15.1 Preventive Maintenance
DETROIT DIESEL 53
after 1/2 hour or 15 miles and again after 8 hours or 240
miles of operation. Thereafter, check the tension of the
drive belts every 200 hours or 6,000 miles 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
of similar size should not be used as a substitute for a
matched belt set; premature belt wear can result
because of belt length variation. All belts in a matched
set are within .032 " of their specified center distances.
NOTE: When installing or adjusting
an accessory drive belt, be sure the
bolt at the accessory adjusting pivot
point is properly tightened, as well
as the bolt in the adjusting slot.
Adjust the belt tension so that a firm push with the
thumb, at a point midway between the two pulleys, will
depress the belt 1/2 " to 3/4 ". If a belt tension gage
such as BT-33-73F or equivalent is available, adjust the
belt tension as outlined in the Table.
To clean either the hair or polyurethane type air
BELT TENSION CHART (Ibs/belt)
compressor air strainer element, saturate and squeeze it
in fuel oil, or any other cleaning agent that would not be
detrimental to the element, until dirt free. Then dip it in
lubricating oil and squeeze it dry before placing it back
At a major engine overhaul, discard the bearings in the
in the air strainer.
fan hub assembly used in radiator-cooled engines.
Pack the hub assembly, using new bearings, with
For replacement of the air strainer element, contact the
Chevron BRB No.
2 grease or an equivalent
nearest Bendix Westinghouse dealer; replace with the
polyurethane element, if available.
1972 General Motors Corp.