CONVERSION KT 6R8748 - Caterpillar

EMERGENCY STEERING PUMP
7. Supplemental steering pump.The supplemental steering pump (7) operates according to the position of manual/automatic panel switch (10). The manual/automatic panel switch (10) is switched to the "AUTO" position for normal machine operation. If the engine stops while there is movement of the vehicle, the flow switch (18) signals electronic control (12). The electronic control (12) turns on a magnetic switch (11) which turns on electric supplemental steering pump (7). The electronic control will also cause the steering fault light to go on and off. A light next to the selection switch goes on when the supplemental steering system has been activated.The manual/automatic switch (10) is switched to the "MANUAL" position only when the machine is towed (pulled). This switch position turns on the supplemental steering pump (7) and the supplemental steering light.
INSTRUMENT PANEL (PARTIAL)
10. Manual/automatic panel switch.The supplemental steering pump (7) gets its electric power from the vehicle batteries. When the supplemental pump is running, it gets oil from hydraulic tank (6) and moves this oil through flow control valve (16), check valve (13) and into steering valve (4). Because of the small flow of oil from the supplemental steering pump, vehicle steering is slow.
FLOW CONTROL VALVE (Between Frame, Left of the Engine)
16. Flow control valve. 18. Flow switch.Steering Metering Valve (All Machines)
The shaft (11) from the steering wheel is connected to input shaft (1) in the steering metering valve. A pin through input shaft (1) and torsion bar (7) connects the shafts. Torsion bar (7) has a pin drive in the other end that goes into grooves in drive link (8). Splines on one end of drive link (8) are in splines in the center of gear (9). Splines on the other end of the drive link are in splines in valve spool (3). Drive link (8) also is the drive for commutator (10). Turn the steering wheel and shaft (11), input shaft (1), valve spool (3), torsion bar (7), drive link (8), gear (9) and commutator (10) turn with the steering wheel.
STEERING METERING VALVE
1. Input shaft. 2. Ball. 3. Valve spool. 4. Steering valve housing. 5. Gear (inside teeth). 6. Manifold. 7. Torsion bar. 8. Drive link. 9. Gear (outside teeth). 10. Commutator.Ball (2) is in a hole in valve spool (3) and is also in the helical groove around input shaft (1). When input shaft (1) is turned, but valve spool (3) does not turn, ball (2) moves in the helical groove and moves (but does not turn) valve spool (3) a short distance. The movement of valve spool (3) is either toward gear (5) when the steering wheel is turned clockwise or toward the steering wheel when it is turned counterclockwise. When valve spool (3) is moved to the end of its travel, holes and grooves in valve spool (3) get to an alignment with holes and grooves in valve housing (4). Now, one of the openings in the steering valve to lines (12) is an outlet for the pump oil