This is the Cat SIS repair bundle for the 302.5C mini hydraulic excavator, serial prefix GBB - the dealer publications stitched together, not one authored book. The heart of it is the hydraulic section: systems operation plus testing and adjusting, with the actual numbers - main relief at 21700 kPa on P1 and P2, pilot relief at 3400 kPa, cylinder speeds, drift limits, travel and swing times. Around that sit engine testing, cooling, fuel injection, travel motors and final drives, undercarriage, cab, and the named schematic sheets for the 302.5C hydraulic circuit and the 301.6C/301.8C/302.5C electrical system. If you wrench on one of these, or you are about to buy one, this is the checkbook.
What's Inside This Repair Manual
| System | Pages | Key Topics |
|---|
| Air Inlet and Exhaust System | 2-4 | Turbocharger, Exhaust and Air Intake Service |
| Basic Engine | 5-9 | Engine Testing and Adjusting |
| Cooling System | 10-19 | Radiator, Water Pump, Thermostat and Cooling System Service |
| Electrical and Starting System | 20-799 | Starting and Charging System Service (Alternator, Starter, Batteries) with System Schematics; Plus the CAT Add-On Publications Bundled Into This Section: EquipmentManager Dealer and User Guides, Product Link PL522/523 and 121S/300 Telematics, And R134a Air Conditioning and Heating |
| Engine Arrangement | 800-816 | Engine Mounting and Arrangement, Testing and Adjusting |
| Frame and Body | 817-867 | Frame, Covers and Body Panels |
| Fuel System | 868-889 | Injection Pump, Injectors and Fuel System Service |
| Hydraulic System | 890-1307 | Systems Operation, Testing and Adjusting (Travel, Swing and Cylinder Speeds, Drift Checks, Relief Valve Settings, Pilot Accumulator Charging), Pumps, Valves and Cylinders |
| Implements | 1308-1353 | Boom, Stick, Bucket and Blade Linkage Service |
| Machine Arrangement | 1354-1366 | Overall Machine Arrangement, Systems Operation and Testing |
| Operator Station | 1367-1684 | Cab, Seat, Controls and Monitor |
| Power Train | 1685-1724 | Travel Motors, Final Drives and Swing Drive |
| Service Equipment and Supplies | 1725-1741 | Dealer Service Tools and Shop Supplies |
| Undercarriage | 1742-1799 | Track, Rollers, Idlers and Recoil Spring Service |
| Work Tools | 1800-1814 | Work-Tool Mounting and Coupler Service |
| Torque Specifications | 1815-1864 | Cat's Generic Torque Charts (Metric ISO, English SAE, Fittings, Plugs, Hose Clamps) |
| Schematic | 1865-1898 | Named Schematic Sheets - 302.5C Hydraulic System (243-4139-04) and the 301.6C/301.8C/302.5C Electrical System - Plus the Fluid Power and Electrical Graphic Symbol Legends |
Quick Reference Specifications
| Specification | Value | Page |
|---|
| Main relief valve setting (P1 and P2) | 21700 +/- 500 kPa (3147 +/- 73 psi) | p. 1031 |
| Main relief valve setting (P3) | 18050 +/- 450 kPa (2618 +/- 65 psi) | p. 1031 |
| Line relief valve (bucket Close / boom Lower / stick Out) | 25250 +/- 250 kPa (3662 +/- 36 psi) | p. 1042 |
| Pilot relief valve setting | 3400 +/- 200 kPa (495 +/- 30 psi) | p. 1013 |
| Temporary main relief valve setting (test only) | 28950 +/- 250 kPa (4200 +/- 36 psi) | p. 1037 |
| Hydraulic oil temperature for all tests | 55 +/- 5 C (131 +/- 9 F) | p. 985 |
| Cylinder drift wear limit (boom / stick) | 10 mm (0.39 in.) or less | p. 1002 |
| Cylinder drift wear limit (bucket) | 5 mm (0.2 in.) or less | p. 1003 |
| Cylinder drift wear limit (blade) | 3 mm (0.12 in.) or less | p. 1004 |
| Machine drift on a 12 degree slope (wear check) | maximum 30 mm (1.2 in.) | p. 991 |
| Swing drift (maximum) | 120 mm (4.7 in.) | p. 1000 |
| Swing time, 90 degrees | 2.0 seconds or less (left and right) | p. 994 |
| Continuous swing time, 3 revolutions | 18.0 - 22 seconds | p. 994 |
| Swing overswing | 190 mm (7.5 in.) or less | p. 994 |
| Bucket load for swing and drift tests | 105 kg (231.5 lb) | p. 994 |
| Travel time over 20 m measured (high speed) | 17.5 +/- 2.5 seconds forward and reverse | p. 987 |
| Travel time over 20 m measured (low speed) | 26.0 +/- 1.5 seconds forward and reverse | p. 987 |
| Travel deviation over the measured distance | 1500 mm (59 in.) or less | p. 987 |
| Track speed, 3 revolutions (high / low) | 9.7 +/- 1.5 s / 15.7 +/- 1.5 s | p. 985 |
| Cylinder speed (boom extension) | 2.5 +/- 0.5 seconds | p. 1010 |
| Cylinder speed (stick extension / retraction) | 3.0 +/- 0.5 seconds | p. 1010 |
| Cylinder speed (bucket extension / retraction) | 2.2 +/- 0.4 s / 2.9 +/- 0.3 s | p. 1010 |
| Cylinder speed (blade extension / retraction) | 1.1 +/- 0.2 seconds | p. 1010 |
| Cylinder speed (boom swing extension / retraction) | 6.7 +/- 1.4 s / 5.8 +/- 1.4 s | p. 1010 |
| Pilot accumulator nitrogen purity | 99.8 percent | p. 1016 |
| Pilot accumulator charge pressure (varies with ambient) | 1490 kPa at -25 C rising to 1940 kPa at 50 C (full table in the manual) | p. 1024 |
| Accumulator pilot pressure with oil exhausted | 860 kPa (125 psi) | p. 1023 |
| Bucket control linkage pin height for the drift test | 720 mm (28.3 in.) | p. 990 |
