Renovation of the Deutz TCD 7.8 L6 Engine in the Fuchs MHL 350 F Excavator

Overhaul of the Deutz TCD 7.8 L6 Engine in a Fuchs MHL 350 F Material Handler

The Fuchs MHL 350 F is a machine designed for intensive material handling work, where the powertrain must provide stable performance during long hours of operation. In this case, the subject of the service work was a Deutz TCD 7.8 L6 engine, a 6-cylinder diesel engine installed in the Fuchs material handler. The engine was sent for overhaul due to natural wear resulting from long-term operation.

In engines operating in construction and material handling machinery, gradual wear of individual components can lead to deterioration in the performance of the entire machine. For this reason, before starting an overhaul, it is necessary to accurately determine the condition of the power unit. In the case of the Fuchs MHL 350 F, the first stage involved diagnostics of the engine while it was still installed in the machine. Our mechanics then removed the unit using a crane provided by the customer and prepared the engine for transport to our headquarters in Kojszówka.

The work was carried out as part of Deutz diesel engine service. The scope included diagnostics, disassembly, detailed inspection of components, repair of elements requiring intervention, reassembly of the engine, load testing on an engine dynamometer and preparation of the unit for reinstallation in the machine. This approach makes it possible to check the engine not only during unloaded operation, but also under conditions corresponding to the actual workload of the unit.

Initial Diagnostics of the Deutz TCD 7.8 L6 Engine Before Removal

Before removing the engine, our mechanics began with basic diagnostics of the unit installed in the Fuchs MHL 350 F. With an engine whose wear had increased over its operating life, it was important to check the basic operating parameters and gather information that would allow us to determine whether a comprehensive overhaul was required.

First, we assessed the way the engine started, its operation after reaching operating temperature and its behavior when the load changed. Parameters related to the lubrication and cooling systems were also assessed. In the case of an engine with high operating hours, it is particularly important to compare the observed symptoms with the nominal operating characteristics of the unit.

The next stage was an assessment of possible wear in the crankshaft and piston system. Natural wear of cylinders, pistons, rings, liners or bearings can result in a gradual loss of engine performance. Diagnostics of this area may include compression measurements and cylinder leak testing. In the case of the overhauled Deutz TCD 7.8 L6, the final assessment of the components was carried out after disassembly and detailed measurement of the individual parts.

This type of diagnostic process prevents the scope of the overhaul from being determined solely on the basis of symptoms observed while the engine is installed in the machine. In the case of Deutz engines operating in material handling machinery, it is important to inspect all components that may affect the durability and correct operation of the entire unit.

Removal of the Deutz Engine from the Fuchs MHL 350 F

After completing the initial diagnostics, we proceeded with the removal of the Deutz TCD 7.8 L6 engine from the Fuchs MHL 350 F material handler. Removing an engine from this type of machine requires appropriate preparation of the work area and protection of the components that remain in the machine.

The removal work is always carried out using a crane provided by the customer. Before lifting the engine, the mechanics disconnect the components required for safe removal of the unit from the engine compartment. Connections, components of the engine equipment and mounting points are disconnected as necessary. Particular attention is paid to the cooling system hoses, air intake system and other connections, which must be properly protected against contamination or damage.

Preparing the engine for transport is also an important stage. Once all necessary connections and mounts have been disconnected, the unit is safely lifted and removed from the machine. The Deutz TCD 7.8 L6 engine is then prepared for transport to our headquarters in Kojszówka, where the detailed inspection and overhaul are carried out.

Our service also performs engine removal and installation as part of our mobile service. This means that when machines are operating away from our headquarters, our mechanics can travel to the customer, carry out the necessary work on site and prepare the engine for transport. In the case of the Fuchs MHL 350 F, the removal was carried out at the machine's operating site in the Kraków area.

