Bendix Commercial Vehicle Systems MV-1 User Manual

®

Bendix® MV-1™ Modutrol

5-3/8”

SD-03-3411

VALVE A

VALVE B

FIGURE 1 - MV-1™ MODUTROL

VALVE C

VALVE E

VALVE D

DESCRIPTION

The Bendix® MV-1™ modutrol assembly is an integrated air
control module designed for dash mounting in a truck/tractor.
The bodies for the modutrol assembly, as well as for the
“spool” inserts, are molded of a nonmetallic, noncorrosive
material. The assembly consists of three push-pull type
valves and two optional lever type valves. All valves utilize a
spool “insert,” which can be replaced from the front of the
assembly without removal of the assembly or connecting
air lines.

The three push-pull type valves provide the following functions:

1. Tractor protection control.

2. Trailer service air supply .

3. System park.

4. Trailer park only .

5. Trailer recharge with tractor spring brakes applied.
Reference Figs. 1 & 5, valves V-1 and V-2 utilize identical

spool “inserts.” The functions of valves V-1 and V-2 are
essentially the same as the Bendix® PP-1™ control valve.
V alve V-3 utilizes a spool “insert” consisting of two valves; a
nonautomatic push-pull function similar to that of the Bendix
PP-8™ valve, and a pilot operated three-way valve similar to
that of the Bendix® SV-1™ valve.

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The optional lever type valves housed in the auxiliary control
module consist of one or two lever type valves which may be
used to control any on/off type auxiliary devices such as a
sliding fifth wheel, inter-axle lockout, etc.

The function as the lever type valves is similar to the Bendix
TW-1™ control valve. One or both of the valves may be utilized
and, if required, a nonfunctional spool insert may be replaced
by a functional spool insert at any time. Port identification
for the push-pull module is shown on Fig. 6 and for the
auxiliary module on Fig. 9.

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OPERATING MODE V-1 V-2 V-3

NORMAL RUN BUTTON IN. DELIVERY BUTTON IN. DELIVERY TO BUTTON OUT. UPPER

SUPPLIES BOTH SECTIONS TRACTOR SPRING BRAKES PORTION BLOCKS SUPPLY
OF V-3 (PP-8™ AND SV-1

™

AND TO PILOT SECTION AIR FROM V-1.

VALVE). OF PILOT VALVE (SV-1™). LOWER PILOT VALVE

TRACTOR BRAKES (SV-1™) HELD OPEN BY
RELEASED. DELIVERY FROM V-2

PERMITTING V-3 DELIVERY
TO TRAILER SUPPLY LINE.
TRAILER BRAKES
RELEASED.

SYSTEM PARK BUTTON IN. DELIVERY BUTTON OUT. EXHAUSTS BUTTON OUT. UPPER
(POSSIBLY AUTOMATIC IF SUPPLIES BOTH SECTIONS AIR FROM TRACTOR PORTION BLOCKS SUPPLY
SUPPLY PRESSURE IS OF V-3 (PP-8™ AND SV-1

™

SPRING BRAKES AND AIR FROM V-1.

LOW.) VALVE). FROM PILOT SECTION OF LOWER PILOT VALVE

PILOT VALVE (SV-1™). (SV-1™) IN EXHAUST
TRACTOR BRAKES POSITION EXHAUSTING AIR
APPLIED. FROM TRAILER SUPPLY

LINE. TRAILER BRAKES
APPLIED.

TRAILER PARK BUTTON OUT. EXHAUSTS BUTTON IN. DELIVERY TO BUTTON IN OR OUT. NO
(POSSIBLY AUTOMATIC IF ALL SUPPLY AIR FROM V-3 TRACTOR SPRING BRAKES SUPPLY AIR.
SUPPLY PRESSURE IS (PP-8™ AND SV-1

™

AND PILOT SECTION PILOT VALVE (SV-1™) IN

LOW.) VALVE). (SV-1™). TRACTOR BRAKES EXHAUST POSITION

RELEASED. VENTING TRAILER

SUPPLY LINE.
TRAILER BRAKES
APPLIED.

TRAILER RE-SUPPLY BUTTON IN. DELIVERY BUTTON OUT. EXHAUST BUTTON IN. SUPPLY AIR

SUPPLIES BOTH SECTIONS AIR FROM TRACTOR FROM V-1 IS DELIVERED
OF V-3 (PP-8™ AND SV-1

™

SPRING BRAKES AND THROUGH UPPER CAVITY

VALVE). FROM PILOT SECTION TO TRAILER SUPPLY LINE.

(SV-1™). TRAILER BRAKES
TRACTOR BRAKES RELEASED.
APPLIED.

FIGURE 2 - MODUTROL OPERA TING MODES

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