TM-9-2320-272-24-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 1 OF 4
JUNE 1998
TM-9-2320-272-24-1 - Page 116 of 1015
TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM
INTERVAL
CHECK/
TO
SERVICE
PROCEDURE
NOT FULLY
MISSION
CAPABLE IF:
25
Semi-
Compres-
a.
Check compressor for security of mounting and leaks.
annual
sor
l. If M939/A1 series engine-mounted compressor is
loose, notify DS maintenance.
2. If M939A2 series engine-mounted compressor is
loose, replace locknut and tighten to 55 lb-ft (77 N•m).
b.
Check condition and security of cooling lines to air
compressor. Tighten cooling lines, if loose. Replace cooling
lines if split, cracked, or damaged in such a manner as
to cause leaks (para. 3-55).
c.
On M939A2 series engines, check condition of
compressor oil line and fittings. Tighten fittings and oil
line if loose. Replace oil line if split, cracked, worn, or
damaged in such a manner as to cause leaks (para. 3-206).
d.
Check condition and security of input tube and hoses,
output air line, and governor control air line. Tighten
output and governor control air lines, if loose. Replace
input tube or hoses if split, cracked, collapsed, distorted,
or damaged in such a manner as to prevent a tight seal or
restrict incoming air (para. 3-55).
26
Semi-
Engine
a.
Inspect all engine oil lines, hoses, and fittings for
annual
lubrication
loose connections, cracks, frays, wear, and damage
system and that could cause leaks. Tighten loose connections, and
oil lines
replace any oil lines, hoses, and fittings that are cracked,
frayed, worn, or damaged and could cause leaks.
NOTE
• Oil filter is located on lower front left side of
engine on M939/A1 series vehicles and lower front
right side of engine on M939A2 series vehicles.
• M939/A1 series vehicles utilize an element-type
engine oil filter, while M939A2 series vehicles use
one of two styles of cartridge-type engine oil
filters.
b.
Inspect M939/A1 series vehicles for security of oil
filter housing. Ensure filter center bolt is tight. If center
bolt is loose, tighten 25-35 lb-ft (34-48 N•m).
c.
Inspect M939A2 series vehicles for security of oil
filter head. Ensure spin-on oil filter is tight. If spin-on oil
filter is loose, hand-tighten, then tighten an additional
3/4 turn with a wrench.
d.
Check engine oil and dipstick for metal particles.
Notify DS maintenance if metal particles are found.
2-28
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