Part of the Doosan Repair Manuals.
Doosan publication 950106-00437E is the factory shop manual for the DL420-3 wheel loader, serial 10001 and up. It is written around this machine's Scania DC13 Tier 4i engine with XPI injection and the ZF 4WG-260-4 power shift, with the 5WG-260 option also covered.
Say the transmission abnormal light comes on and the display lists a malfunction starting with T. The ZF fault code table tells you what that code means, what the TCU did and where to start the repair. The book also covers the ZF axles, wet disk brakes, steering, articulation center, main control valve, pump and the full hydraulic and electrical schematics.
You buy it once. It stays with this loader for as long as you run it.
What's Inside This Doosan DL420-3 Manual
| System | Pages | Key Topics |
|---|---|---|
| Safety | 5-70 | Wheel Loader Safety Precautions, Operation and Maintenance Warnings |
| Specifications | 71-88 | General Specifications, Engine Performance Curves, Working Range and Dimensions for the DL420-3 |
| General Maintenance | 89-126 | General Maintenance Instructions, Standard Torques |
| Engine | 127-358 | Scania DC13 Engine Service, Engine Coolant Heater (Option) |
| Transmission and Torque Converter | 359-690 | ZF 4WG-260-4 Power Shift Transmission and ZF 5WG-260 (Option) with Torque Converter |
| Transmission Error Codes (ZF) | 691-720 | TCU Modes, Table of ZF Fault Codes with Meaning, TCU Reaction and Possible Steps to Repair |
| Axles and Driveshaft | 721-864 | ZF MT-L 3085 II / 3095 II Front Axle, ZF Multitrac MT-L 3105 II Rear Axle, Driveshaft |
| Brake | 865-920 | Service Brake, Supply Valve, Charging Block, Parking Brake, Brake Pedal Valve, Accumulator |
| Steering | 921-1016 | Power Steering System, Steering Unit, Steering Pump, Flow Amplifier, Jerk Softener, Emergency Steering |
| Frame and Tanks | 1017-1050 | Articulation Center, Counterweight, Oil Tank, Fuel Tank |
| Hydraulics | 1051-1161 | Main Pump, Main Control Valve, 3rd Control Valve (Option), Load Isolation System, Cooling System, Pilot System, Hydraulic Schematic |
| Electrical System | 1162-1300 | Air Conditioner, Electrical System and Display, Warning Lights, Electrical Schematic |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Standard bucket capacity (BOT / BOC) | 4.0 m3 (5.2 yd3) / 4.2 m3 (5.5 yd3) | p. 80 |
| Vehicle weight | 23,000 kg (50,700 lb) | p. 80 |
| Engine maker and model | SCANIA / DC 13 | p. 80 |
| Engine emission | US EPA Tier 4i (EU Stage IIIB) | p. 80 |
| Injection system | Extra high-pressure fuel injection system, XPI | p. 80 |
| Rated gross power | 264 kW (354 HP) @ 1,800 rpm (SAE J1995) | p. 80 |
| Max torque | 155.2 kg•m / 1,400 rpm (1,123 ft lb @ 1,400 rpm) | p. 83 |
| Transmission | Full Automatic Power Shift, 4 Forward, 3 Reverse (Option 5 Forward, 3 Reverse) | p. 80 |
| Travel brakes | 4 Wheel, Wet Disk | p. 80 |
| Parking brake | SAHR, Dry Disk Type | p. 80 |
| Travel speed, 4 speed | 6.5 (4.0) / 12.2 (7.6) / 18.5 (11.5) / 36 (22.4) kph (MPH) | p. 80 |
| Steering angle | ±40° | p. 80 |
| Rated operating load | 8,200 kg (18,080 lb) | p. 80 |
| Maximum breakout force (bucket) | 210 kN (47,210 lb.f) | p. 80 |
| Maximum gradeability | 27° (51%) | p. 80 |
| Wheel base | 3,500 mm (11' 6") | p. 85 |
Doosan DL420-3 Common Problems This Manual Covers
Transmission drops to neutral without warning and the display shows a T malfunction
Look the code up in the ZF fault code table. For code 11, a logical error at the gear range signal, the TCU forces neutral. Check the cables between the TCU and shift lever, then check the signal combinations as the repair steps lay out.
Manual Section: Transmission Error Codes (ZF) p. 698Buzzer sounds for several seconds right after the engine starts
The warning lights section explains that the buzzer sounds for 8 seconds when engine oil pressure drops below 0.7 bar after start-up. Shut the engine down and check the oil level. Then work through the Scania DC13 service procedures in the Engine section before running the loader again.
Manual Section: Electrical System / Engine p. 1225Parking brake will not hold properly after new linings or disks are fitted
The Brake section requires a parking brake basic setting after new lining plates or brake disks go in, and any time braking performance is poor. Let the brake cool fully first. Then set the rated clearance with the adjusting screw, 1.0 mm on the small type.
Manual Section: Brake p. 899Vibration or unusual noise from the hydraulic system while cycling the lift arms and bucket
The manual names air leaking into the hydraulic circuit or a defective pump as likely causes. Pull the main pump drain plugs and check for grit or metallic particles. Then use the main pump, main control valve and pilot system pages, along with the hydraulic schematic, to trace the fault.
Manual Section: Hydraulics p. 99Frequently Asked Questions
My DL420-3 dropped into neutral and is showing ZF fault code 11. What is it?
Code 11 is a logical error at the gear range signal. The TCU reacts by shifting the transmission to neutral. The repair steps tell you to check the cables from the TCU to the shift lever and check the signal combinations. The table covers both the 4WG and 5WG versions and applies to ZF software V 53.x through V58.0. p. 698
The transmission warning light is on. How do I find out what actually failed?
Go to the current malfunction information on the display and look for entries that begin with T. Those are transmission faults. Take that code to the ZF fault code chapter, where each one is listed with its meaning, the TCU reaction and possible repair steps. That one table is reason enough to own the book. p. 1225
Does it cover the optional 5-speed transmission or just the 4-speed?
It covers both. The transmission chapter deals with the ZF 4WG-260-4 four speed and the ZF 5WG-260 five speed option, each with its torque converter. The ZF fault code table is also written for both versions, so a 5 forward, 3 reverse machine is covered too. p. 361
When does the parking brake need its basic setting done?
Do it whenever you fit new brake lining plates or brake disks, or when braking performance falls short. The DL420-3 uses a SAHR dry disk parking brake. Work with the brake cold and set the rated clearance with the adjusting screw, 1.0 mm on the small type. p. 899
The loader hydraulics vibrate or make an odd noise under load. What should I check first?
The manual points to two causes: air getting into the hydraulic circuit, or a failing pump. Open the main pump drain plugs and look for grit or metal particles. From there, the Hydraulics chapter takes you through the main pump, main control valve, pilot system and hydraulic schematic. p. 99
