SOCKET-41MM 2391291 - Caterpillar

Steering Check and Relief Valves
Illustration 3 g00286681
Steering check and relief valve (2) in the RELIEF position (2) Steering check and relief valve (3) Holes (10) Holes (40) Poppet (41) Orifice (42) Dump valvePressure oil of the steering cylinders is felt through holes (3) and holes (10) . If the pressure increase from the steering cylinders exceeds the relief pressure, pressure oil in holes (3) forces poppet (40) to the left. This creates a pressure drop across orifice (41) . The pressure drop causes dump valve (42) to move to the left. This allows oil flow through holes (10) into internal tank passage (7) .
Illustration 4 g00286682
Steering check and relief valve (2) in the MAKEUP position (2) Steering check and relief valve (10) Holes (11) Holes (43) Check valve (44) Seat for the check valveAfter pressure oil is dumped into internal tank passage (7) , the oil will flow across the internal tank passage and back pressure valve (6) . This oil enters holes (11) of steering check and relief valve (2) . If the pressure difference between internal tank passage (7) and the cylinder port with the highest pressure gets too high, check valve (43) will move to the right. This moves seat (44) in order to allow oil flow. The oil flows through holes (10) into the cylinder port with the lowest pressure. Back pressure valve (6) helps check valve (43) to open by holding some pressure in internal tank passage (7) . The oil pressure must shift back pressure valve (6) in order to drain to the steering hydraulic tank.Oil Flow During A Turn
Illustration 5 g00519026
Steering control valve in the right turn position (1) Steering control valve (2) Steering check and relief valve (3) Holes (4) Port to the steering cylinders for left turn "CL" (5) Port to the steering hydraulic tank for return oil "HT" (6) Back pressure valve (7) Internal tank passage (8) Port to the steering cylinders for right turn "CR" (9) Port for return oil from steering metering pump "T" (10) Holes (11) Holes (12) Springs (13) Passage (14) Amplifier spool (15) Internal cavity (16) Orifices (four) (17) Port for the pilot oil from the metering pump for a left turn "L" (18) Spring (19) Passage (20) Passage (21) Port for inlet oil from the steering piston pump "HP" (22) Passage (23) Port for pump oil to steering metering pump "P" (24) Priority spool (25) Passage (26) Plug (27) Port for load sensing oil from the metering pump "LS" (28) Spring (29) Check valve spool (30) Orifice (31) Passage (32) Pin (33) Spring (34) Port for pilot oil from metering pump for right turn "R" (35) Passage (36) Orifices (six) (37) Passage (38) Orifices (eight) (39) Directional spoolWhen the steering wheel is turned to the right, the steering metering pump stops venting all of the pilot oil ports to return oil port (9) . This increases the pressure in the pump port of the steering metering pump. At the steering metering pump, the load sensing