Case Magnum 7210, Сервисный бюллетень

Страница: 17 / 26

Service Bulletin NTR SB 026 96
Magnum Hitch Diagnostic Codes and Service Manual update
Page 17 of 26
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HITCH VALVE COMPONENTS AND FUNCTION
PILOT
PRESSURE
INLET
LEVER
LOCK C
H
E
CK
SPRING
PLUNGER
SPOOL
Hitch valve solenoid
Moves the solenoid plunger.
TO LUBE
The solenoid plunger must be adjusted (centered) to prevent the hitch from drifting up or down
when the solenoid is not powered. The solenoid plunger controls the hitch valve pilot spool.
Raise - The solenoid plunger shifts to the right to raise the hitch.
Lower - The solenoid plunger shifts to the left to lower the hitch.
Spec:
Pin A to pin C ---- 3.8 - 4.2 OHMS
Pin B to pin C ---- 3.8 - 4.2 OHMS
- If the plunger in the solenoid valve is off center to the right, the hitch will drift up.
-
If the plunger in the solenoid valve is off center to the left, the hitch will drift down.
-
If the plunger sticks, the hitch may be slow to respond or continue to drift when the up /down
switch is released.
Pilot spool
Raise -
Once the pilot spool is shifted to the right, it then directs regulated pressure to the left end
of the control spool. The control spool shifts right to raise the hitch.
Lower - Once the pilot spool is shifted to the left it then directs regulated pressure to the right end
of the control spool. The control spool shifts left to lower the hitch.
-
If the pilot spool sticks to the right, the hitch will drift up.
-
If
the pilot spool sticks to the left, the hitch will drift down.