Inspection of the Deutz TCD 7.8 L6 Engine in the Workshop

After the engine was delivered to our headquarters, a detailed inspection of the unit began. The engine was dismantled into individual components, with the removed parts being cleaned and inspected by our mechanics on an ongoing basis. Inspection is one of the most important stages of an overhaul because only after measurements have been performed can we determine which components can be reused, which require reconditioning and which must be replaced.

In the case of the Deutz TCD 7.8 L6, particular attention was paid to the crankshaft and piston system. The crankshaft was inspected, including its visual condition, possible signs of overheating and wear, runout and journal dimensions. The oil passages were also checked. Connecting rods were inspected for wear, cracks and signs of overheating, while their geometry and fastening components were also checked.

The pistons, rings, cylinder liners and bearings were also inspected. Wear of these components is a natural phenomenon during long-term engine operation, but exceeding the permitted parameters means that appropriate repair work is required. Based on the measurement results, the scope of the overhaul can be properly selected.

The camshaft was also inspected. Our mechanics carried out a visual inspection and measured the working surfaces and cam lobes. The engine head components were also checked, including valve seats, valves and guides. The cylinder head underwent a leak test. This process consists of immersing the head in heated water, connecting compressed air and observing whether air escapes from the inspected component, which could indicate a leak or crack.

The engine accessories were inspected as well. The turbocharger was checked for axial and radial play. If necessary, individual components were sent for further reconditioning. Similarly, where diagnostic results indicated the need for additional inspection of the fuel system, its components could be tested on specialist equipment.

Repair of the Deutz TCD 7.8 L6 Crankshaft and Piston System

After completing the inspection, the scope of repair work for the Deutz TCD 7.8 L6 engine could be determined. In a unit that has operated for a long period, restoring the correct condition of the components responsible for combustion and transferring force from the pistons to the crankshaft is particularly important.

The entire crankshaft and piston system is inspected as part of the work. The crankshaft is carefully measured and, if wear is identified, appropriate reconditioning can be carried out, including crankshaft grinding. The journals and oil passages are inspected. Proper preparation of the surfaces working with the bearings is also important.

The connecting rods and their connections are inspected. Their geometry, surface condition and fastening components are checked. The condition of the pistons, rings and cylinder liners is then assessed. Components that do not meet the required parameters are replaced. Other components can be reused after appropriate preparation.

Work on the crankshaft and piston system requires the correct assembly sequence and dimensional control. During an overhaul of the Deutz TCD 7.8 L6, the objective is not simply to replace worn parts. Correct matching of all components and checking their interaction after assembly are equally important.

Deutz Engine Cylinder Head Reconditioning

The next area of work was the cylinder head of the Deutz TCD 7.8 L6 engine. Its condition directly affects cylinder sealing, correct gas exchange and the combustion process. For this reason, before reinstallation, the cylinder head is carefully inspected to determine whether it can continue to be used.

The scope of cylinder head reconditioning depends on the inspection results. The work may include cylinder head resurfacing and, depending on the degree of wear, replacement of valve guides and valves. Valve seats and clearances are also checked. After the work is completed, the cylinder head undergoes another leak test.

The leak test is particularly important during an engine overhaul because it makes it possible to identify problems that cannot always be clearly detected during a visual inspection alone. The cylinder head is immersed in heated water and compressed air is introduced into the appropriate passages. Observing any escaping air makes it possible to assess the tightness of the component.

Fuel System and Engine Accessories

During the overhaul of the Deutz TCD 7.8 L6, the components responsible for preparing the engine for operation are also inspected. In the case of the fuel system, correct operation of the components responsible for delivering fuel to the cylinders is essential. If diagnostics indicate that additional inspection of the injection pump is required, it can be tested on a specialist test bench.

The engine accessories are also inspected. The turbocharger is checked for axial and radial play. Electrical and electromechanical components, including the starter motor and alternator, are also inspected. The scope of work depends on the condition of the individual unit and the results of measurements performed during the overhaul.

