Manitowoc Grove TMS800E User Manual

2-45
TMS800E SERVICE MANUAL HYDRAULIC SYSTEM
2
GROVE
Published 01-29-2014, Control # 496-00
HOLDING VALVES
Description
A bolt-on manifold style holding valve is installed on the
boom lift cylinder.
A cartridge style holding valve is used in each of the two
telescope cylinders. The holding valve installed on the outlet
of the cylinder provides meter out control, will lock the
cylinder in place, prevents a load from running ahead of the
oil supply, and relieves excess pressure caused by thermal
expansion.
Maintenance
Lower Lift Cylinder Holding Valve
Removal
1. Lower the boom to below horizontal.
2. Extend the boom to align the access holes in second
and third boom sections.
3. Install the telescope hold valve tool, P/N 80041761, see
Figure 2-30. While holding the tool in position have a
helper retract section 3 to lock the tool into place.
4. From the access holes in the opposite side of the boom,
relieve the pressure in the lower telescope cylinder by
loosening the bleed plug, (35, Figure 2-44).
5. Unscrew holding valve from its port block. (See
Figure 2-31 and Figure 2-44.)
Installation
1. Check the inside of the port block for any sharp edges or
burrs and remove as necessary with emery cloth.
2. Install new O-rings onto the holding valve.
3. Lubricate the holding valve and O-rings with clean
hydraulic oil.
DANGER
The trombone cylinder must be fully retracted and the
conventional cylinder must be fully extended or retracted
before removal.
WARNING
Pinch Point Hazard!
Before accessing the holding valve install the telescope
hold valve tool to prevent section 3 from retracting into
section 2 when the holding valve is removed. Serious
injury may result.
WARNING
Flying Object Hazard!
The holding valve can fly with explosive force if the
hydraulic pressure is not relieved. Serious injury may
result.
FIGURE 2-30
FIGURE 2-31
Reference Only

Manitowoc Grove TMS800E Specifications

General

Brand	Manitowoc
Model	Grove TMS800E
Category	Construction Equipment
Language	English