During the operation, in addition to the general wear of the vehicle, there is also the wear of individual subsystems. One of the most important subsystems, that due to wear during operation, leads to poorer engine performance is the fuel preparation system, in our case the Common rail system. Thus, for example, the wear of the C-R fuel injector manifests itself as improper engine operation, appearance of black or white exhaust fumes, difficult engine start, etc.
Poor operation of C-R fuel injectors occurs due to a number of reasons, starting with the formation of hard deposits in the injectors that forms in conditions of high pressure and temperature as impurities contained in the fuel excrete, worn surfaces of the injector nozzles and valve sets, but also as an internal mechanical damage to the aformentioned injector parts, as a result of micro-abrasion caused by hard micro-particles of the bearing surfaces of the pump elements, or the bearings of the pump drive shaft of the high-pressure C-R fuel pump, that became loose due to wear.
By diagnosing the vehicle, it is possible to detect the malfunction of the engine, the fuel system, and to a limited extent also the C-R injectors, with additional workshop tests that enable the comparison of fuel return flows between the injectors. Often, the information gathered in this way is sufficient to make a decision on the replacement of the injectors, starting from the assumption that the malfunction of the injectors was caused by wear in normal operating conditions of the vehicle. However, it is often neglected to determine the true state of wear of a high-pressure fuel pump if it meets the criteria of the basic workshop tests that are provided in case of fuel system failures.
Thus, the high pressure C-R pump can achieve the required pressure and flow, have a satisfactory regulation/metering of fuel pressure/fuel flow, and at the same time due to the wear of the pump elements and bearings, separation of microparticles can go unnoticed. This can lead to pump failure, and injector failure as well, and the need for a major overhaul of the complete fuel system. Thus, in a short time the fuel system failure repeats, but this time on a larger scale.
One way to reduce the likelihood of such an event is to check the appearance of the metering unit and the fine fuel filter if small metal particles have been accumulated, and another, a more reliable way, is to dismantle the pump and inspect all the parts in a disassembled condition.
Although the estimated working lifetime of the C-R fuel injection systems, according to, for example the manufacturer Bosch, should on passenger cars reach 300,000 km, light commercial vehicles 400,000 km, medium-duty commercial vehicles 750,000 km, heavy commercial vehicles 1,600,000 km, working machines 12,000 - 15,000 working hours, in most cases the actual durability of the C-R fuel system has been shown to be significantly shorter and is generally limited by the quality of maintenance and fuel that is burnt.
Therefore, it makes sense to take into account all risks at the first signs of wear and consider the option of a complete overhaul of the C-R fuel system, as in the case of partial repair the vehicle can be on the road relatively quickly, but the risk of subsequent failure in case of excessive wear of the high pressure fuel pump can´t be eliminated. Although it is possible to point out worn-out components with a systematic approach, the fact is that in most cases all components of the C-R fuel system are almost equally worn-out, and that with the appearance of the first sign of wear they all are dangerously close to the end of their working lifetime
That is why a C-R service package has been designed, with the aim to promote the approach of complete overhaul of the C-R fuel system, which in only one step or workshop visit, during which all key high-load and wear-exposed C-R fuel system components are replaced.
Thus, in addition to a quick repair, the owner of the vehicle also receives a two-year warranty for the repair if it is performed in a workshop authorized for that type of repair, and all C-R service package components are built-in during the repair procedure.
The installation of the C-R service package almost completely avoids sudden, extensive and very expensive repairs of the C-R fuel system, significantly improving the performance of the engine compared to the operation of the engine with a worn-out C-R fuel system, by primarily reducing consumption and harmful emissions, and increasing the power and reliability of the engine.