This is the Caterpillar factory repair set for the 303C CR and 303.5C CR mini excavators, serial prefix DMY00001-Up, with the Mitsubishi S3Q2 and S3Q2-T engines. Cat published these as two-model family books, so one download covers both machines. The part you cannot get anywhere else is the printed wear checks: travel speed over 20 m timed by model and by track type, allowable travel drift of 1000 mm, swing of 90 degrees in 2.5 seconds or less, and cylinder drift limits of 2 mm on the boom and 5 mm on stick and bucket. Add pilot, main and swing relief tests, pump flow testing, engine overhaul, travel and swing motor work, undercarriage service, and the 303.5C CR electrical and hydraulic schematics.
What's Inside This Caterpillar 303C CR, 303.5C CR Repair Manual
| System | Pages | Key Topics |
|---|
| Air Inlet and Exhaust System | 2-11 | Turbocharger, Inlet and Exhaust Manifolds, Air Cleaner |
| Basic Engine | 12-323 | Mitsubishi S3Q2 and S3Q2-T Engines, Cylinder Head, Crankshaft, Pistons |
| Cooling System | 324-347 | Water Pump, Thermostat, Radiator |
| Electrical and Starting System | 348-1148 | Alternator, Starting System, Batteries, Product Link, EquipmentManager, Air Conditioning R134a |
| Engine Arrangement | 1149-1287 | Engine Mounting and Arrangement |
| Frame and Body | 1288-1356 | Frame, Body Panels |
| Fuel System | 1357-1421 | Injection Pump, Injectors, Fuel Filter |
| Hydraulic System | 1422-1965 | Pilot Relief Test and Adjust, Main Relief Test and Adjust, Swing Relief Test and Adjust, Main Pump Flow Test, Cylinder Drift Checks, Travel and Swing Performance Checks |
| Implements | 1966-2023 | Boom, Stick, Bucket, Blade Linkage |
| Lubrication System | 2024-2041 | Engine Oil Pump, Oil Filter |
| Machine Arrangement | 2042-2054 | Machine Arrangement and Layout |
| Operator Station | 2055-2449 | Cab, Controls, Seat |
| Power Train | 2450-2512 | Travel Motors, Swing Motor, Final Drives |
| Service Equipment and Supplies | 2513-2537 | Service Tooling and Supplies |
| Torque Specifications | 2538-2587 | Metric ISO Fasteners, English SAE Fasteners, Fittings, Plugs, Hose Clamps |
| Undercarriage | 2588-2656 | Rubber and Steel Tracks, Idlers, Rollers, Track Tension |
| Work Tools | 2657-2674 | Work Tool Hydraulics and Mounting |
| Schematic | 2675-2710 | 303.5C CR Electrical System Schematic, 303.5C CR Hydraulic System Schematic, Graphic Symbol Legends |
Quick Reference Specifications
| Specification | Value | Page |
|---|
| 303.5C CR |
| Travel speed over 20 m, rubber tracks, 303.5C CR | 14.0 to 16.0 s high, 23.4 to 25.4 s low | |
| Travel speed over 20 m, steel tracks, 303.5C CR | 14.6 to 16.6 s high, 25.4 to 27.4 s low | |
| 303C CR |
| Travel speed over 20 m, rubber tracks, 303C CR | 15.9 to 18.5 s high, 24.5 to 28.0 s low | |
| Travel speed over 20 m, steel tracks, 303C CR | 16.1 to 18.7 s high, 25.8 to 29.1 s low | |
| Cylinder operating speed, boom | extension 2.8 +/- 0.4 s, retraction 3.1 +/- 0.4 s | |
| All Models |
| Travel drift over 20 m | 1000 mm (39.4 in) maximum | |
| Swing time, 90 degrees | 2.5 s or less; 2.8 s or less on a slope | |
| Swing overswing | 180 mm (7.1 in) or less | |
| Machine drift and swing drift on a slope | 0 mm | |
| Cylinder drift, boom | 2 mm (0.1 in) or less | |
| Cylinder drift, stick and bucket | 5 mm (0.2 in) or less | |
| Cylinder drift, blade and boom swing | 2 mm (0.1 in) or less | |
| Serial prefix | DMY00001-Up | |
| Engine fitted | Mitsubishi S3Q2 and S3Q2-T | |
