P : 8 5 5 . M P S . S H I P
m a c l e a n p o w e r . c o m
4 8 1 M U N N R D S U I T E 3 0 0
F O R T M I L L , S C 2 9 7 1 5
OTHER POWER UNITS
Any compatible open center hydraulic power supply that supplies 2-8 gpm and up to
2000 psi is acceptable for use with the LL-1. Be sure that the hydraulic flow direction
of the power unit matches the in and out labels on the control valve on the LL-1FPM
10 Ton Jack Assy. Reversed flow is a common problem and the jack will not extend
or retract when the control valve handle is shifted.
Caution: LL-1FPM jack assembly is a double acting jack designed to be operated with
hydraulic power sources capable of 2000 psi maximum and 2
– 8 gpm. If other power
sources are used, then the user does so at their own risk and it is highly recommended
that the user consult with a professional hydraulic supplier to determine the
combination is safe and that the bypass valve on the LL-1FPM is properly set.
TROUBLE SHOOTING
Symptom, Probable Cause & Remedy
Cannot connect hydraulic couplers:
Trapped pressure
– see paragraph 11
TRAPPED PRESSURE
Jack does not extend:
If the hydraulic flow not activated on power source, turn on
the flow.
Hydraulic flow direction backwards
: Check that the pressure port from hydraulic
power supply is mated to the port on the LL-
1FPM Valve labeled “IN”, and the return
(tank) port on the power source is mated to the port on the Valve labeled “OUT”.
See Drawing #50141 Sheet 1 of 2 for location of the port labels on the valve.
Jack does not achieve required load, but anchor is not moving:
Hydraulic flow
from power unit is too low. Open throttle on the power source to achieve a higher
flow rate. If this does not solve the problem, then readjust the bypass valve. This is a
common problem with alternate low flow rate power rate units.
Gauge reads 4000lb load with valve handle in neutral position, but there is no
load on anchor:
This is a characteristic of the hydraulic design of the control valve
called trapped back pressure. Back pressure from hydraulic flow is trapped on both
sides of the jack piston and registers on the gauge when the valve is shifted into the
neutral position. It does not affect the accuracy of the gauge reading if the
recommended method of proof testing is followed. The phenomenon manifests itself
to a greater degree at higher flow rates like 5- 8 gpm and is very evident when the
