Manitowoc 2250 Service Maintenance Manual

Reference Only
Manitowoc Published 07-19-16, Control # 249-01 10-55
2250 SERVICE/MAINTENANCE MANUAL TROUBLESHOOTING
10
Test 21—Adjusting the Counterbalance Valves
Each jacking cylinder (7) has a single counterbalance valve
at the piston end of the cylinder. The retract adjusting screw
at the valve provides adjustment for each jacking cylinder
load support. The extend adjusting screw allows cylinders to
be adjusted for uniform operation on level ground.
Counterbalance valves are pre-adjusted at the factory but
are not calibrated. Adjust counterbalance valves with a
closed-end wrench and hex wrench. To avoid over-adjusting
the cylinders, use a hex wrench as a guide and never turn a
counterbalance valve more than 1/2 turn in either direction.
To adjust a counterbalance valve, perform the following
procedure.
1. Loosen the adjusting lock nut.
2. Rotate the counterbalance adjusting screw 1/2 turn
clockwise (in) to lower the holding pressure.
3. Rotate the counterbalance adjusting screw 1/2 turn
counterclockwise (out) to raise the holding pressure.
4. While holding the counterbalance adjusting screw with a
hex wrench, tighten the lock nut.
5. Recheck the cylinder(s) for correct load support and
uniform operation.
Right side cylinder shown, for left side
item 2 is inboard and item 3 is outboard
P893
P1527
P901
P904
P905
Example
1
2
3
4
5
6
7
8
9
FIGURE 10-24
Item Description Item Description
1 Gantry Cylinder (right side) 6 Boom Butt-Handling Counterbalance (rod end)
2 Gantry Lifting Counterbalance (rod end—outboard) 7 Jacking Cylinder
3 Gantry Lifting Counterbalance (piston end—inboard) 8 Jacking Cylinder Extend Adjusting Screw
4 Boom Butt-Handling Cylinder 9 Jacking Cylinder Retract Adjusting Screw
5 Boom Butt-Handling Counterbalance (piston end)
CAUTION
Possible Component Damage!
The gantry cylinders will not extend evenly without
counterweights attached to the crane.
Follow the special instructions/warnings that apply when
adjusting gantry cylinders and boom butt cylinder
counterbalance valves as specified in Hydraulic and Air
Systems Section 2. Perform gantry cylinder adjustments
with counterweights installed.

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English