Vestil LDLT series - Manual (Page 16)

16
OPERATING INSTRUCTIONS FOR
TWO- SPEED FOOT PUMP
FEATURES:
Your new lift equipment has been supplied with an exclusive
single-speed or two-speed foot pump. The internal features of
your pump includes a primary pressure relief, pressure
compensated return flow control valve, and an integrated
lowering valve. Replacements are necessary.
OPERATING INSTRUCTIONS:
Stay clear of moving parts. The platform will rise as the foot
pedal is pumped. Depressing the release lever will lower the
table at a controlled rate of descent. In the event the platform
has been overloaded, the pressure relief will open because of
excessive pressure buildup in the hydraulic system. Oil will
bypass into the reservoir. Never increase the pressure relief
setting more than necessary. Do not exceed the rated
capacity of your equipment.
TWO-SPEED SELECTION:
The two-speed hydraulic foot pump offers two "speeds". The
low speed products
low volume/high pressure. The high
speed products high volume/low pressure. The operator has
the option of selecting the optimum pump speed for the
application at hand. Pump speeds are selected by sliding the
"lock collar" (Item #2 on the parts identification) in or out. An
occasional drop of oil will keep the collar working freely.
AIR BLEED PROCEDURE FOR TWO-SPEED
FOOT PUMP
Whether your pump is a new installation, or has been recently
serviced, air has likely entered the hydraulic system. The
design of this pump includes an "air bleed screw" which will
aid in the removal of unwanted air from the foot pump area of
the hydraulic system. Use the following steps to remove this
air from the system.
1) Check all fittings to be sure they are tight. Ensure that the
oil is filled to within 1" of the top of the reservoir when the lift
is in the fully lowered position.
2) Locate the "air bleed screw" (item #34 on the pump body)
and loosen approximately 1/2 turn counterclockwise. As
soon as you have loosened the screw, slowly depress the
foot pedal. This unit will force the air out of the pump
chambers. Before you let the pump pedal return to the "up"
or "home" position, tighten the air bleed screw. This will
prevent air from reentering the pump chamber. Repeat the
above procedure until the pump chamber is completely filled
with oil and a "spongy" feel is no longer present. If the air
bleeding procedure has been successful, the feel of the pump
pedal will be firm and the complete stroke of the pump will
produce fluid flow.
Air can also become trapped in the hydraulic cylinder(s).
Review your owners manual for air removal instructions.
HYDRAULIC DIAGRAM FOR TWO-SPEED FOOT PUMP
2 SPEED
FOOT PUMP
PRESSURE
CHECK VALVE
ADJ. PRESSURE
RELIEF VALVE
PRESSURE
CHECK VALVE
PRESSURE COMPENSATED
FLOW CONTROL
1GPM
TO CYLINDER
LOWERING
VALVE