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.
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