Chevrolet 70 1969 Series, Руководство по ремонту

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AIR COMPRESSORS AND GOVERNORS 6T-2
LEFT SIDE M O U N T
1 Drive Pulley
2 Drive Belt
3 Air Line to Tank
4 Mounting Bracket
5 Swivel Bolt
6 Governor
7 Inlet Oil Line
8 Return Oil Line
RIGHT SIDE M O U N T
9 Governor to Tank Air Line
10 Mounting Base Bolts
11 Mounting Base
12 Intake Air Strainer
T-3012
Figure 2 — Air Compressors Installed
gine and gear driven (see fig. 1). All other com­
pressors covered here are driven by a belt from
the crankshaft pulley (see figs. 1 and 2).
The gear driven compressors are water-
cooled from the engine cooling system. The belt
driven compressors are either water-cooled or
cooled by air from the fan assembly.
All compressors are lubricated by oil from
the engine lubrication system.
Each compressor is equipped with a governor
assembly, which is attached to the cylinder head
or cylinder block by a bracket. This governor, in
conjunction with the air compressor unloading
mechanism, controls the compression of air.
COMPRESSOR MOUNTING AND DRIVE
(Refer to Figures 1 and 2)
On belt driven air compressors the mounting
and drive installations vary from one model to
another but all have the same basic principle of
attachment and adjustment. An adjusting arm
with a slot at one end) connects the air compres­
sor to the vehicle engine (generally at the engine
front cover). This arm is attached solidly to the
engine with a bolt or a bolt and nut. The slotted
end of arm is attached with a nut and bolt to an
adjusting arm bracket fastened to compressor.
The air compressor is mounted on a base
with four bolts or four bolts and nuts. This base
incorporates a lubricating oil return drain hole
and a boss which permits the use of one large
pivot bolt or two smaller pivot bolts as a method
of fastening the bottom of the air compressor.
This base also provides a pivot point for drive
belt tension adjustment. The pivot bolt and nut
secure the air compressor assembly to a support
bracket which is attached to the vehicle engine at
the cylinder block or lower front engine cover
(dependent on vehicle model).
The size, shape and relative arrangement of
the adjusting arm, the adjusting arm bracket, the
base and the support bracket are determined by
the requirements for each individual model.
All belt driven compressors are equipped
with a proper size pulley to produce the rpm
recommended by the manufacturer. When replac­
ing a pulley, it is of the utmost importance that
the correct one be used.
Some pulleys have a puller groove in the hub.
Use this groove when removing pulley to prevent
damage. Use extra care in removing a pulley
without the groove.
For belt tension adjustment, refer to
procedure under “ Drive Belt Maintenance and
Adjustment.”
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M A N U A L