To remove contaminants from a new hose assembly, Caterpillar recommends shooting a foam projectile through the hose and couplings using forced air. “This procedure is done twice, once in each direction though the hose assembly,” says Gruber. “After cleaning a hose assembly in this manner, the ends should be capped and plugged to further protect the assemblies from contaminants during transport and storage.”
There are other ways to clean a hose, as well. “Cleaning methods vary based on shop capabilities, the cleanliness level required and the critical nature of the application,” says Skovrinski. “For hose going to a pumping component, cleanliness is absolutely critical; for hose going to a tank or filter, cleanliness is less critical.”
Three different methods are used to clean hydraulic hose assemblies with varying levels of cleanliness: shop air blow, pellet gun (projectile or ‘cleaning pig’) or fluid flush. “The easiest and most commonly used cleaning method is to blow shop air through the hose assembly after the hose has been rough cut to the desired length,” says Skovrinski. “However, a shop air blow offers minimal cleaning and is the least effective method.”
A better method is to use a pellet, which is shot through the hose with compressed air. “The pellet breaks up the debris and cuttings that accumulate up to 6 in. back from the hose openings after the hose has been cut, and flushes them out of the hose,” says Skovrinski.
“A fluid flushing apparatus provides the most effective cleaning method,” reports Skovrinski. “With this technique, cleaning fluid is flushed at a high velocity through the hose until the hose meets the strictest cleanliness levels. After cleaning, cap the assembly on both ends to prevent debris from entering until the hose is installed.”
Through daily inspections, a proactive preventive maintenance program, proper selection and a concerted effort to maintain cleanliness, you can eliminate much of the downtime due to hydraulic hose failure.