Vestil CART-1100-SS - Manual (Page 12)

FIG. 9: Hydraulic Control
Pedal Positions
P OSITION 1: H IGH SPEED FOR
R AISING D ECK ONLY (U NLOADED )
P OSITION 2: L OW
S PEED FOR L IFTING
To lower the deck, open the release valve by turning the release knob counterclockwise. The release knob is
item #250 in FIG. 1, and item #257 in FIG. 2 As you turn the knob, the lowering valve opens, which creates a
bypass around the check valve and the oil in the cylinder returns to the reservoir through the return hose.
If the deck continues to slowly lose elevation even though the release valve is closed, remove the lowering
(release) valve for inspection and cleaning.
Release Valve Removal & Cleaning Procedure:
1. Unload the cart.
2. Raise the deck and then install maintenance props in the roller channel (both sides) as indicated in FIG.
10 on page 13.
3. Unscrew and remove the valve (Item 241 in FIG. 1; Item 248 in FIG. 2) from the manifold
4. Use a small diameter magnet to remove the steel ball at the bottom of the valve cavity (Item 240 in FIG.
1; Item 247 in FIG. 2).
5. Inspect the valve stem and ball for contaminants.
6. Inspect the o-rings and back-up washers located on the valve stem for cuts, tears or other damage
7. Use mineral spirits (or kerosene) to clean contaminants from the valve stem, o-rings, back-up washers,
steel ball and valve cavity.
8. Inspect the ball seat at the bottom of the valve cavity. The ball seat should be a crisp, donut-shaped
shiny area with a hole in the center. If it is not, it may be necessary to “stake” the ball into place. This is
done by inserting the ball into the cavity and striking it using a ¼” grade-2 bolt and a small hammer. This
will create a new seat on which the ball will seal and prevent the oil from leaking.
There are 2 reasons why the deck might continue to slowly lose elevation even after cleaning and reinstalling
the release valve:
• Outlet check valve requires cleaning: Remove and clean the outlet check valve assembly (items
#229-232 in FIG. 1; items # 236-239 in FIG. 2). Follow steps 3 through 8 of the “Release Valve
Removal & Cleaning Procedure” above;
• Trapped air might be present in the cylinder.
Air Removal Procedure:
1. Unload the cart;
2. Raise the deck slightly (approx 5-6 inches);
3. Turn the release knob counterclockwise to lower the deck;
4. With the release knob held open, pump the pedal a few times;
5. Turn the release knob clockwise until it is snug;
6. Pump the pedal until the deck has elevated to approx 5-6 inches;
7. Again lower the deck while performing steps 4, 5 & 6.
Steps 1-7 should purge air from the system.
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