TM 9-2350-256-20
CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
2-17 HYDRAULIC TROUBLESHOOTING-Continued
APU
SYMPTOMS
Engine fails to crank when
starting switch is operated.
Do steps A and B.
Engine cranks but fails to start.
Do steps C and G.
Engine hard to start.
Do steps D, E, F, H, and J.
Engine hard to start in cold
weather.
Do steps H, I, and J.
Engine starts but fails to keep
running, misfires, or lacks power.
Do steps H and K through M.
Engine overheating.
Do steps M and N.
Engine discharges black smoke.
Do steps I and Q.
Engine knocks.
Do step A.
Engine uses excessive oil and
discharges light blue smoky
exhaust.
Do step R.
A
B
C
D
E
F
G
H
I
Remove APU access cover (see paragraph 9-49).
heck for loose electrical connections. Clean and
tighten connections if loose.
Troubleshoot APU engine starter circuit (see
paragraph 2-19, APU starter circuit fails to operate).
Remove APU access cover (see paragraph 9-49).
Check vehicle tank and APU engine fuel supply line
for restrictions or damage. Clean fuel line or replace
if necessary (see paragraph 13-5).
Remove APU access cover (see paragraph 9-49).
Check fuel system for water. Bleed water at filters
(see paragraph 13-5).
Check for leaking APU fuel lines or fittings. Tighten
or replace defective lines or fittings.
Check for dirty fuel filters. Replace fuel filter
elements (see paragraph 13-5).
Remove access cover (see paragraph 9-49).
Troubleshoot fuel solenoid circuit (see paragraph
2-19, APU starter circuit fails to operate). If fuel
solenoid is defective, notify Direct Support
Maintenance.
Remove APU access cover (see paragraph 9-49).
Check for dirty air cleaner filter element. Clean or
replace filter element (see paragraph 13-2).
Check air preheater and glow plugs for malfunction
by troubleshooting APU starter circuit.
2-52
Change 1