Repair of the Cummins QSB4.5 Engine in the Terex CD225-1 Crane

Engine overhaul of Cummins QSB4.5 (Tier 3) in the Terex CD225-1 rough terrain crane

Introduction

A Terex CD225-1 rough terrain crane equipped with the popular Cummins QSB4.5 (Tier 3) diesel engine arrived at our service. This is a compact yet extremely durable model of rough terrain crane, widely used on construction sites and in industrial plants. The Cummins QSB4.5 engine, known for its high work culture and low fuel consumption, plays a key role in this machine, ensuring stable operation of the lift and the efficiency of the entire hydraulic system.

The operator reported a significant loss of power, difficulty starting, and excessive white smoke. Our mobile service team went to the client in the Katowice area (Silesian Voivodeship), where we conducted preliminary diagnostics on the machine. After performing the necessary tests, we determined that a complete disassembly and overhaul of the engine was necessary at our facility in Kojszówka.

Preliminary diagnostics in the machine

During the initial inspection, we conducted a compression test and exhaust gas analysis. The results clearly indicated a cracked head or a leak in the cooling system, which was confirmed by the white smoke and the presence of exhaust gases in the cooling system. The CO2 test clearly showed a blow-by into the cooling system. To rule out possible damage to the block or cylinder liners, a complete disassembly of the engine was necessary.

Engine disassembly

The engine disassembly was performed on-site at the client's location with the help of a crane provided by the machine's user. Our mechanics disconnected all hoses, electrical installations, engine mounts, the intake system, and components of the cooling system. Everything was secured, and the engine was transported to our facility in Kojszówka. We always ensure proper labeling and securing of each part so that all components can be reassembled according to factory tolerances.

Verification of engine components

In our workshop, the engine was completely disassembled, and each part was subjected to detailed verification. The head underwent a leak test – submerged in heated water and subjected to pressure, it revealed cracks between the water channels. We checked the crankshaft (measuring the crankshaft and journal runout), connecting rods, cylinder liners, and the camshaft. Additionally, the turbocharger was verified for axial and radial play, and the fuel pump, which ultimately went for regeneration at an external facility.

Regeneration and repair

Crankshaft-piston system

We performed honing of the liners, replacement of pistons, rings, and main and connecting rod bearings. The crankshaft was ground according to Cummins standards. The connecting rods were checked for twisting and bending – some of them required correction.

Engine head

Due to the detected cracks, the head underwent complete regeneration: machining, replacement of guides, valves, and rechecking for leaks. After the process, all parameters were within the range required by Cummins.

Fuel system

The fuel pump was regenerated, and the injectors were tested on a test bench. Two of them required replacement due to improper opening pressure.

Accessories

The turbocharger was regenerated, and the alternator, starter, and all electro-mechanical components were checked. Oil hoses, part of the intake piping, and components of the cooling system were also replaced.

Engine installation

The installation of the Cummins QSB4.5 engine in the Terex CD225-1 crane was carried out on-site at the client's location. Our mobile service brought the engine after the overhaul, carefully secured for transport. The installation process involved precisely positioning the unit in the engine compartment using the client's crane, connecting all fuel, electrical, hydraulic, and intake hoses. We ensured the replacement of filters, venting of the fuel system, setting up the intake hoses, and checking the tightness of connections under pressure.

After installation, we conducted a full functional test together with the machine operator. The engine's response to load, stability during load lifting, proper operation of the hydraulic system, and absence of leaks were checked. After a successful test, the installation protocol was signed.

Engine dynamometer test

One of the greatest advantages of WIBAKO is our own engine dynamometer, which allows us to test the unit under full load range before installation in the machine. The Cummins QSB4.5 engine ran for a total of 16 hours under preliminary loads of 20-30 percent, which allowed us to check the stability of parameters, oil pressure, operating temperature, and system tightness. We then conducted a series of full load tests, simulating working conditions in the Terex CD225-1 rough terrain crane. The tests confirmed the engine's full efficiency in terms of power, torque, and combustion uniformity. The dynamometer allows us to detect even minimal irregularities before installation, ensuring maximum operational safety and quality assurance for the client.

Engine maintenance after overhaul

The engine after the overhaul is covered by WIBAKO's warranty. We recommend the first filter change after 50 operating hours, which our service will perform at the client's location. During the first inspection, we check the engine's operating condition, system tightness, and the overall condition of the accessories. Subsequent inspections are performed every 250 operating hours or every 3 months.

Where the Cummins QSB4.5 engine is used

The Cummins QSB4.5 engine is used in many construction machines: loaders, rough terrain cranes, telehandlers, agricultural machines, and mining equipment. Its popularity stems from its reliability and the wide availability of parts.

Summary

Thanks to WIBAKO's comprehensive approach, professional technical background, and advanced engine dynamometer, the Terex CD225-1 rough terrain crane has regained full efficiency. The client received a machine ready for work, and we provided service support for the coming months. The next inspection is scheduled for 50 operating hours.