PS Magazine - TB 43-PS-710

PS, The Preventative Maintenance Monthly

ISSUE 710

JANUARY 2012
PS Magazine - TB 43-PS-710 - Page 9 of 33
14
PS 710
JAN 12
15
PS 710
JAN 12
Hardware
Comes Up
Short
T
he brake relay valve assembly, NSN 4820-01-359-6577, and air pressure relay valve
assembly, NSN 2530-01-332-2420, on your HET semitrailer come with brand new hardware
for installation.
So you can just toss out the old hardware, right? Not so fast!
Turns out the tapping screw and machine bolts that come with the new assemblies are
too short. You’re going to need that old hardware to mount the new assemblies.
So what do you do if the old hardware is damaged? Fig 27 of TM 9-2330-381-24P (Jun 09)
gives the NSNs for the right size hardware.
The brake relay valve assembly’s tapping screw (Item 2) comes with NSN 5305-01-358-
8406. NSN 5306-01-359-0126 brings 100 machine bolts (Item 22) for the air pressure relay
valve assembly.
When installing either of the valve assemblies, make sure you apply a few drops of
locking compound to the hardware’s threads. Then torque both the screw and bolts to 50
to 70 lb-in.
Note
When torquing the
two valve assemblies to
their L-brackets, there’s a
tendency for the bolts on
top of the assemblies to
come loose. So, once the
brake assembly valve is in
place, remove the 2 bolts
on top, add a few drops
of locking compound
to the threads, and re-
torque them to 50-70 lb-
in.
No locking compound
is needed for the 4 bolts
on top of the air pressure
relay valve. Just re-torque
them to 50-70 lb-in after
attaching the valve.
•±
Units must ride with the antenna whip in the
down position when driving the MRAP.
•±
Do not touch the power lines! Most lines are not
insulated.
•±
Scan for low-hanging lines in the area. Be aware
of the hazards they might present.
•±
Make sure there’s enough clearance between the
MRAP—including any antennas—and any power
lines. The driver and passengers need to work as
a team and keep an eye out for suspect lines.
•±
Avoid making radio transmissions while crossing
under power lines. An electric charge from the
power lines can pass to the vehicle without
direct contact.
Power Line
Reminder
After torquing brake valve assembly to L-bracket, remove
these two bolts, add locking compound and re-torque to
50-70 lb-in.
After attaching air pressure
relay valve assembly, re-torque
4 top bolts to 50-70 lb-in
M1000 HET Semitrailer…
MRAP Vehicles…
Power Line
Reminder
hey!
where
are you guys
goin’?
till you
can get the
right size
mounting
hardware,
we’re outta
here!
accidental contact with overhead
power lines is
still
a problem in
southwest asia (swa).
that’s mainly because new power
lines are continually going up as the
region’s infrastructure is rebuilt.
but mrap users can
reduce
power line risk by
taking the following actions to protect both
crew and passengers…
know your
mrap
vehicle’s
height
limitations.
make sure there’s
safe clearance from
overhead power lines.
the power line clearance can
be
10, 15,
or
20 feet
, depending
upon the voltage on the line.
710 14-15.indd
1-2
11/23/11
3:05 PM
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