TM 5-4320-218-15
Section XIII. CYLINDER BLOCKS AND CRANKCASE
122. Cylinder Block Installation
119. Description
a. Position a new gasket (23, fig, 30) over
a. Crankcase. The crankcase is a one-piece
the studs of the crankcase. Install the appropri-
casting machined at the top and fitted with
ate cylinder block (7) and secure it with the
studs to mount the two cylinder blocks. The,
six lockwashers (18) and nuts (17). Tighten
camshaft bores are honed, and serve as bearing
the nuts to 62-78 foot-pounds torque.
surfaces for the camshaft.
b. Install the pistons and connecting rods
b. Cylinder blocks. The cylinder blocks are
cast in pairs and are provided with cooling fins.
c. Install the valves (par. 102v).
The valve-stem guide bores are machined in
each of the blocks.
123. Crankcase Disassembly
a. Remove the timing gears (par. 106b).
120. Cylinder Block Removal
b. Remove the crankshaft (par. 116a).
a. Remove the valves (par. 102c).
c. Remove the camshaft (par. 116b).
b. Remove the connecting rods and pistons
d. Remove the cylinder blocks (par. 120).
e. To remove a defective oil filler tube (2,
c. Remove the six nuts (17, fig. 30) and
fig. 28), crush the tube and withdraw it from
lockwashers (18) that secure each cylinder
the crankcase.
block (7) to the crankcase; remove the cylin-
124. Crankcase Cleaning and Inspection
der blocks and gaskets (23). Tag them so that
they will be reinstalled on the same side of the
a. Steam the crankcase, or wash it with a
crankcase from which they were removed.
wire brush and an approved cleaning solvent to
remove all rust and scale; dry thoroughly.
121. Cylinder Block Cleaning and
b. Examine the oil filler tube for corrosion,
Inspection
bends, or dents. Repair or replace the oil fill-
er tube as necessary.
a. Clean, inspect, and repair the cylinder
c. Examine the camshaft bores. Replace a de-
bores as necessary.
fective crankcase.
b. Clean, inspect, and repair the valve seats
d. Examine the entire crankcase for cracks
and bores as necessary.
or breaks. Replace a defective crankcase,
c. Use a wire brush, compressed air, and
an approved cleaning solvent to clean the cool-
125. Crankcase Reassembly
ing fins of the blocks. Inspect the cylinder
a. If the oil filler tube was removed, chill a
blocks for cracks, breaks, or damaged cooling
new one with dry ice, and install it in the crank-
fins. Replace a defective cylinder block.
case.
d. Inspect the manifold mounting studs, cyl-
b. Install the camshaft (par. 118).
inderblock mounting studs, and mounting hard-
c. Install the crankshaft (par. 118).
ware. Tighten any loose mounting studs; re-
d. Install the timing gears (par. 108).
place any defective hardware.
e. Install the cylinder blocks (par. 122).
e. Examine the threaded cylinder-head
f. Lubricate the entire pump unit according
mounting holes. Repair any holes that have
to the lubrication guide (fig. 8).
bad threads.
g. Start the unit and check for signs of un-
usual operation.
f. Replace the cylinder-block gaskets.
Section XIV. CHECK VALVE
126. Description
factory to close automatically when the pump is
The check valve (fig. 34) is a lever-operated
shut down or can be adjusted to remain open.
discharge valve. This valve is adjusted at the
The adjustment of the valve is made by the