Chevrolet 70 1969 Series, Руководство по ремонту

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POWER BRAKE 5-44
AIR COMPRESSOR AND GOVERNOR
(BENDIX-W ESTMGHOIISE TU-FLO TYPE)
INDEX
Subject Page No.
Subject Page No.
Description and O peration of C om pressor . . ...............5-44 Assembly of C o m p re s s o r............................... .......................5-52
Troubleshootinsz C h a r t ............................................ ...............5-44 Air C om pressor G o v e rn o r............................ .......................5-57
Disassembly of C o m p re s s o r................................. ............... 5-46 C om pressor Tests After O v e rh a u l.......................................5-60
Cleaning. Inspection, and R e p a ir ....................... .............5-49 S pecificatio ns...................................................... .......................5-60
DESCRIPTION AND OPERATION OF COMPRESSOR
The com pressors covered in this m anual are single-
acting, two cylinder reciprocating type (fig. 1). The rated
capacity of com pressor is its piston displacem ent in cubic
feet per m inute when operating at 1250 rpm. C om pressors
can be readily identified by referring to nam e plate at­
tached to cylinder block. Plate will indicate either type
400 or 500. C apacity of T U -F L .0 400 is 7 - 1/4 cubic-feet
per m inute. C apacity of T U -F L O 500 is 12 cubic-feet per
minute. C om pressors are lubricated by the engine lubrica­
tion system.
Governor, acting in conjunction with the air com pressor
unloading m echanism , controls com pression of air as ex­
plained under “ Air C om pressor G overnor.” C onnecting
rod bearings are replaceable insert type. U pper ends of
connecting rods are equipped with replaceable bushings.
Piston pins are retained in pistons by wire-type locks.
On belt driven air compressors, the crankshaft is
m ounted in crankcase on a ball bearing in front and an
insert-type bearing in rear. O n gear-driven air com pres­
sors, crankshaft is m ounted on insert-type bearings (bush­
ings) both front and rear.
Figure 1 is typical of all com pressors covered herein
TROUBLESHOOTING CHART
This Troubleshooting C hart is to serve as a guide to fa­
cilitate an accurate diagnosis of a m alfunctioning air com-
pressor and governor.
COMPRESSOR FAILS TO MAINTAIN COMPRESSOR PASSES EXCESSIVE OIL
SUFFICIENT PRESSURE
Excessive wear.
Dirty intake strainer.
Dirty air strainer. (Im proper air strainer
Restriction in com pressor cylinder head intake
maintenance.)
or discharge cavities or in discharge line. High inlet vacuum .
L eaking or broken discharge valves. Small oil return line.
Excessive wear.
Excessive oil pressure.
Drive belt slipping.
Oil supply or return lines to com pressor
Inlet valves stuck open.
flooded.
W orn inlet valves.
Defective or worn oil seal rings in end cover.
Excessive system leakage or usage.
Piston rings not properly installed.
Back pressure from engine crankcase.
NOISY OPERATION
COMPRESSOR NOT UNLOADING
Loose drive pulley.
Defective unloader pistons or bores.
Restrictions in cylinder head or discharge line. Intake cavity restrictions.
W orn or burned out bearings. Defective governor.
C om pressor not getting proper lubrication.
U nloader line or cavity to governor restricted.
Excessive wear. U nloader m echanism binding or stuck.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP M A N U A L