Vestil HDC-450 - Manual (Page 7)

7
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 valve
b. Particle of dirt under inlet check valve
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 clevis or
pivot points 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
compensated 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.) Cradle does not raise
2.) Foot pedal goes down hard but
cradle does not raise
3.) Unit will pump under no load or
when rapidly stroked, or pedal will
stroke without pumping
4.) Cradle raises when the pump is
stroked but lowers on return stroke
5.) Cradle raises but takes too much
effort
6.) Cradle raises but is too slow
7.) Spongy or jerky operation
8.) Cradle lowers too slow
9.) Cradle lowers too fast
10.) Cradle 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 cradle - Disassemble, clean and re
assemble pressure relief valve*
b. Lower cradle - Disassemble, clean and re
assemble 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 cradle - drain reservoir, clean and
flush debris, refill with clean oil
c. Lower cradle - Disassemble, clean and re
assemble pressure relief valve*
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 cradle - Disassemble, clean and re
assemble
d. Lower cradle - Disassemble, clean and re
assemble pressure relief valve*
a. Lower cradle - Disassemble, clean and re
assemble pressure relief valve*
a. Lower cradle - Disassemble, clean and re
assemble pressure relief valve*
b. Replace as necessary
c. Correct as necessary
d. Remove air from hydraulic system, to un
lock, repressurize system
*Refer to exploded view
Trouble shooting Guide for Single and Two-speed Hydraulic Foot Pump