Manitowoc National Crane NBT40 Series Service Manual

2
NBT40 SERVICE MANUAL HYDRAULIC SYSTEM
National Crane Published 8-01-2017 Control # 287-11 2-1
SECTION 2
HYDRAULIC SYSTEM
SECTION CONTENTS
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Hydraulic System Maintenance Precautions. . . . . . . 2-4
Label Parts When Disassembling . . . . . . . . . . . . . . . 2-4
Welding Precautions . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Parts Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Hydraulic Oil Recommendations . . . . . . . . . . . . . . . . 2-4
Draining and Flushing . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Removing Air From The Hydraulic System . . . . . . . . 2-5
System Description. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Axial Piston Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Main Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Swing Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
RCL Dump Manifold . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Outrigger Control Manifolds. . . . . . . . . . . . . . . . . . . . 2-6
Hydraulic Tank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Hydraulic Remote Controllers . . . . . . . . . . . . . . . . . . 2-7
Hydraulic Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Relief Valve Pressure Setting Procedures . . . . . . . 2-12
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
System Pressure Check . . . . . . . . . . . . . . . . . . . . . 2-13
Hoist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Boom Lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
Telescope In and Telescope Out Reliefs . . . . . . . . .2-13
Outriggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13
Swing Valve Relief . . . . . . . . . . . . . . . . . . . . . . . . . .2-14
Center Front Stabilizer (if equipped) . . . . . . . . . . . . .2-14
Hydraulic Reservoir and Filter. . . . . . . . . . . . . . . . . .2-15
Hydraulic Filter Replacement . . . . . . . . . . . . . . . . . .2-16
Hydraulic Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . .2-17
Oil Cooler Service & Maintenance . . . . . . . . . . . . . .2-17
Hydraulic Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-17
Main Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Hydraulic Remote Controllers . . . . . . . . . . . . . . . . . .2-18
Outrigger Manifolds. . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Holding Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Swing Gearbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Crane Function Power Switch. . . . . . . . . . . . . . . . . .2-18
Hydraulic Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-19
Pump Start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-19
Pump Margin Pressure Setting . . . . . . . . . . . . . . . . .2-20
Maximum Pump Pressure Setting. . . . . . . . . . . . . . .2-20
Load Sense Relief Valve Pressure Setting . . . . . . . .2-20
Trouble Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . .2-22
This section describes the hydraulic system, the
components which make up the hydraulic system, and the
components dependent upon the hydraulic system for their
operation. This includes descriptions of the supply pressure
and return circuit, pumps, valves, and cylinders. Detailed
descriptions and operation of individual hydraulic circuits are
discussed within their individual sections as applicable. A
chart titled Hydraulic Symbols contains all hydraulic symbols
used in the hydraulic schematics contained in this manual.
Reference Only

Manitowoc National Crane NBT40 Series Specifications

General

Brand	Manitowoc
Model	National Crane NBT40 Series
Category	Construction Equipment
Language	English