This approach helps prevent situations where a problem remains in one of the engine accessories after the engine has been reassembled. Comprehensive inspection is particularly important when the engine is going to return to intensive work in a material handling machine.

Professional Assembly of the Deutz TCD 7.8 L6 Engine

After all repair work had been completed, the engine assembly process began. Reassembling an engine after an overhaul requires precision because all previously inspected components must be correctly combined into one complete unit. Our mechanics prepare the individual components, check their condition and carry out the assembly in accordance with the adopted repair procedure.

Particular attention is paid to the crankshaft and piston system. The crankshaft, bearings, connecting rods, pistons and other components must be correctly prepared for operation together. Further components, including the cylinder head and engine accessories, are then installed.

Proper preparation of the external connections is also an important part of the process. Before installation in the machine, hoses and components that will later work with the cooling system, air intake and other Fuchs MHL 350 F systems are inspected. This helps reduce the risk of problems during the subsequent engine start-up.

Once the Deutz TCD 7.8 L6 engine has been assembled, it is ready for start-up and testing. However, before it returns to the machine, we test the unit on an engine dynamometer. This is one of the important elements of the overhaul process because it allows us to verify the behavior of the engine under load.

Testing the Deutz TCD 7.8 L6 Engine on an Engine Dynamometer

An engine dynamometer makes it possible to test the power unit under controlled load conditions before it is reinstalled in the machine. This is important because a rebuilt engine does not have to be installed immediately in the machine to determine how it behaves under load.

For engines after an overhaul, the test begins by starting the unit and operating it under light conditions. The engine runs for a minimum of 16 hours at approximately 20-30% of its nominal load. This stage allows us to observe the behavior of the unit during the first hours of operation after the overhaul. Basic operating parameters and the engine's behavior as temperature and operating time increase are monitored.

If the engine maintains its basic operating parameters during this period, the next stage of testing can begin. The unit is repeatedly loaded over a wider range. This makes it possible to check the engine under conditions requiring greater effort. For a Deutz TCD 7.8 L6 engine intended for a Fuchs MHL 350 F, this is particularly important because the engine in a material handler can operate under significant load for extended periods.

Dynamometer testing also allows the engine to be monitored without the need to operate the entire machine at the same time. Our mechanics have better access to the unit and can monitor its behavior during successive test stages. If any irregularity occurs, the test can be stopped and the relevant area of the engine inspected again.

An important part of the test is observing the engine during changes in load. The engine should not be assessed only while operating without load. A load test makes it possible to determine how the unit behaves under conditions closer to those that will occur after it has been installed in the machine.

The engine dynamometer is also important from the perspective of installation safety. If the engine successfully passes testing before installation in the Fuchs MHL 350 F, the number of unknown factors during the first machine start-up is reduced. This does not eliminate the need for post-installation checks. After the engine is installed, all connections and the interaction between the engine and the machine systems must be checked again.

For this reason, the dynamometer test is treated as an integral part of the overhaul rather than an additional check carried out only for reference. It helps confirm the correct operation of the rebuilt Deutz TCD 7.8 L6 before the unit proceeds to the next stage of the work.

Installation of the Engine in the Fuchs MHL 350 F

After the dynamometer tests were completed, the Deutz TCD 7.8 L6 engine was prepared for reinstallation in the Fuchs MHL 350 F material handler. Engine installation requires the same level of precision as its removal. The rebuilt engine must be correctly positioned in the engine compartment, secured and connected to all machine systems.

The crane provided by the customer is again used to position the engine in the machine. Our mechanics control the position of the unit while it is being lowered to prevent damage to hoses, engine accessories or other components located in the engine compartment. Once the engine is correctly positioned, its mounts are installed and the remaining connections are made.

Correct connection of the air intake system is particularly important. The air hoses must be installed in a way that ensures the tightness of the entire system. The cooling system hoses and other components disconnected during removal are also checked. Each connection must be properly prepared and secured.

