TM 5-3895-346-14
OIL FILTERS
ENGINE OVERHAUL
LUBRICATING OIL FILTERS
Series 53 engines are equipped with a full-flow type lubricating oil filter. A bypass-type oil filter may be used in
addition to the full-flow type filter when additional filtration is desired.
Full-Flow Oil Filter
The full-flow type lubricating oil filter (Fig. 1) is installed ahead of the oil cooler in the lubrication system. On
the four-cylinder models, the oil filter may be mounted with the filter shell up, down, or toward the rear, except
when on the blower side of the engine where the down and rearward positions are optional.
The filter assembly consists of a replaceable element enclosed within a shell which is mounted on an adaptor
or base. When the filter shell is in place, the element is restrained from movement by a coil spring.
All of the oil supplied to the engine by the oil pump passes through the filter before reaching the various moving
parts of the engine. The oil is forced by pump pressure through a passage in the filter base to the space
surrounding the filter element. Impurities are filtered out as the oil is forced through the element to a central
passage surrounding the center stud, out through another passage in the filter base, and then to the oil cooler.
Figure 1. Proper Installation of Flexible Oil Filter Hoses
A valve, which opens at approximately 18-21 psi (124-145 kPa) is located in the filter base on engine-mounted
filters or in the hose adaptor (7/8-inch hoses) with a remote mounted filter and will bypass the oil directly to the
oil cooler should the filter become clogged.
Oil Filter Maintenance
With the use of detergent lubricating oils, the color of the lubricant has lost value as an indicator of oil
cleanliness or proper filter action. Due to the ability of the detergent compounds to hold minute carbon
particles in suspension, heavy-duty oils will always appear dark colored on the oil level dipstick.
Heavy sludge deposits found on the filter elements at the time of an oil change must be taken as an indication
that the detergency of the oil has been exhausted. When this occurs, the oil drain interval should be shortened.
The removal of abrasive dust, metal particles, and carbon must be ensured by replacement of the oil filter
elements at the time the engine oil is changed.
Selection of a reliable oil supplier, strict observation of his oil change period recommendations, and proper filter
maintenance will ensure trouble-free lubrication and longer engine life.
316
