PS Magazine - TB 43-PS-570
PS, The Preventative Maintenance Monthly
ISSUE 570
MAY 2000
PS 570
7
PS 570
6
MAY 00
HEMTT . . .
To prevent as much slobbering as
possible, limit idling to 10 minutes or
less, especially when the humidity is
high and the outside temperature is low.
Under those conditions, a diesel en-
gine doesn’t stay hot enough to com-
pletely burn the fuel. The unburned
HEMTTs are the workhorses of haul-
ing, and to keep any “horse” ready to
work you’ve got to take care of it.
That takes all the know-how you can
gain from PMCS items in TM 9-2320-
279-10, plus these tips:
Limit Idling
HEMTT engines are known
“slobberers” when they’re idled too
long. Unburned fuel condenses in the
air box and drips from the drain hose,
making a mess that looks like an oil
leak.
Before you write up diesel slobber
as an oil leak, warm up the engine.
Run it at high idle—between 1,000 and
1,200 rpm—for 5–10 minutes. Watch
the temperature gauge. When the gauge
needle is in the normal range, run the
engine another couple of minutes. Then
Check hose for leaks
Squeeze dust cap
stuff eventually gets into the crankcase,
diluting the oil and causing extra wear
and tear on engine parts.
Prevent as much of this damage as
possible by shutting down if you’ll be
sitting still for longer than 10 minutes.
Engine Leaks
The HEMTT engine is a known
leaker, too, losing oil from the front
seal. But not every Class III leak makes
your truck immediately NMC. Report
the leak, but keep an eye on it. There
are 7
1
/
2
gallons of oil in the engine, so
a little loss while you complete your
mission or scheduled repairs is OK.
Once the mission is complete and
scheduled repairs finished, then the
truck is NMC for the Class III leak.
Even with no leaks, the engine uses
a lot of oil. A good rule of thumb is
that if you add less than 20 percent of
the oil—6 or 7 quarts—between sched-
look at the air box drain hose. If it’s
just slobber, the wetness will be gone.
uled services, it’s still OK to run the
truck. Use more than that and the en-
gine needs repair.
Clean Air
Before operation, squeeze the dirt out
of the dust cap on the bottom of
the air cleaner. Do it more often if
you’re operating in a dusty or sandy
area.
don't
horse
around
with hemtt
pm! these tips will
keep it
ridin' tall
in the
saddle
!
makes
sense to
me!
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