Filter

Fitted between the reservoir and the pump, or ahead of the distributor, the filter strains out dirt, metal particles and other debris carried in the oil or grease before it reaches the smaller passages downstream. Volumetric and progressive distributors meter lubricant through fine internal orifices and piston bores, and a stray particle is enough to jam one of these and starve a lubrication point without any obvious sign at the pump.

The filter element should be checked and cleaned or replaced at routine service intervals, particularly where the lubricant is topped up from open containers or the equipment runs in a dusty environment. It is a low-cost way to protect the more precise components of the system and avoid an unplanned strip-down of a blocked distributor.