manual)
Low Speed
High Speed
*Refer to exploded view
Trouble shooting Guide for Single and Two-speed Hydraulic Foot Pump
HYDRAULIC SCHEMATIC
Speed Selection for Two-Speed Hydraulic
Foot Pump
HYDRAULIC
CYLINDER
VELOCITY
FUSE
LOWERING
VALVE
INTAKE
SCREEN
2 SPEED
FOOT PUMP
