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 19 of 109
MWO 9-2320-272-35-1
17
(92)
Locate manifold on passenger side frame rail across from front relay valve. Remove two white
vent tubes and fittings from manifold and install two WTFD1-4HHPBV plugs in manifold as
shown in figure 36.
(93)
Remove rear relay valve (figure 31). (Refer to TM 9-2320-272-24.)
(94)
Install rear relay valve (WHMB400211HA) on existing bracket with two WWF3-8 washers and
WNHL3-8-24G8 nuts as shown in figure 37. Tighten nuts 30-45 lb-ft.
(95)
Extend green 1/2 in. tube supply line to port No.1 of ABS rear relay valve by splicing and adding
a 20 in. length of WPFT-8B-500 new 1/2 in. tubing as shown in figure 37.
(a) Locate original 1/2 in. green tubing by tracing disconnected end from ABS rear relay valve
through crossmember. Measure 4 in. forward of crossmember along 1/2 in. green tubing.
(b) Cut 1/2 in. green tubing at this point and discard.
(c) Connect WPFT-8B-500 new 20 in. length of tubing to existing 1/2 in. green tubing, using
WBPD62NTA-8 (Kit 21) 1/2 in. union.
(d) Route WPFT-8B-500 new 20 in. length of tubing back through crossmember as originally
routed.
(e) Install new WBPD63NTA-8 insert, WBPD61NTA-8 compression nut, and WBPD60NTA-8
sleeve on WPFT-8B-500 new 20 in. length of tubing.
(96)
Connect WPFT-8B-500 new 20 in. length of tubing to connector on port No. 1 of rear relay valve
(WHMB400211HA) as shown in figure 37.
(97)
Connect existing hose from frame rail to elbow in port No. 2 of rear relay valve
(WHMB400211HA) as shown in figure 37.
(98)
Connect existing hose from rear-rear axle manifold to connector on port No. 2 of rear relay valve
(WHMB400211HB) as shown in figure 37.
(99)
Remove existing tube from adapter in tee on inside of driver’s side frame rail as shown in
figure 38.
(100)
Route WPFT-6B-500 tube from existing adapter on tee to elbow on port No. 4 on rear relay valve
(WHMB400211HA) and install on rear relay valve with sleeve and nut as shown in figures 38
and 37.
(101)
Install other end of tube in adapter on tee with WBPD63NTA-6 insert, WBPD60NTA-6 sleeve,
and WBPD61NTA-6 nut as shown in figure 38.
(102)
Remove existing white tube and fitting from intake stack and install WTFD1-2HHPSV pipe plug
in opening as shown in figure 39. Remove or cut tubing as necessary.
NOTE
NOTE
Perform steps 103 through 107 for forward-rear axle.
(103)
Remove existing 1/2-in. green tube from forward-rear drive axle manifold block and driver’s side
service brake chamber as shown in figure 40.
(104)
Remove existing 1/2-in. orange tube from forward-rear drive axle manifold block and passenger
side spring brake chamber as shown in figure 40.
NOTE
NOTE
It may be necessary to remove insert from elbow for
installation.
(105)
Remove existing adapter from forward-rear drive axle manifold block (passenger side) as shown
in figure 40, and install WBPDVS269NTA-8-6 elbow facing forward on manifold block as shown
in figure 42.
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