Caterpillar 307C Mini Hyd Excavator Service Repair Manual
307C Hydraulic Excavators
The C Series incorporates innovations for improved performance and versatility.

Pistons. Heat resistant aluminum alloy pistons have a short compression height, reducing weight and improving efficiency. The piston ring set consists of three rings, which are treated for wear resistance. Caterpillar 307C Mini Hyd 

Low Fuel Consumption. The 4M40-E1 engine features low fuel consumption, improved thermal efficiency and reduced friction resistance between piston and liners.

Maintenance. To make daily maintenance easy, the oil level gauge,oil filter, fuel filter and priming pump are located on the left side of the engine.

Crankshaft. For durability and high reliability the surface of the crankshaft journals and pins are induction hardened to reduce wear.

Cooling. A large diameter fan and full length, water-cooled engine cylinders, combined with excellent thermal efficiency, help prevent overheating, prolong engine life and ensure the
ability to operate at high temperatures and under heavy loads.