SECTION IV
PREVENTIVE MAINTENANCE
A method of determining when the elements are plugged
4. Before discarding the filter elements, inspect the
to the extent that they should be changed is based on
foreign material trapped in them. The type of material
the fuel pressure at the cylinder head fuel inlet manifold
trapped in the filter elements could give an indication of
and the inlet restriction at the fuel pump. In a clean
deterioration of some hydraulic system component.
system, the maximum pump inlet restriction must not
exceed 6 inches (152.4 mm) of mercury. At normal
5. Clean the shell thoroughly in a suitable solvent.
operating speeds (1800-2800 rpm) the fuel pressure is
45 to 70 psi (3.1-4.8 bars). Change the fuel filters
6. Install a new gasket in the filter head. Install the new
whenever the inlet restriction (suction) at the fuel pump
filter element in the shell, position the shell under the
reaches 12 inches (304.8 mm) of mercury at normal
filter head, and tighten the center bolt to 30-35 FT-LBS.
operating speed and whenever the fuel pressure at the
(4.15-4.8 m-kg). Run the engine, with the pump drive
inlet manifold drops to 45 psi (3.1 bars).
engaged, several minutes and check for leakage.
To replace the fuel filters, proceed as follows (see Figure
4-9): 1. Unscrew the fuel filters and discard them.
2. Fill the new filters with clean fuel.
3. Install the fuel filter. Tighten them by hand until the
seal touches the filter head. Then tighten each filter an
additional one-half to three-fourths turn.
Figure 4-10. Hydraulic Oil Filters
CHECK ENGINE BELTS
New drive belts will stretch after the first few hours of
operation. Retighten the fan drive, water pump drive,
and alternator drive belts after the first 8 hours or 240
miles of operation. Thereafter, check the tension of the
drive belts monthly and adjust if necessary. Too tight a
belt is destructive to the bearings of the driven part; a
loose belt will slip.
Replace all belts in a set when one is worn. Single belts
Figure 4-9. Engine Fuel Filters
of similar size should not be used as a substitute for a
CHANGE HYDRAULIC OIL FILTERS
matched set, premature belt wear can result because of
The hydraulic system oil is filtered on the return side by
belt length variation. All belts in a matched set are within
two full flow type filters located at the right rear corner of
.032" (8.1 mm) of their specified center distances.
the engine compartment.
Adjust the belt tension so that a firm push with the
To change the hydraulic oil filter, proceed as follows (see
thumb, at a point midway between two pulleys, will
Figure 4-10): 1. Remove the cover above the filters.
depress the belt 1/2" to 3/4" (12.7-19.0 mm).
The cover is held in place by Zeus fasteners.
CHECK BRAKE ADJUSTMENT
2.. Remove the center bolt and washer from the bottom
The wheel brakes should be checked, at a monthly
of the filter.
interval, to determine the need for adjustment. The rear
brakes should be adjusted when the stroke needed to
3. Remove the shell and gasket from the filter head.
apply the brakes reaches 2-1/4" (57 mm).
1-4-10
