By Eric Brisbon
The number one enemy of any fuel injection system is contamination, plain and simple. Whether it’s a modern-day rail system with operating pressures of 2-3000 Bar or a legacy pump running at 600 Bar, the introduction of foreign particles or substances can cause significant durability issues and shorten the overall life of your equipment.
Consider the fact that many fuel systems have metal to metal sealing surfaces. Non-gasketed surfaces capable of sealing injection pressure require very flat, very smooth and very clean surfaces. The slightest variation in contact stress caused by foreign particles can cause leak. A riskier concern is that the leak may not show up right away. Costs to repair a leaking fuel system after installation can be excessive and create engine conditions that are very unfavorable to the user.
Similarly, sliding surfaces which are used extensively in pumping elements and normally fit to few micron, seal strictly on the merit of their diametral fit and surface condition of the mating parts. When you consider a strand of human hair is 50-100 micron in diameter or a spec of dust runs 5-10 micron, it becomes easy to imagine that even the slightest levels of contamination can cause very big problems.
Normally OEM manufacturers use clean room environments with temperature and humidity control while sizing and matching components of fuel injection high pressure products. Operators wear gloves, coats and head gear to ensure no foreign material is being introduced during the assembly process. The room air is filtered, and shoe scrubbers are usually encountered when entering the room to ensure very clean, almost sterile assembly areas to ensure the highest level of cleanliness. They understand the importance of keeping things clean to a very high standard.
Caution must also be used during servicing of fuel systems, as many shops are not equipped with this type of sophisticated equipment. If you are experiencing short term failures, engine performance concerns, or inconsistent reliability, always start with examining cleanliness first. Poor assembly and handling practices, lack of preventative maintenance for filters, hoses and transfer equipment, or a lackadaisical attitude about keeping your work areas clean can lead to unpleasant issues with your customers. There is no substitute for a well-kept, hygienic shop.
Consequently, an ounce of prevention can result in pounds of cure with sound cleanliness practices and consistency within your processes. Keeping it clean is by far the most important attribute to have to achieve a durable and reliable diesel fuel system regardless of make, model, age or size.