258
Hydraulic System
Dual Vane Pump
E
XPERT
™ vehicles with automatic loading arm are equipped with a dual vane pump. Both sections of
the dual vane pump are activated by two electric solenoid valves. One is mounted on the pump and
the other on the chassis (see Figure 5
3). The electrical signal that activates the solenoid is sent by the
pump switch on the control panel.
Figure 5
-
3 Vane pump solenoid valve on the pump (1) and on the chassis (2)
When the truck is started, various multiplex modules start monitoring the vehicle and the engine
speed, and allow the vane pump to engage (or not). If the vehicle is going faster than 15 mph (25 km/
h) or if the engine speed exceeds 900 RPM, the vane pump will not engage.
The first section of the vane pump, known as the
body
vane pump, located closer to the pump shaft,
powers all body functions (tailgate, body hoist, and packer) through the directional control valve (see
on page 258). It is capable of delivering a flow of 20 GPM at 700 RPM. A
dump valve located on the chassis (see Figure 5
2) limits the flow to the valve to 45 GPM. All excess
flow is sent back to the hydraulic tank. When the pump is turned off, the oil returns to the hydraulic
tank.
The second section of the vane pump, known as the
arm
vane pump, powers lifting arm functions and
other options through the proportional valve (see
on page 260). It is capable of
delivering a flow of 16 GPM at 700 RPM. A dump valve located at the pump outlet limits the flow
3) to the valve to 20 GPM. All excess flow is sent back directly to the pump inlet. When
the pump is turned off, all the oil returns to the inlet.
Directional Control Valve
E
XPERT
™ vehicles are equipped with a directional control valve (see Figure 5
4), as part of the
body
vane pump, that powers all body functions (tailgate, body hoist, and packer).
1
2
Summary of Contents for EXPERT
Page 1: ...EXPERT TM MAINTENANCE MANUAL...
Page 2: ......
Page 3: ...EXPERT MAINTENANCE MANUAL...
Page 10: ...viii Table of Contents...
Page 18: ...8 Introduction...
Page 244: ...234 General Maintenance...
Page 251: ...Lubrication 241 Figure 4 11 Glass compartment lubrication chart optional...
Page 252: ...242 Lubrication Figure 4 12 EXPERT lubrication chart...
Page 264: ...254 Lubrication...
Page 320: ...310 Hydraulic System...
Page 357: ...Troubleshooting 349...
Page 358: ...350 Troubleshooting...
Page 386: ...378 Multiplexing...