Manitowoc Grove RT770E, Service Maintenance Manual

Page: 63 / 357

2-23
GROVE
RT770E HYDRAULIC SYSTEM
2
Published 11/26/2014, Control # 447-05
PRESSURE SETTING PROCEDURES
The following procedures should be used to properly check,
adjust and set the hydraulic system pressures.
The following equipment is required for checking the
hydraulic pressure settings.
• Pressure Gauge (1) three dial gauge 0 to 34.5 MPa (0 to
5000 psi)
• Accumulator charging and gauging assembly for
20.7 MPa (3000 psi)
• ORFS reducers as required to attach work port hoses to
the gauge.
NOTE: When checking the directional control valve relief
settings, unless otherwise specified, start with the
engine at idle RPM and move the controller to its
fully stroked position. Then slowly accelerate the
engine to the specified RPM. Read gauge and
make adjustments to specified setting.
When checking the outrigger relief valve setting,
start with the engine at idle RPM and activate and
hold the extend or retract switch. Then slowly
accelerate the engine to the specified RPM. Read
gauge and make adjustment as required.
Table 2-2
Valve Pressure Setting Table
Valve To Be Set
Pressure
Setting
MPa (PSI)
Tolerance
MPa (PSI)
Adjustment Location
Load Sense Relief* 27.6 (4000) ±0.4 (±50) Main Control Valve Inlet Gauge Port
Lift Down Relief 13.8 (2000)
+4.8/-0
(+700/-0)
Telescope Retract Relief 24.1 (3500) ±0.4 (±50)
Main Control Valve Telescope Retract
Port
Telescope Extend Relief 18.6 (2700) ±0.4 (±50)
Main Control Valve Telescope Extend
Port
Hoist Raise 24.1 (3500) ±0.4 (±50) Main Control Valve Hoist Raise Port
Hoist Lower 24.1 (3500) ±0.4 (±50) Main Control Valve Hoist Lower Port
Pilot Pressure Supply
2.2 to 3.1
(325 to 450)
within listed
range only
Main Control Valve Inlet
Swing Brake Pilot Supply 1.7 (250) +0.4/-0 (+50/-0) Pressure Reducing Valve
Front Steer Relief Valve 17.2 (2500) ±0.4 (±50) Swing/Steer Control Valve
Swing “Left” Relief 15.2 (2200) ±0.4 (±50) Swing/Steer Control Valve
Swing “Right” Relief 15.2 (2200) ±0.4 (±50) Swing/Steer Control Valve
Outrigger/Rear Steer Relief 17.2 (2500) ±0.4 (±50) Outrigger/Rear Steer Valve Inlet
Service Brake 20.7 (3000) ±0.4 (±50) Service Brake/CAC Fan Valve
Service Brake High Charge Limit 17.4 (2320)
+0.5/-1.0
(+72/-145)
Dual Accumulator Charge Valve
Service Brake Low Charge Limit 13.5 (1950) ±1.0 (±145) Dual Accumulator Charge Valve
Accumulator Pre-Charge 6.2 to 6.6
(900 to 950)
+0.4/-0
(+50/-0)
Accumulator
Charge Air Cooler Fan Motor Relief 6.9 (1000) +.4/-0 (+50/-0) Service Brake/CAC Fan Valve
Counterweight Valve 12.07 (1750) ±0.4 (±50) Counterweight Valve
*This setting is for Boom Lift “UP” Circuit