Doosan DX235NLC-5 Excavator Service Manual

Table of Contents:-

Safety
1 Track Excavator Maintenance Safety
Specifications
General Maintenance
1 General Maintenance Instructions
2 Standard Torques
Engine
Upper Structure
1 Cabin
2 Counterweight
3 Oil Tank
4 Fuel Tank
5 Main Pump
6 Drive Coupling (Main Pump)
7 Main Control Valve
8 Swing Device
9 Joystick Valve (Work Lever)
10 Dozer Joystick Valve
11 Travel Control Valve (with Damper)
12 Solenoid Valve
13 EPPR Valve (One or Two Way)
14 Accumulator
15 Gear Pump (Rotating)
16 One Spool Valve (Rotating)
Lower Structure and Chassis
1 Swing Bearing
2 Center Joint
2 Center Joint (Dozer)
4 Travel Device
5 Track Assembly
6 Dozer System
Front
1 Boom and Arm
2 Bucket
3 Cylinders
Hydraulic System
2 Hydraulic System Testing and Adjustment
3 Hydraulic System Troubleshooting
9 Electrical System 1 Electrical System
Options
1 One Way
2 Two-way
3 Rotating
4 Quick Coupler
Schematics

Doosan DX235NLC-5 Manual Instruction Extract:

PROCEDURAL TROUBLESHOOTING BASELINE RECOMMENDATIONS
Initial Checks and Tests to Establish Operating Condition of the Excavator Troubleshooting Recommendations
An excavator that fails to deliver designed performance must be checked for the following:
• First hydraulic flow.
• Then hydraulic pressure in a specified order of priority through different points of the system.
To verify adequate available hydraulic flow, before any other tests are performed through the circuit: Check engine operation
• at 1,800 rpm with no load.
• at 1,950 rpm stall load.
If engine rpm drops excessively with a load or fails to surpass rated speed (1,800 rpm), performance problems may be because of inadequate hydraulic flow caused by lagging rotational speed.

NOTE: Verify actual flow on the excavator against rated performance, with a flow meter.
If engine tests meet specifications and adequate torque and horsepower are available at the pump drive flex coupling, pull out the electrical tray under the operator’s seat to inspect the self-diagnostic display.

If the EPOS trouble code display is clear, check hydraulic functions in the following sequence:
• Pilot pressure.
• Negacon, negative control pressure.
• Main relief pressure (front and rear pump) Swing pressure.
• Port relief pressure (individual control functions; boom, arm, bucket, swing, and travel)
• Power boost circuit.
• Standard performance tests; cylinder speed, hydraulic motor (travel and swing) speed, cylinder oil tightness “permissible drift” test.

NOTE: System specification performance tests of individual activator function are determined by flow rate through the component or circuit, not the control pressure or system pressure

How to Use The Doosan DX235NLC-5 Excavator Guide Manual:

This manual provides information for servicing the DX235NLC-5 Doosan Excavator. All service procedures are broken down into detailed steps, listed in their recommended sequence. The manual uses both photographs and drawings to help locate and itemize components. The table of Contents on the preceding pages is your best tool for finding the service procedure you need. Be certain to observe all Safety information included in these pages.

A schematic of each of the major engine systems is provided at the beginning of the section of the manual devoted to troubleshooting and repairing that particular system.

Basic safety precautions are list in the Safety section of the Doosan DX235NLC-5 Excavator Service Manual. Additional safety precautions are list in the Safety section of the owner/operation/maintenance publication. Specific safety warnings for all these publications are provided in the description of operations where hazards exist. WARNING labels have also been put on the product to provide instructions and to identify specific hazards.