Contaminated fluid systems can lead to shortened component and fluid life, reduced productivity, and even catastrophic failure.

by Carmen L. Rose

Controlling contamination in oils and diesel fuel has grown in importance as aggregates operations work to increase productivity with machines that deliver more power, greater breakout forces, and faster cycle times. To meet those requirements, most machines use electro-hydraulics, higher-system pressures, and tighter clearances. As a result, modern fluid systems — hydraulics, transmissions/final drives, fuel systems, and engines — are more sensitive to contamination.

Keeping the shop clean helps keep dirt out of components during repairs.

Good contamination control

Contaminated fluid systems can lead to shortened component and fluid life, reduced productivity, and even catastrophic failure as well as the resulting costly downtime associated with unscheduled repairs. Tests prove that clean oil and fuel extends machine life and maintains machine productivity.

Instituting good contamination control procedures has proven to have positive effects for all organizations that have engaged the program.

The concepts of contamination control are simple; the real work is in the detail. Categorizing the sources of contamination lends perspective. Contamination can be built in at the factory; contained in new fluids; introduced through worn seals, pitted rods, vent ports, and incorrect maintenance practices; and generated in the machine system.

The steps that aggregate operations can take to control contamination range from the straightforward, such as good housekeeping, to the uncommon, such as particle counting. The basic procedures focus on clean facilities, clean components, clean processes, and clean fluids.

Housekeeping encompasses all that it takes to keep maintenance facilities and service vehicles clean. A clean shop means there is less dirt, dust, and grit to get into components or to be transferred into components. Cleaning floors frequently, cleaning up spills immediately, keeping workbenches free of debris, and limiting use of the floor for storage all contribute to keeping machine systems clean. Use absorbent mats to soak up fluids spills rather than using absorbent particles, which create airborne dust. Washing heavy equipment and large components thoroughly before they enter the shop helps keep dirt out.

Storing parts in their original packaging and with caps on hoses keeps dirt out.

Proper parts handling and storage goes hand in hand with good housekeeping practices. Keep components packaged until they are ready to install, and store them in clean, dry areas. Return parts to storage in their packaging. Protect components in the assembly/maintenance area, and clean components properly before assembly.

Hoses, fluids, and filters

Hydraulic hose assembly and storage require special attention. Hoses and tubes should be cleaned and capped. The hose assembly process creates contaminants. As a result, it’s recommended to clean the inside of each hose assembly with a hose cleaner, which pneumatically fires a cleaning projectile.

Covering work in progress keeps dirt out. Absorbent pads don’t generate dust as some oil absorbing products do.

Oil storage and transfer processes can introduce contaminants. Both oil and diesel fuel storage tanks should be equipped with desiccant breathers to keep dirt and water out. Barrel covers should be used to keep dirt and water from entering around the bung. Even new oil can contain thousands of microscopic particles, and oil picks up contaminants if it is stored in dirty drums or bulk tanks or transferred through dirty lines. Filter oil before it fills a machine by using a transfer filter cart. Fuel, too, should be filtered before it fills a machine’s tank. And when machines are serviced, using a filtration cart to remove contaminants from fluids has been shown to extend component life.

Remove parts from packaging just before assembly.