DETROIT DIESEL 53
Preventive Maintenance
15.1
Item 19
There is no scheduled interval for performing an engine tune-up. As
long as the engine performance is satisfactory, no tune-up should be
needed. Minor adjustments in the valve and injector operating
mechanisms, governor, etc. should only be required
periodically to compensate for normal wear on parts.
Item 20
New standard V-belts will stretch after the first few hours of
operation. Run the engine for 15 seconds to seat the belts, then
retension them. Retighten new fan drive, pump drive, battery-
charging generator and other accessory drive belts 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 belt set are within .032" of their specified center
distances.
Adjust the belt tension so that a firm push with the thumb, at a point
Item 20
midway between the two pulleys, will depress the belt 1/2 " to 3/4" .
If belt tension gage BT-33-73FA or equivalent is available, adjust the belt tension as outlined in the Chart.
Fan Drive
Generator Drive
Two 3/8"
Engine
2 or 3 Single
or
One 1/2" One Wide
Model
Belts Belt
1/2" Belts
Belt
Belt*
2, 3, 4-53
40-50 -
40-50
50-70
40-50
6, 8V-53
60-80 80-100 40-50
50-70
40-50
All
For 3-point or triangular drive use a tension of 90-120.
'Belt tension is 50-70 for a single premium high capacity belt (.785" wide) used to drive a 12 cfm air compressor.;
BELT TENSION CHART (lbs/belt)
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.
Item 22
At a major engine overhaul, discard the bearings in the fan hub assembly used in radiator cooled engines.
Pack the hub assembly, using new bearings, with Texaco Premium RB or an equivalent performance
grease.
Item 23
Check the shut-down system every 300 operating hours or each month to be sure it will function when needed.
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