PS Magazine - TB 43-PS-605

PS, The Preventative Maintenance Monthly

ISSUE 605

APRIL 2003
PS Magazine - TB 43-PS-605 - Page 7 of 33
PS 605
11
Those three seals also deteriorate over time, so check each one by measuring the
depth of the depression made by the V-pack bead in the seal. If the depression meas-
ures more than 3/16 inch, get the plenum box seal replaced.
Skirt Seals
If you’re having problems with clogged air cleaner intake filter elements
(V-packs), missing fender skirt seals could be the cause. Those rubber strips are
there to seal the area between the skirts and hull.
Missing seals let dirt and dust get sucked inside the fender skirts. The engine pulls
the dirt into the intake system where it clogs up the V-packs.
All the seals are important, but pay special attention to the seals at skirts 4, 5 and
6 on the left side of the vehicle. These seals are closest to the air intake grills and
can let in the most dirt.
V-Packs
The three V-packs on all tanks not equipped with the pulse jet system (PJS) should
be removed, cleaned and inspected after every operation. V-packs on PJS-equipped
tanks are self-cleaning.
Removing the V-packs on these tanks will ruin the system.
The preferred cleaning
method is the V-pack
cleaning wand. You’ll find
info on the wand in the
“unusual conditions” sec-
tion of your -10-2 TM’s
operating instructions.
If the cleaning wand
isn’t available, shake the
V-packs, making sure not
to hit them against any-
thing harder than your
hand. Brush dirt and dust
from the elements with
your hand. Then, have the
elements properly cleaned
by your unit maintenance
folks as soon as possible.
1.
Apply chalk to the raised
portion of the V-pack bead.
2.
Install the V-pack and
secure the holding clamp.
3.
Remove the V-pack and
eyeball the plenum box
seal. There should be a
complete chalk line around
the seal from contact with
the V-pack bead.
If the chalk line is broken, the V-pack may not be sealing correctly. So, get your
mechanic to install a new seal, NSN 5330-01-098-6807. Remember to wipe the
chalk off the V-pack bead and seal after testing.
This method works especially well if you are putting new V-packs in
without
replacing the plenum box seals. But, it’s a good idea to put in new seals along with
the new V-packs whenever possible.
M1
M1A1
M1A2
M1A2 SEP
Figs 261-264 and 266
of TM 9-2350-255-24P-1 (Oct 92)
Figs 263-266 and 268
of TM 9-2350-264-24P-1 (Sep 01)
Figs 242-245 and 247
of TM 9-2350-288-24P-1 (Jul 01)
Figs 241-244 and 246
of TM 9-2350-388-24P-1 (Feb 01)
• Eyeball the bead on the front face of each V-pack ele-
ment for dents or sharp edges that could cut the plenum
box seal. Then check for buckling on the rear face of the
element. Either problem means you need a new V-pack.
• Look for broken welds and cracks in the plenum air
box. Dust trails along the welds and seams of the box are
a good sign of a leak, so tell your mechanic.
• Look for torn, cracked or missing plenum box seals. A
missing seal makes your tank NMC.
Here’s
another
way to
check the
seals:
While the
V-packs are
out, inspect
the plenum box
and elements
for potential
problems…
Chalk placed here…
…should
show up
here
Look for
dents or
buckling
Use wand to clean V-pack
No wand?
Shake
V-pack
gently
NSNs for
the seals
are listed
here…
605. 10-11 (C)
3/1/03
11:10 AM
Page 1
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