Part of the Hyundai Repair Manuals.
All 142 pages of this Hyundai R28-7 (R28-7) Service Manual PDF cover one machine: your R28-7 crawler excavator, from the main pump down to the track rollers. You get full hydraulic schematics, electric circuit diagrams for the starter and alternator systems, and step-by-step teardown procedures for the main pump, control valve, all three pilot valves, slew motor, and travel motor. A full troubleshooting section walks you through travelling and slewing faults, and page after page of maintenance standards backs up every rebuild. Set main relief pressures P1 and P2 to 20.6 MPa, port relief to 23.5 MPa, and confirm unload pump pressure at 2.9 MPa before you button up the hydraulics. No more chasing hydraulic faults with a gauge and a hunch. Bookmarked with a full text layer; download it, pull up any spec by keyword, and get back on the tracks.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Precautions on Maintenance | 6 | Correct Operation, Safety Check, Preparation, Disassembly, Assembly |
| Outline | 7-24 | Location of Serial Number, Name of Each Part, Dimensions and Specifications |
| Attachment | 25-32 | Measuring the Natural Fall of the Attachment, Measuring Attachment Cylinder Speed, Standard of Maintenance |
| Engine | 33-44 | Specification, Inspection and Maintenance Procedures |
| Main Pump | 45-52 | Removing and Installing the Pump, Performance Test |
| Hydraulic Oil Filter | 53-58 | Hydraulic Oil Filter Specifications, Maintenance Procedure |
| Control Valve | 59-66 | Disassembly and Assembly, Structure of the Relief Valve, Precautions for Handling |
| Joystick (Pilot Valve) | 67-69 | Specification, Structure, Joystick Valve Assembly, Casing, Spool |
| Pilot Valve (1) (Travel) | 70-73 | Specification, Structure, Pilot Valve Assembly, Casing, Spool |
| Pilot Valve (2) (Swing, PTO) | 74-77 | Specification, Structure, Pilot Valve Assembly, Casing, Pusher Assembly |
| Pilot Valve (3) (Dozer) | 78-81 | Specification, Structure, Dozer Pilot Valve, Pusher Assembly, Body Assembly |
| Slew Motor | 82-87 | Specification, Structure, Slew Bearing, Slew Case, Relief Valve |
| Travel Motor | 88-93 | Specification, Structure, Hydraulic Motor, Reduction Gear, Pinion Gear |
| Hydraulic Cylinder | 94-99 | Disassembly and Assembly, Assembly Procedures |
| Swivel Joint | 100-103 | Specification, Structure, Swivel Joint Assembly, Cylinder, Slipper Seal |
| Crawler | 104-111 | Crawler (Steel) and Track Frame, Rubber Crawler Total Length 3, 960 Mm and Width X Pitch, Removing and Installing the Crawler, Track Frame Spring |
| Spring Case and Grease Cylinder | 112-115 | Structure, Specification of Spring, Disassembly and Assembly, Adjust Cylinder, Spring Case |
| Idler | 116-117 | Standard of Maintenance, Lubricating Oil |
| Sprocket | 118-121 | Disassembly and Assembly, Removing the Sprocket, Installing the Sprocket, Standard of Maintenance |
| Track Roller | 122-123 | Standard of Maintenance, Lubricating Oil |
| Carrier Roller | 124-125 | Standard of Maintenance, Lubricating Oil |
| Electrical Equipment | 126-129 | Structure and Function, Electric Circuit Diagram, Failure and Remedy, Starter System, Alternator System |
| Troubleshooting | 130-142 | Troubleshooting Procedures, Travelling System Troubleshooting, Slewing System Troubleshooting |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Main relief pressure P1 | 20.6 MPa | p. 24 |
| Main relief pressure P2 | 20.6 MPa | p. 24 |
| Battery | 12V × 50 AH | p. 34 |
| Line filter filtration accuracy | 10µ | p. 55 |
| Line filter proof pressure | 0.7 MPa | p. 55 |
| Suction filter oil temperature | -20°C~120°C | p. 55 |
| Pump weight | 23 kg | p. 46 |
| Pump mounting bolt tightening torque | 90~115 N·m | p. 48 |
| Tightening torque for mounting roller | 325 N·m | p. 123 |
| Hydraulic Oil Tank Capacity | 50.5L | p. 11 |
| Engine Oil Capacity | 4.5L | p. 11 |
| Fuel Tank Capacity | 42L | p. 11 |
