SECTION 12
TIRE INFLATION SYSTEM
f. Slightly worn or scratched inlet valves can
piston and wrist pin and lock same by
be reclaimed by lapping them on a piece of
snapping short end into lockwire hole at the
fine crocus cloth on a flat surface, but it is
bottom of the piston.
suggested that new inlet valves be installed.
b. Install piston rings in correct location
12-32. REASSEMBLY.
with ring pipmarks up (figure 12-10). Stagger
the position of the ring gaps.
12-33. REASSEMBLY AND INSTALLATION
OF CYLINDER BLOCK.
c. Prelubricate piston, piston rings, wrist pin
and connecting rod bearings with clean engine
a. Position cylinder block gasket and block
oil before installing them in the compressor.
on crankcase according to markings made prior
to disassembly. Using capscrews with lock-
d. Remove connecting bolts and bearing cap
washers, secure cylinder block to crankcase.
from one connecting rod. Turn crankshaft so
one of its connecting rod journals is in the
b. If the crankshaft is fitted with oil seal
downward, center position and attach the
rings, install rings. Position ball bearings and
bearing cap to the connecting rod making sure
crankshaft in crankcase making sure the drive
end of the crankshaft is positioned as marked
before disassembly.
c. If one end of the crankcase is counter-
bored for holding a bearing, be sure the
crankshaft is installed through the correct end
of the crankcase.
d. Carefully press crankshaft and bearings
into crankcase using arbor press.
e. Position a new rear end cover gasket over
the rear end of the crankcase making sure the
oil hole in the gasket lines up with the oil hole
in the crankcase. Position and cover with oil
seal ring. If used, install over crankcase and
FIGURE 12-10.
end cover. The end cover should be positioned
the bolt lockwashers are properly positioned
correctly in relation to the oil holes in the
on the cap. Tighten connecting rod bolts
gasket and crankcase. Secure end cover to
evenly and bend the two (2) new lockwasher
crankcase with capscrews and lockwashers.
prongs up against the hex head of the bolt.
Install the other connecting rod and piston in
f. If your opposite end cover requires an oil
the same manner.
seal which was removed on disassembly, a
new seal should be pressed into end cover.
12-35. INSTALLATION AND REASSEMBLY
Position new end cover gasket and carefully
OF UNLOADER MECHANISM (see fig-
install end cover over crankshaft and to
ure 12-11).
crankcase. avoiding damage to the seal. Secure
end cover with capscrew and lockwashers.
a. The unloader pistons and their bores
must be lubricated prior to installation.lf new
12-34. REASSEMBLY AND INSTALLATION
unloader kits are being installed, the pistons in
OF PISTONS AND CONNECTING RODS
the kit are already lubricated.
a. If new wrist pin bushings are to be used,
b. Install the unloader pistons in their bores.
they should be pressed into the connecting
Do not cut the grommets or distort the back-up
rods so that the oil hole in the bushing lines
rings. Position unloader plungers in their
up with the one in the rod. The new bushings
guides and slip them in and over the tops of
should then be reamed or honed to provide
the,pistons.
between 0.0001 and 0.0006 inch (.00254mm -
.01524mm) clearance on the wrist pin. Position
c. Install the unloader spring seat in the
connecting rod in piston and press in wristpin
cylinder block; a small hole is drilled in the
so that lockwire hole in the pin aligns with that
block for this purpose. Position the saddle
of the piston. Install new lockwire through
12-8.
