Manitowoc 2250 Service And Maintenance Manual

Reference Only
INTRODUCTION 2250 SERVICE/MAINTENANCE MANUAL
1-82
Published 11-06-15, Control # 040-13
Tongue Cylinder
See Figure 1-50 and Figure 1-51 for the following procedure.
Tongue cylinder aligns the wheeled counterweight trailer for
attachment to crane and levels the counterweight tray before
positioning steering wheels. Wheeled counterweight tray
pins must be in proper position for leveling. See MAX-ER
Assembly/Disassembly topic in Section 4 of Operator
Manual for pin positions. After wheeled counterweight trailer
is leveled, return tray pins to operating position.
Power is available to MAX-ER remote switch assembly when
power cable (W28) is plugged into receptacle at left side of
counterweight trailer and engine is running. When power
button on MAX-ER remote switch assembly is pressed,
power is enabled to operate tongue cylinder switch. The
switch is spring-returned to OFF position. In off position, the
tongue cylinder solenoid valve is “motor spooled” with both
cylinder ports and tank port connected when not enabled.
This prevents premature opening of counterbalance valves
at the cylinder.
Tongue Cylinder Extend
When power button is pressed and tongue cylinder switch is
enabled and held in the extend UP position, an input signal is
sent to the PC. A 12-volt output signal from PC enables the
tongue cylinder extend solenoid HS-50. Internal pilot supply
pressure of 200 psi (14 bar) enables selected spool to shift
the tongue cylinder solenoid valve. The crane PC sends an
output signal to shift crane auxiliary system disable valve
HS-12, to block valve bypass. Accessory system pressure
increases to operate accessory items. Accessory system
fluid enters MAX-ER accessory valve and flows to free-flow
check valve section of counterbalance valve, entering piston
end of the tongue cylinder and starts to extend the tongue
cylinder. Fluid from rod end of cylinder is blocked by free-flow
check valve section of counterbalance valve and flows
through the flow restraining section that has a relief setting of
2,800 psi (193 bar). Return hydraulic fluid then exits
counterbalance valve and passes through MAX-ER
accessory valve before returning to crane hydraulic tank
through return line. Release tongue cylinder switch to OFF to
lock tongue cylinder in position.
56MB
56MA
89H4
55MB
55MA
POWER
HS
51
HS
52
HS
53
HS
41
HS
40
89J4
89K4
0
15 AMP
CB
5A
8K
RM-05
AUXILIARY SYSTEM
DISABLE VALVE
TONGUE CYLLINDER EXTEND
CRANE
PROGRAMMABLE
CONTROLLER
TONGUE CYLLINDER RETRACT
STEERING PINS EXTEND
STEERING PINS RETRACT
COUNTERWEIGHT STRAP
CYLINDER RETRACT
COUNTERWEIGHT STRAP
CYLINDER EXTEND
MAX-ER 2000
PROGRAMMABLE
CONTROLLER
MAX-ER 2000 REMOTE
12
HS
HS
50
FIGURE 1-50
88S

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English