After the engine has been mechanically secured, the remaining systems are connected. The engine is then prepared for its first start-up. As part of the machine preparation, filters and other components required for safe engine operation are checked.

Once the engine is started, our mechanics monitor its operation and check the tightness of all connections. The inspection does not end with the initial start-up. It is important to observe the engine after it reaches operating temperature and during machine operation.

The machine operator also participates in the tests. This allows us to check how the rebuilt engine cooperates with the other systems of the Fuchs MHL 350 F under operating conditions. Machine tests are carried out while monitoring the engine's response to changes in load and the behavior of the complete powertrain.

A successful test also includes checking that there are no leaks and that all connections remain tight. Once the installation work and tests have been completed, a report confirming the correct installation is prepared.

Engine Service After the Overhaul

The overhaul of the Deutz TCD 7.8 L6 engine does not end when the Fuchs MHL 350 F is started. The first hours of operation after an overhaul are a period during which monitoring of the engine and all components working with it is particularly important.

We recommend carrying out the first inspection after 50 operating hours. The inspection is performed by our mechanics at the customer's site. It is not limited to changing filters. The general condition of the engine accessories, the connections between the engine and other machine components and the correct operation of the unit are also checked.

The 50-hour inspection also makes it possible to determine whether any leaks or other irregularities have appeared during normal operation that were not present during the tests carried out immediately after installation. This is an important part of post-overhaul engine service.

Further inspections are recommended every 250 operating hours, but no less frequently than once every 3 months. Regular servicing makes it possible to monitor the condition of the engine and respond to any irregularities at an early stage.

Machines Using the Deutz TCD 7.8 L6 Engine

The Deutz TCD 7.8 L6 is a 6-cylinder diesel engine used in machines requiring an appropriate level of performance and durability from the power unit. In the case described here, the engine was installed in a Fuchs MHL 350 F, a machine designed for intensive material handling operations.

When diagnosing an engine or ordering parts, it is important to identify the exact engine model. The Deutz brand alone may not be sufficient for correct parts selection. Engine identification data, information from the engine nameplate and the serial number are useful for accurately identifying the specific engine version and determining the appropriate parts or service requirements.

WIBAKO performs overhauls and repairs of diesel engines used in construction machinery and other off-highway machines. If a Deutz TCD 7.8 L6 engine requires diagnostics or an overhaul, it is worth providing the engine identification data together with information about the machine in which it operates. This makes it possible to properly prepare the scope of work before the repair begins.

Summary of the Deutz TCD 7.8 L6 Overhaul in the Fuchs MHL 350 F

The overhaul of the Deutz TCD 7.8 L6 engine operating in the Fuchs MHL 350 F material handler included the complete process, from diagnostics in the machine, through removal and inspection of the components, to repair, assembly and testing of the unit.

A key element of the entire process was the detailed inspection of the components after the engine had been dismantled. This made it possible to determine the actual condition of the crankshaft and piston system, cylinder head and accessories and select the scope of work appropriate to the degree of wear.

The engine dynamometer test was another important stage. By operating the engine under controlled load, its behavior could be checked before it was reinstalled in the Fuchs MHL 350 F. After the test was completed, the engine was installed in the machine, followed by tests involving the operator and a check of the tightness of all completed connections.

WIBAKO provides diesel engine service and construction machinery service, carrying out both workshop-based work and mobile service operations. When a Deutz engine requires an overhaul, our mechanics can carry out the removal and installation of the unit at the customer's site, while the engine itself can be transported to our headquarters in Kojszówka.

After the overhaul and installation, we recommend the first inspection after 50 operating hours. Further inspections should be carried out every 250 operating hours, but no less frequently than once every 3 months. Regular servicing makes it possible to monitor the condition of the engine and its interaction with the other machine components.

Construction machinery service - learn more about the services provided by WIBAKO.

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