PS Magazine - TB 43-PS-558
PS, The Preventative Maintenance Monthly
ISSUE 558
MAY 1999
PS 558
5
MAY 99
no wonder the
shroud is
cracked
!
it wasn't
adjusted
properly
!
Rusty Rod Wears Brake Pads
I
f your HMMWV is going through too many
service brake pads for the miles it travels, give
the hydro-booster push rod a look-see for
corrosion.
Corrosion at the rod’s eyelet end where it con-
nects to the pedal assembly can cause a lack of
free play at the pedal, which won’t let it com-
pletely release. That means there’s a drag on the
brake rotor. In other words, the brakes are al-
ways “on.”
To remedy the problem, spray solid film lubri-
cant, NSN 9150-01-380-4470 or NSN 9150-01-
380-4235, on the push rod and brake pedal
bellcrank. Work the pedal several times until it releases to its upper stop.
echanics, if you’re tired of seeing
so many cracked fan shrouds on
HMMWVs, these tips are for you:
Eyeball the note at the top of Page
3-114 of TM 9-2320-280-20-2. When
you install the radiator fan shroud, it
must be adjusted so the edge of the
shroud is about 1
1
/
2
inches from the
back edge of the fan blades.
Additionally, there must be at least
1
/
4
inch between the fan shroud and
the tip of any fan blade.
echanics, when you set out to find
something to cover the HMMWV’s air
intake manifold during maintenance, take
a coffee break.
Yep, coffee. The plastic lid for a 34
1
/
2
-
oz coffee can fits the air intake opening
just perfectly. It doesn’t have to be taped
in place either.
Using the lid means there’s no need to
tape the opening or cut cardboard circles
to keep foreign objects out of the mani-
fold when the air horn is removed.
HMMWV . . .
Lube push rod
and bellcrank
If you spot small cracks on the
shroud that you can fix without remov-
ing the shroud, use fiberglass repair
kit, NSN 2090-00-372-6064. Instruc-
tions come with the kit.
If you must remove the shroud to
make repairs or if the cracks are large,
just replace the shroud.
If the shroud is in-
stalled without making
these adjustments, the
fan blades can hit the
shroud, cracking or shat-
tering blades.
Make sure the fan
shroud bracket is in place
and tight. The bracket
has a tendency to loosen
and fly off. Then the fan
hits the shroud, with the same damage
as above.
If the fan shroud is broken, cracked
or loose, the HMMWV is NMC until
repairs are made.
So, any time you’re under the hood
of a HMMWV, check the bracket. If
it’s loose, rivet it to the shroud. Use
the rivet gun in the HMMWV’s spe-
cial tool kit and pop rivet, NSN 5320-
01-151-1061.
Bracket tight?
PS 558
4
MAY 99
Adjust shroud for proper clearance
Oblong holes make adjustment easy
hey!
i still
need
that!
Cover intake opening with coffee lid
■
■
PS 558
5
MAY 99
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