SECTION 12
TIRE INFLATlON SYSTEM
reaches the high pressure setting of the
governor, the governor opens, allowing air to
pass from the reservoir through the governor
and into the cavity beneath the unloader
pistons. This lifts the unloader pistons and
plungers. The plungers move up and hold the
inlet valves off their seats.
12-17. With the inlet valves held off their seats
by the, unloader pistons and plungers, air is
merely pumped back and forth between the two
cylinders. When air is used from the reservoir
and the pressure drops to low pressure setting
of the governor, the governor closes and In
doing so exhausts the air from beneath the
unloader pistons. The unloader saddle spring
forces the saddle, pistons and plungers down
and the inlet valves return to their seats.
FIGURE 12-3.
Compression is then resumed.
12-18. LUBRICATION.
12-19. Oil from the engine is forced through the
oil passage in the crankshaft and out around
each connecting rod journal. The turning
motion of the crankshaft throws the oil, which
is forced out at the journals, against the
cylinder bores and crankcase walls, lubricating
the bores and crankshaft bearings.
12-20. The die cast aluminum connecting rods
are drilled at the top of the rods. The wrist
p i n s and bushings are lubricated by oil
dripping from the drip-boss on the piston into
a catch funnel at the top of the rod and
through the drilled passage to the bushings
and pins.
FIGURE 12-4.
12-21.
REMOVAL.
a. Drain the air system.
b. Drain the engine coolant, compressor
block and cylinder head.
c. Disconnect ail hoses from the compressor
and cap all openings.
d. Remove the mounting capscrews. Remove
t h e bolt from the pulley and lift out the
compressor.
12-22. PREPARATION
FOR DISASSEMBLY.
a. Clean compressor exterior of road dirt and
grease, using a good cleaning solvent.
b. Before complete disassembly, mark the
FIGURE 12-5.
following items to show their relationship:
12-3.
