Pilot Operated Check Valve; Description; Maintenance - Manitowoc Grove TMS700E Service And Maintenance Manual

HYDRAULIC SYSTEM

PILOT OPERATED CHECK VALVE

Description

A pilot operated (PO) check valve (Figure 2-27) is located in
each outrigger jack cylinder port block. The check valve
functions as a holding valve for the jack cylinder. Oil flow is
directed from the "V" port to the "C" ports, while blocking flow
in the opposite direction. Flow is reversed from "C" to "V"
when pressure pilot oil is applied to the opposite side "V"
port.

Maintenance

Removal
1. Unscrew the check valve from the jack cylinder port
block.
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 check valve.
Item

Description

1 Port C - Cylinder
2 Port P - Pilot
3 Port V - Valve
6155
2-40
3. Lubricate the check valve and O-rings with clean
hydraulic oil.
Do not damage the O-rings during installation of the check
valve. If the check valve turns freely then gets hard to turn,
then easy to turn; remove the check valve and check the
O-rings. They have probably been damaged by a sharp
edge of a port.
NOTE:
4. Carefully install the check valve into the port block until
fully seated.
5. Test the check valve and port block by operating the
affected outrigger's jack cylinder. Verify it extends and
retracts without problems; verify there is no leaking.
Make repairs as needed.
2
Published 01-29-2015, Control # 512-01
TMS700E SERVICE MANUAL
CAUTION
The check valve should turn by hand until
compression of the O-rings begins.
1
3
6155
FIGURE 2-27