PS Magazine - TB 43-PS-729
PS, The Preventative Maintenance Monthly
ISSUE 729
AUGUST 2013
14
PS 729
15
PS 729
AUG 13
Dear Bonnie,
It’s not just cereal that goes snap, crackle and pop. Every time I go to
tighten a HMMWV’s brake bleeder valve, it seems like I end up destroying it!
I’ve followed every step in the TM, but Soldiers keep coming back to the
shop with leaky or broken bleeder valves.
How do we fix this problem?
SSG D.U.N.
Dear Sergeant D.U.N.,
Believe it or not, you’re not the only one with this issue.
The torque specifcation listed
in TM 9-2320-387-24-1 instructs
users to
“Tighten bleeder screw
to 60
lb-ft,
or 81 newton meters”
and TM 9-2320-387-24-2 lists the
bleeder screw torque as “6-15 lb-
ft, or 8-20 newton meters.”
TACOM
LCMC
says
that
both TMs should read,
“Tighten
bleeder screw to 60
lb-in
(7
newton meters).”
You should see this correction in the next TM change. Until then, make a note
oF the right torque in the Following TM sections:
•±
TM 9-2320-387-24-1 (Page 7-4.3, Step 4, Paragraph 7-2.1 and Page 7-4.4, Step 5,
Paragraph 7-2.1 of Change 6)
•±
TM 9-2320-387-24-2 (Page 22-10, Step 16, Paragraph 22-5 of Change 1)
HMMWV…
A Twist on Brake Bleeder Valve Torque
sn
ap
p
o
p!
c
r
a
c
k
l
e
Dump
Trucks…
hoist
cylinders
normally
leak!
Some leak
just a
little,
others leak
a little
more.
Leaks do not make your truck NMC
unless
they add up to more than
a quart a day, or if the cylinders
won’t lift an empty dump bed.
That’s because single-
ram cylinders
must
leak enough to keep
the rod coated with
oil and the seal wet.
The oil
protects
the
rod from the elements
and corrosion.
Telescoping cylinders,
like those on M91
7
dump trucks, have
seals at each section
of the cylinders that
leak/lubricate the
rod for the same
reasons.
it’s a no
brainer.
..
dump truck
hydraulic
hoist
cylinders
leak!
Tighten bleeder screw to 60
lb-in
, not
lb-ft!
are you
eating
breakfast,
too?
now
to add
milk—
Nah! just
another
torque gone bad
on a hmmwv’s brake
bleeder valve…
…and
I
followed
the guidance
in the TM!
some
Leakage
is OK!
Bonnie
729 14-15.indd
1-2
7/1/13
5:37 PM
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