MWO-9-2320-272-35-1
MODIFICATION OF 5-TON M939, M939A1, M939A2 SERIES FAMILY OF VEHICLES (FOV)
M939 BRAKE STABILIZATION PROGRAM (RETROFIT OF ANTI-LOCK BRAKE SYSTEM (ABS) FOR M939 FOV); MODIFICATION WORK ORDER
JANUARY 2007
CHANGE 1
MWO-9-2320-272-35-1 - Page 21 of 109
MWO 9-2320-272-35-1
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(119)
Remove air compressor discharge tube from wet tank to 1/2-in. tube union on crossmember.
Remove existing screws and loop clamps supporting tubing to crossmember as shown in
figure 48.
(120)
Remove tube elbow from wet tank inlet port as shown in figure 48.
(121)
Cut existing air compressor discharge tubing 12-inches in front of frame crossmember as shown
in figure 49. Deburr open end of tubing and clean outside of tubing to allow for installation of
new fitting.
(122)
Install WBPDVS209P-8-4 reducing bushing and WBPDN1178DF 250 psi safety valve in top port
of WBPD2203P-8 union tee as shown in figure 49.
NOTE
NOTE
Perform step 123 for M939/A1 vehicles. Perform step 124
for M939A2 vehicles.
(123)
Install WBPDVS68AB-8-8 connector on union tee (WBPD2203P-8) and connect existing tube to
connector with sleeve and nut as shown in figure 49.
(124)
Install WBPDVS68AB-12-8 connector on union tee (WBPD2203P-8) and connect existing tube
to connector with sleeve and nut as shown in figure 49.
NOTE
NOTE
Different vehicles will have different length of air dryer
hoses.
(125)
Install fixed end of new air dryer hose to union tee (WBPD2203P-8) as shown in figure 49. Route
hose across crossmember to passenger side and secure with WCND7-8X3-8 clamp,
WSH3-8-24X125G8 screw, two WWF3-8 washers, and WNHL3-824G8 locknut as shown in
figure 49.
NOTE
NOTE
Perform step 126 for M939/A1 vehicles. Perform step 127
for M939A2 vehicles.
(126)
Install air dryer fittings as follows: control port – WBPDVS269NTA-4-2 elbow; inlet port –
WBPDVS222P-8-8 extender and WBPDVS149F-8-8 elbow; outlet port – WBPDVS269AB-8-8B
elbow as shown in figure 50.
(127)
Install air dryer fittings as follows: control port – WBPDVS222P-2-2 adapter and WBPDVS149F-4-2
elbow; inlet port – WBPDVS222P-8-8 extender and WBPDVS149F-8-8 elbow; outlet port –
WBPDVS269AB-8-8B elbow as shown in figure 50.
NOTE
NOTE
Perform steps 128 and 129 for M939A2 vehicles.
(128)
Remove air dryer. (Refer to TM 9-2320-272-24.)
(129)
Remove heater harness wiring attached to passenger side frame rail up to Y-connector.
(Refer to TM 9-2320-272-24.)
NOTE
NOTE
Perform steps 130 through 132 for all vehicles except
M936/A1/A2.
(130)
Position WHMB300245AD air dryer mounting bracket on forward side of crossmember. Ensure
that top of mounting bracket is 1/4-in. to 1/2-in. below top of crossmembers flat surface. Using
air dryer mounting bracket as a template, locate, mark, and drill three 25/64-in. diameter holes
in crossmember as shown in figure 51.
(131)
Install mounting bracket (WHMB300245AD) on crossmember with three WSH3-8-24X125G8
screws, six WWF3-8 washers, and three WNHL3-8-24G8 locknuts as shown in figure 51.
Tighten locknuts 30-45 lb-ft.
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