cylinder wear (the difference between these two
Clean the oil and water passages in the block with
measurements) is 0. 008 inch.
compressed air. Remove varnish deposits with a wire
brush.
(4) Replace the block if it is cracked or defects
cannot be repaired. Replace loose or damaged
c. Inspection.
studs. Retap damaged threads. If a proper
(1) Inspect the block for cracks, amaged
d
piston fit cannot be attained (para 119c(1)), the
sealing surfaces, scored or damaged
cylinders are scratched or scored, or cylinder
bearing seats, scored or scratched
wear exceeds 0. 008 inch, rebore the cylinders
cylinder walls, damaged threads, loose or
as directed in d below.
damaged studs, corrosion in the water
jacket, or other defects.
d. Reboring Rebore the cylinders to 4. 020to 4. 022-
.
(2) Check piston fit in the cylinder bores (para
inch diameter (0. 020 in. oversize). If this is not
119c(1)).
sufficient to eliminate cylinder wear or damage, rebore
(3) Check cylinder bore wear with an inside
the cylinders to 4. 040to 4. 042-inch diameter (0. 040
micrometer. Measure the cylinder bore at
inch oversize). Maximum allowable overbore is 0. 040
450 intervals below the travel of the
inch.
lowest piston ring where the cylinder is not
worn. Compare this measurement with a
e. Assembly and Installation.
measurement taken about Y inch below
the top of the cylinder. The maximum
allowable
(2) Install the engine (para 114c).
Section VII. PUMP REPAIR
(2) Clean the check valve parts with soapy
123. General
water; rinse and wipe dry.
(3) Inspect the weight and check valve parts for
a. The pump is a centrifugal type with a 6-inch intake
wear, rips, elongated holes, stretching, and
and a 6-inch discharge. It is self-priming and has an
other damage. Replace damaged parts.
integral check valve which retains the fluid in the volute
(4) Inspect the gaskets (3, 11, 13, and 17) for
when the pump is shut down. The enlarged top of the
damage; replace if damaged.
volute helps to provide rapid self-priming when the pump is
(5) Inspect all other parts for wear, cracks,
started.
breaks, stripped threads, or other damage;
b. The drive shaft is mounted in ball bearings
replace damaged parts.
supported in the bearing frame. One single row ball
c. Assembly and Installation
.
Assembly and
bearing and one double row ball bearings are used. The
impeller is mounted on the end of the shaft opposite theinstallation of the suction head and check valve are the
drive end with the ball bearings supporting the centerreverse of removal and disassembly.
section of the shaft.
c. A mechanical seal is provided to prevent theufd 126. Discharge Elbow and Lifting Bail
l i
being pumped from entering the bearing frame.
a. Removal. Remove the discharge elbow and lifting
bail in order of index numbers 20 through 25 assigned to
124. Pump
a. Removal. Remove the pump from the pumping
b. Cleaning and Inspection.
unit (para 101a).
(1) Clean all parts in an approved cleaning
b. Installation. Install the pump (para 101a).
solvent; dry with clean, dry, compressed air.
(2) Inspect all parts for wear, cracks, breaks,
125. Suction Head and Check Valve
stripped threads, or other damage; replace
damaged parts.
a. Removal and Disassembly
.
Remove and
c. Installation Installation of the discharge elbow
.
disassemble the suction head and check valve in order of
and lifting bail is the reverse of removal.
index numbers 1 through 19 assigned to figure 74.
b. Cleaning and Inspection.
(1) Clean all metal parts in an approved cleaning
solvent; dry with clean, dry, compressed air.
85