User Manual
03/10/03 9/7/2017 HDD, MANUAL
Copyright 2017 Vestil Manufacturing Co. 13 of 25
Cleaning lowering solenoid valve: If the chute slowly loses elevation without pressing the DOWN button, lower the
chute completely. Then, remove, inspect, and clean the lowering cartridge valve in the following manner:
1. Lower the chute completely and turn off electrical power to the unit. If your dumper is AC powered,
unplug the electrical cord from the wall socket. If your unit is DC (battery) powered, turn the power
switch to the OFF position.
2. Unload the dumper.
3. Remove the nut that fastens the solenoid coil to the valve stem; then remove the coil and unscrew the
valve from the manifold.
4. Inspect the valve for blockage.
5. Inspect O-rings and back-up washers for cuts, tears, etc.
6. Submerge the valve in mineral spirits or kerosene.
7. Use a thin tool, such as a small screwdriver or a hex wrench, to push the poppet in and out several
times from the bottom end of the valve. The valve should move freely, about 1/16” between the closed
and open positions. If the poppet sticks, the valve stem might be bent. Replace the poppet if it doesn’t
free up after cleaning.
8. Remove mineral oil from the valve with compressed air.
9. Move the poppet in and out.
10. Inspect the bottom of the valve cavity in the manifold for foreign matter.
11. With the thin tool, press the middle of the flow control spool, which is located in the bottom of the
cavity. It should move down and up smoothly.
12. Reinstall the valve in the manifold and tighten it to 20 lb·ft of torque.
Bleeding air from hydraulic system: If the chute lowers extremely slowly or does not lower, air in the cylinders
might be the culprit. Air in the hydraulic system causes the velocity fuse to close, which traps oil in the cylinder. To
overcome this problem, air must be “bled” from the system.
Completely lower the chute and unload it;
Locate the bleeder valve located at the top of the cylinder (it looks like a grease zerk). Hold a rag over the valve
and open it about a half turn with a 1/4” or 5/16” wrench. Oil and air will sputter from the valve. Jog the motor by
pressing the white (UP) button for just a second. If air continues to escape from the bleeder valve, jog the motor
several more times. Wait at least 5 seconds between successive jogs.
Close the valve once air no longer is heard or seen bubbling out of the valve. At this point, just a clear stream of
oil is seen flowing from the bleeder valve. Close the valve.
Remove the cover from the modular power unit and check the oil level in the reservoir. If the surface of the oil is
lower than 1 to 1½ in. below the fill hole, then add oil until it is between 1 and 1½ inches of the fill hole. Add only
anti-wear hydraulic fluid with a viscosity grade of 150 SUS at 100°F (ISO 32 @ 40°C) like AW-32 or Dexron
transmission fluid.
Item
Part no. Description Quantity
1
01-127-010
Manifold, aluminum, w/o valves
1
2
01-135-052
2HP, 3-phase, 1725 RPM motor
1
3
01-143-908
Gear pump, 0.153 displacement
1
4
99-021-909
Cylinder, 2
1
/
2
” x 18” ram style
2
5
99-153-006
Relief valve, 210 bar, size 08
1
6
99-031-029
Inlet screen, 100 mesh 2” pancake
1
7
99-153-038
Flow control, PC,
7
/
16
” - 20, 2gpm
1
8
01-531-001
Velocity fuse, adjustable, brass
2
9
99-153-015
Valve, cartridge, NC, no coil, w/ nut
1
10
99-153-011
Check valve, size 08
1
11 99-023-002
Reservoir, L-shaped, 1.16 gal., 1.0
gal. nominal
1
FIG. 9: Hydraulic circuit diagram