Repair of Cummins QSB4.5 Engine in Broderson RT-300-2G Crane

Cummins QSB4.5 Engine Overhaul (Tier 4 Interim) in Broderson RT-300-2G Rough Terrain Crane

The Broderson RT-300-2G rough terrain crane is a compact yet highly efficient machine used in challenging construction and industrial conditions. Equipped with a Cummins QSB4.5 (Tier 4 Interim) engine, it provides high power with low fuel consumption and reliability in demanding lifting operations. Our service was called to perform a comprehensive overhaul of the engine in this machine to restore its full functionality and performance.

Engine Disassembly

The process began with the careful disassembly of the engine from the Broderson RT-300-2G crane. Our service team used the client's available crane to safely lift and disconnect the power unit. All components of the cooling system, air intake, and accessory hoses were secured. Each bolt and connection was thoroughly checked to prevent damage during transport to our headquarters in Kojszówka. The machine was ready for further diagnostics after disassembly.

Engine Verification

After transporting the engine to our workshop, we proceeded with a detailed verification. The identified cause of the overhaul was the wear of the crankshaft and connecting rod bearings, which manifested as knocking sounds and a drop in oil pressure. We conducted an oil analysis, pressure measurement, and visual inspection of the components of the crank-piston system. Minor wear of the piston rings was also noted, confirming the need for a comprehensive regeneration.

Repair Process

Crank-Piston System

We conducted thorough grinding of the crankshaft, replacement of bearings, connecting rods, pistons, and rings. All components were carefully fitted to ensure optimal compression and even engine operation. Each component was cleaned, verified, and assembled according to the manufacturer's standards.

Engine Head

The head underwent full regeneration, including the replacement of valves and guides. We conducted a leak test by submerging it in heated water and a compressed air test to ensure there were no cracks or leaks. All defects were eliminated, and the head components were prepared for assembly.

Fuel System

The injection pump and injectors were tested on a test bench, cleaned, and calibrated. As a result, the engine exhibits even injection and optimal performance with minimal fuel consumption after assembly.

Accessories

The turbocharger, alternator, and starter underwent thorough verification and maintenance. Checking for clearances, sealing, and electrical connections ensures the reliability and safety of the engine's operation in the crane.

Dynamometer Test

The Cummins QSB4.5 engine was started on our dynamometer after the overhaul. The test lasted a minimum of 16 hours under light load of 20-30% of nominal power, followed by full load testing to verify all operating parameters. Thanks to our dynamometer, we could accurately check the engine's responses to various load conditions, monitor temperature, oil pressure, and fuel system performance, ensuring safety and longevity of the unit in the machine.

Installation in the Machine

After completing the tests, the engine was reinstalled in the Broderson RT-300-2G crane. During installation, special attention was paid to the precise connection of all wires, air piping, accessories, and cooling system. Each connection was checked for sealing, and tests were conducted in the presence of the machine operator. After starting, a protocol was created documenting the proper operation of the engine and the absence of leaks, which is standard for our service. The machine was ready for further operation, and we recommend a service inspection after 50 operating hours to maintain the highest reliability.

Summary

The comprehensive overhaul of the Cummins QSB4.5 engine in the Broderson RT-300-2G rough terrain crane restored its full functionality, providing optimal power and reliability. Our mobile service allows for disassembly and assembly at the client's location, and having a dynamometer enables testing under real conditions. As a result, every engine leaving our facility is fully operational, and the client gains confidence that their machine will operate reliably for many months.