d. Clean and Inspect. Clean blower wheel, stator
and rotor with clean dry cloth. Inspect stator and
rotor for signs of friction wear. Check stator wires
for breaks, looseness and good insulation.
(1) Rotor. The rotor is a permanent magnet as-
sembly and should not deteriorate.
(2) Stator. Using an ohmmeter, check the stator
for open circuitry. High pot test the stator to ground
for short circuits at 1070 volts.
(1) Stator. Attach stator (15) to engine using
screws (12) and lockwashers (13). Replace wire clamp
to oil filter casting. Reconnect stator leads (14) at
(2) Rotor. Install rotor (11) into blower wheel (4)
using screws (9) and lockwashers (10). Install blower
wheel per paragraph 7-7. Install blower housing per
Operator and Organizational Maintenance Manual.
Section III. ENGINE INTERNAL ASSEMBLIES
7-8.1. ENGINE COMPRESSION TEST.
The engine cylinder compression tests of this
paragraph may be used to determine the condition of
engine valves, pistons, piston rings, and cylinders.
Normal cylinder pressure should be between 350 to 450
psi, depending upon engine condition. Corrective
maintenance should be considered if cylinder pressure
is below 325 psi or if there is a pressure difference of 15
percent or more between cylidners. These pressure
ratings apply to a warm engine at cranking speed (ap-
proximately 300 rpm).
a. Compression Test.
(1) Run the engine until normal operating
temperature is reached.
(2) Stop engine and remove all injector nozzle
assemblies in accordance with paragraph 7-20a.
(3) Disconnect end tag wires to governor fuel shut
off solenoid (K5).
(4) Obtain or fabricate two compressing adapter
mounting studs (see table 2-2).
(5) Install two compression adapter mounting
studs (3, figure 7-8.1) into cylinder head (13) in place of
screws (1, figure 7-45).
(6) Assemble gasket (7, figure 7-8.1), adapter (8),
gasket (9), heat shield (10) and gasket (11) on compres-
sion adapter (6) (see table 2-l).
(7) Install compression adapter and assembled
parts into cylinder head opening (12) of cylinder head
(8) Install retainer flange (5) over compression
adapter studs (3), secure compression adapter (6) to
cylinder head (13) with two MS51967-2 nuts (2) (from
bench stock) and washers (4).
(9) Connect compression tester gage (1) (see table
2-1) to compression adapter (6).
(10) Crank the engine. Read and record cylinder
pressure as indicated by the compression tester gage.
(11) Remove nuts (2) from studs (3). Disassemble
and remove items 4 through 11 from cylinder head (13).
Diesel engines have very close clearances.
Too much oil squirted into the cylinder may
cause a hydrostatic lock and damage the
piston when the engine is cranked with com-
pression adapter and tester gage installed.
(12) Squirt a small amount of oil (approximately 30
drops) into the cylinder through the cylinder injector
(13) Assemble and reinstall items removed in step
(14) Crank the engine. Read and record cylinder
pressure. If the cylinder pressure has increased con-
siderably from the pressure recorded in step (10)
above, the rings and cylinder bore should be checked
for correct tolerances and wear limits.
(15) If the cylinder pressure has increased only
slightly, the mating surfaces of the valves should be
checked for abnormal conditions.
(16) Repeat steps 5 through 15 for each cylinder.
(17) Install injector assemblies in accordance with
(18) Reconnect wires to governor fuel shut off
Change 3 7 - 9