Manitowoc Grove TMS9000-2 Series, Руководство по обслуживанию

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Published 01-14-2021 Control # 707-01
HYDRAULIC SYSTEM TMS9000-2 SERVICE MANUAL
PILOT OPERATED CHECK VALVE
Description
A pilot operated (PO) check valve 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.
Internal Leak Testing
This procedure is to be used to determine if the outrigger
stabilizer cylinder has an internal seal leak, a leaking PO
check valve or if it is thermal contraction.
Check Cylinder for Internal Piston Seal Leak
With machine set up on outriggers remove the rod side
cylinder hose from the suspected leaking stabilizer cylinder.
(See Figure 2-14).
Oil will flow until the cavity in the cylinder port block empties.
Once the port block cavity empties, oil should stop flowing
from the rod side port.
If oil stops flowing, the cylinder’s internal piston seal is
sealing properly.
If oil continues to flow out the rod port, the cylinder’s internal
piston seal is leaking.
After determining the condition of the cylinders internal
piston seal leave the rod side hose disconnected and
continue to test the PO check valve.
Test PO Check Valve For Leakage
Remove the piston side hose from the port block of the
cylinder. (See Figure 2-14).
A small amount of oil will flow out and then stop.
If oil stops flowing, the cylinder’s PO check valve is sealing
properly.
If oil continues to flow out the piston port, the cylinder’s PO
check valve is leaking.
If oil flow is not noticed from either port then the cylinder and
PO check valve are functioning properly and any cylinder
contraction during normal operation can be attributed to
thermal contraction of the oil.
CAUTION
Machine Damage!
Perform the following procedure with the crane set up on
outriggers and the boom in the boom rest and the boom
extension stowed. Only remove the hoses from one
cylinder at a time.
Piston Port
Rod Port
9249
FIGURE 2-14
CAUTION
Personal Injury Hazard!
Release hose to adapter connection slowly. Trapped
pressure may exit between the outrigger cylinder and the
work port PO check valves in the outrigger selector valve.
Hydraulic oil is under pressure that can cut and inject into
the skin.
Always wear gloves when working with hydraulic system
components.
CAUTION
Personal Injury Hazard!
Release hose to adapter connection slowly. Trapped
pressure may exit between the outrigger cylinder and the
work port PO check valves in the outrigger selector valve.
Hydraulic oil is under pressure that can cut and inject into
the skin.
Always wear gloves when working with hydraulic system
components.
Fo
r
Reference
Only