TM 5-4310-349-14
(3) Measure the clearance of the piston pin
5-4.1 Pistons, Piston Rings, Connecting Rods,
bushing.
Check for proper fit.
Aline or replace
and Cylinder Block (Model HR10-8M4)
connecting rods if necessary.
a. Removal and Disassembly.
(4) Place the piston rings in the cylinder bore
(1) Remove the compressor assembly.
with the piston ring square in the cylinder bore about 1/2
(2) Refer to figure 5-1 and disassemble tubes,
inch from the top.
manifolds, and air cleaner as shown.
(5) If the ring gap is less than the specified
(3) Refer to figure 5-2 and disassemble intake
width, file across butt ends of the rings to increase the
and exhaust valves as shown.
gap to the required tolerance. If the ring gap is greater
(4) Refer to figure 5-1 and remove cylinder
than required, replace the entire set of rings.
assembly.
(6) Measure the ring groove in the piston for
(5) Access to connecting rod attachment bolt is
wear. Replace piston if necessary.
reached from above. Refer to figure 5-3.1 and remove
c. Reassembly and Installation.
connecting rod bolts and withdraw connecting rod cap,
(1) Refer to figures 5-1, 5-2, and 5-3.1 and
connecting rod and piston assembly from top of
reassemble and install the pistons, piston rings,
crankcase.
connecting rods, and cylinder block, taking the following
CAUTION
precautions:
Mark the connecting rod from which
(a) If new connecting rod bushings are
the caps were removed, and
to be installed and are not prefitted, ream the bushings.
reassemble caps on the same rod.
(b) When installing piston rings expand
Do not intermix the connecting rods
them carefully and sufficiently to allow the ring to slide
and caps.
freely over the piston to the proper position. Starting
with the bottom ring, install piston rings in their proper
grooves. Stagger ring gaps so that they are not lined
(6) Disassemble connecting rods, pistons and
up.
rings as shown in figure 5-3.1.
(c)
Lubricate
each
piston
and
connecting rod assembly with a light coat of engine oil
NOTE
before installing. Install the connecting rod and piston
Mark connecting rod and piston to
assembly from the top of the crankcase. Positioning of
assure
correct
relationship
at
the connecting rod bearing surface to the crankshaft is
reassembly.
accomplished from the top of the crankcase by reaching
down along side connecting rod to install lower
connecting rod cap as shown in figure 5-3.1.
NOTE
(d) Install connecting rod bolts, from the
Do not remove the connecting rod
top, and torque to 25 ft. lbs. torque.
bushings unless inspection reveals
(e) When installing cylinder block,
them defective.
compress the piston rings carefully. Always use new
flange gasket and torque capscrews to 45 ft.-lbs. torque.
b. Cleaning, Inspection and Repair.
(f) When reassembling intake and
(1) Clean all parts with cleaning solvent and dry
exhaust valves be sure to seat large diameter of the
thoroughly.
spring in the cage of all valves.
(2) Inspect the cylinder block for broken cooling
fins and cracks. Inspect the cylinder bore for wear,
scoring, pitting, or other damage. Replace the block if
defective.
Change 2 5-4.1/(5-4.2 blank)
