TM 5-3805-291-23-1
THEORY OF OPERATION - CONTINUED
0003 00
STEERING SYSTEM - CONTINUED
(1)
Steering cylinders crossover relief valve is located on back left side of steering control valve when facing
back left side of machine.
427-C1801
(2)
Steering cylinders crossover relief valve relieves shock loading in steering system. Crossover relief valve
operates when steering system is in NEUTRAL or when steering system is articulating machine.
(3)
Steering cylinder pressure is sensed in two steering control valve passages. Steering cylinder pressure is
also sensed on two valve faces.
(4)
When steering cylinders are moved by external steering forces, pressure in passages can increase suddenly.
(5)
A pressure increase in upper passage acts on upper valve face. If pressure is greater than valve setting,
poppet moves left, compressing spring. Pressure is relieved to lower passage through holes.
(6)
If pressure in lower passage is greater than pressure setting of crossover relief valve, pressure acts on
lower valve face and sleeve face.
(7)
Sleeve and poppet move left against spring. Pressure in lower passage is relieved to upper passage through
holes.
(8)
Spring chamber is connected to hydraulic oil tank through drain hole.
(9)
Pressure setting of steering cylinders crossover relief valve is adjustable.
0003 00-128
