29.
f. With the liftgate at the ground, disconnect the power unit and remove the
reservoir. Check to see if the suction tube is clogged or has fallen out of
the pump base. Clean the screen or reattach the suction tube as required.
g. If all else fails replace the power unit, it is probably worn out.
3. Problem – Liftgate will not lower
Causes - a. Defective lowering solenoid coil or valve
b. Clogged or defective hydraulic lines, fittings or flow controls
Corrections - a. With the “LOWER” switch engaged check for voltage on the green wire at
the switch. If no voltage is present replace the switch. If voltage is
present, with the “LOWER” switch engaged, check for voltage at the
green wire on the lower solenoid valve coil terminal. If no voltage is
present, the green wire from the “LOWER” switch is loose or broken and
needs replaced. If there is voltage (minimum of 9.5 volts) and the valve is
not opening to allow the gate to lower, either the lower coil is bad or the
entire lower coil/valve assembly is bad. To check to see if the coil is
defective, remove the green wire from the spade terminal on the lower
coil and check for continuity between the spade terminal and the nut,
which holds the coil on the valve stem. If continuity does not exist, replace
the defective coil, otherwise replace the defective lower coil/valve
assembly.
b. Remove any obstruction in the hoses, fittings or flow controls or replace
any hose, fitting or flow control, which does not allow fluid to flow through
freely.
4. Problem – Liftgate raises slowly – The raise speed of the M25/30 on a 54” bed height while
empty at 70°F is approximately 7-12 seconds. The raise speed loaded for the
same conditions is approximately 15-25 seconds. These speeds vary with each
model.
Causes - a. Overload condition
b. Cold weather
c. Partially blocked suction screen
d. Lift cylinder is bypassing
e. Improperly adjusted or defective raise relief valve
f. Low voltage and/or bad ground
g. Worn out pump
Corrections – a. See section 2b
b. Refer to Owner’s Manual for alternative oils to use for cold weather
conditions.
c. Remove reservoir and clean or replace suctionscreen as necessary.
d. See section 2d
e. See section 2c
f. The minimum voltage between the motor stud and ground is 9.5 volts at
maximum load conditions. See section 1b and 1c.
g. After all other corrections are performed it will be necessary to replace the
pump.
