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Technical Bulletin
Bulletin No.: PRO-03-18 Effective Date: 2/15/79 Cancels: N/A Page: 1 of 2
Subject: MV-2 CONTROL VALVE PRODUCT DESCRIPTION
The MV-2 Control Valve has been released and is being used at the present time by
White and I.H.C. on certain models. This is a modular-type control valve with two
buttons, which will perform the following functions:
• Tractor protection control
• Trailer service air supply
• System park
• Trailer park only
• Trailer charge with tractor spring brakes applied (tractor park only)
• Supplied reservoir selection
The valve will be serviced by spool replacement cartridges and a dual circuit supply
valve maintenance kit.
The service spool for the trailer control portion (red button) is 101569. This includes a
pre-lubricated spool and a spirol pin for attaching the button.
The spool for tractor control (yellow button) is piece No. 101570; also packaged prelubricated with spirol pin included.
The dual circuit supply valve, included in the tractor control section, is a spring loaded
valve which selects No. 1 reservoir as the supply for both control valves, unless No. 1
reservoir falls at least 25 p.s.i. below No. 2 reservoir, at which point the valve will cycle
and establish No. 2 reservoir as the supply. Dual circuit supply valve may be serviced
with a maintenance kit Piece No. 101557.
Note: Reservoir No. 1 must be the reservoir that supplies the rear tractor
axle(s).
Reservoir No. 2 must be the reservoir that supplies the front axle.
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Body assemblies will also be available in case of valves damaged by accident or fire, as
well as buttons and pins. The chart below summarizes the MV-2 piece numbers and
service items.
MV-2 Trailer Supply Valve Tractor Supply Valve Body Assembly
MV-2 Spool
101437
101438
*White only
Button Spool
Assembly
101569
101569
Dual Circuit Supply Valve Maintenance Kit – 101557
Spirol Pin to retain buttons - 238379
293510
*293557
Assembly
101570
101570
Button
293511
*293786
101571