Manitowoc MLC165-1 Service Maintenance Manual

Reference Only
Manitowoc Published 05-26-17, Control # 238-02 8-1
MLC165-1 SERVICE/MAINTENANCE MANUAL UNDER CARRIAGE
8
8
SECTION 8
UNDER CARRIAGE
TRAVEL OVERVIEW
See Figure 8-1 and Figure 8-2
Travel Enable
The travel pilot controls whether or not pilot pressure is
ported to the travel control handle. This acts as a function
enable for the travel handle. Two conditions must be met for
node 4 to drive the travel pilot valve:
• Seat safety switch must be closed
• Travel parking switch is in the off position
When these conditions are met, node 4 sends a 24Vdc
signal to the travel pilot valve relay. The travel pilot valve
moves the open position, porting fluid to the P connection of
the control handle.
No Travel
When the control handle is in the neutral position, no fluid is
ported to the control valve pilots (a4 and b4). The valve
remains in the center position, blocking flow from the pump
to the crawler motor. The crawler brake also receives no
pressure and remains engaged.
Forward Travel
Travel handle movement to the forward direction ports fluid
to the control valve pilot a4 line. The valve moves to the open
position and ports fluid from A4 to the P1 connection of the
crawler motor. At the crawler motor valve, flow from the P1
connection creates a pilot flow that moves the valve to the
open position. Fluid is ported to the brake, releasing it, and to
the motor, rotating it. Fluid flows from the motor, back
through the open motor valve P1 connection, through the
open control valve B4 connection, and back to tank.
Reverse Travel
Travel handle movement to the reverse direction ports fluid
to the control valve pilot b4 line. The valve moves to the open
position and ports fluid from B4 to the P2 connection of the
crawler motor. At the crawler motor valve, flow from the P2
connection creates a pilot flow that moves the valve to the
open position. Fluid is ported to the brake, releasing it, and to
the motor, rotating it. Fluid flows from the motor, back
through the open motor valve P1 connection, through the
open control valve A4 connection, and back to tank.
Travel Speed Selection
Travel speed is selected by the travel speed selection switch
in the cab. Node 2 sends a 24Vdc output to the travel speed
selection switch. The switch is open in the low speed travel
position, so node 2 reads back a 0Vdc signal from the switch.
Node 4 sends a 0Vdc output to the travel speed valve
solenoid, de-energizing it. The valve remains closed, no fluid
flows to the servo pistons, and the swashplate remains in the
low speed position.
The switch closes in the high speed travel position, so node
2 reads back a 24Vdc signal from the switch. Node 4 sends a
24Vdc output to the travel speed valve solenoid, energizing
it. The valve moves to the open position, fluid flows to the
servo pistons, and the swashplate moves to the high speed
position.

Manitowoc MLC165-1 Specifications

General

Brand	Manitowoc
Model	MLC165-1
Category	Construction Equipment
Language	English