Chevrolet 70 1969 Series, Shop Manual

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ENGINE C O O LIN G SYSTEM 6K-9
Figure 7—Testing Belt Tension with Dial Gauge
FAN A N D DRIVE BELTS
D R IV E B E L T T EN SIO N A D J U S T M E N T
Drive belts must be kept at proper tension. A
loose or broken drive belt will affect operation of
driven accessory. A drive belt that is too tight will
place excessive stress on bearings within acces­
sory.
Belt tension adjustments should be made with
an accurate belt tension dial gauge. Tension
readings are taken as shown in figure 7.
Fan and generator drive belts for all models
are adjusted to 120 to 130 pounds tension for new
belts and 80 to 90 pounds tension for used belts.
New belts are adjusted to a higher tension to allow
for stretch in the belt. As stretch occurs, tension
should decrease to 80 to 90 pounds.
C A U T IO N : On models with 6V-53 engine, be
sure fan blade does not contact shroud after ad­
justment of drive belt tension. Shroud can be ad­
justed to obtain sufficient clearance between fan
blade and fan shroud.
N O T E : On a new vehicle or after having in­
stalled new belts, check tension of belts twice in
first 200 miles of operation.
When making adjustment, examine belts. R e ­
place if frayed or worn.
D R IV E B E L T R E P L A C E M E N T
On some vehicles, several accessories may
be driven from multiple groove crankshaft pulley,
and the replacement of any one inside drive belt
will make it necessary to remove all the outside
belts first.
N O T E : Instructions for replacing power steer­
ing drive belt are given in "P O W E R S T E E R IN G "
(SEC. 9B). Refer to "A IR C O M P R E S S O R A N D
G O V E R N O R " (SEC.6T) for adjustment and replace­
ment instructions for air compressor drive belts.
IMPORTANT
When replacing dual or triple drive
belts, it is essential that entire set be
replaced at same time. Belts are avail­
able in matched sets only.
All Except 5V-53 Diesel Engines
The following procedure applies to replace­
ment of water pump and generator drive belts on
tilt cab models and fan, water pump and generator
drive belts on conventional cab models.
1. Remove the air compressor drive belt (if
equipped).
2. Loosen bolt at generator adjusting arm and
loosen two pivot bolts at generator support bracket.
3. Move generator toward engine until belts
can be removed from pulley.
4. To install new belts, position belts on pull­
eys and move accessory away from engine until a
tension of 120 to 130 pounds is measured.
5. Tighten accessory adjusting arm bolt and
pivot bolts.
6. Install air compressor drive belt (if equip­
ped).
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L