TAG 4941637 - Caterpillar

Illustration 1 g01104968
Location of panel for access to pressure taps
Illustration 2 g01205431
Location of pressure taps (1) Pressure tap for steering pump pressure. (2) Pressure tap for the load sensing oil.
Illustration 3 g01105062
Connect the high pressure port (7) of the 1U-5796 Pressure Differential Gauge Group (5) to the quick connect port at the pump discharge port (1) . 198-4240 Digital Pressure Indicator is also available. Install a 25000 kPa (3625 psi) pressure gauge (3) at the high pressure port (4) of the 1U-5796 Pressure Differential Gauge Group . Connect the low pressure port (6) of the 1U-5796 Pressure Differential Gauge Group (5) to the quick connect port at the pressure tap (2) of the load sensing line.Note: Two separate 6V-7830 Pressure Gauges can be used in place of the pressure differential gauge. These gauges are tetragauges. The tetragauges are capable of reading pressures from 0 to 40000 kPa (5800 psi). Connect one tetragauge to pressure tap (2) . Connect the other tetragauge to pressure tap (1) .
Start the engine. Hold the work tool in the fully tilted back position while the engine is operating at high idle in order to warm the hydraulic oil. Hold the work tool in the tilted position until the reading on the hydraulic oil temperature gauge is between the first mark and the second mark.Note: Do not stall the work tool in the TILT position for more than ten seconds. If necessary, release for ten seconds and repeat the procedure.
Articulate the machine fully and engage the parking brake. Run the engine at high idle. Turn the steering wheel in the opposite direction of articulation. Hold the steering wheel in the fully turned position while the machine is articulating. The needle on the differential pressure gauge will bounce between readings. The needle should stabilize at 2400 100 kPa (350 15 psi) (steering pump margin pressure).Note: If you are using the tetragauges, the steering pump pressure should be 2400 100 kPa (350 15 psi) higher than the pressure in the load sensing line. This is the margin pressure. These pressures must be read during the articulation of the machine.
Illustration 4 g01104934
Stop the engine. Adjust the flow compensator valve if the pressure was not correct. Loosen locknut (8) . Turn adjustment screw (9) in order to adjust the setting of the steering pump margin pressure. Turn the adjustment screw clockwise in order to increase the margin pressure. Turn the adjustment screw counterclockwise in order to decrease the margin pressure.
Hold adjustment screw (9) in place and tighten locknut (8) .Reference: Refer to the Service Manual module Testing and Adjusting, "Piston Pump (Steering) Low Pressure Standby - Test and Adjust" for the machine that is being serviced.Note: If the margin pressure is set above the specification, the performance of the steering will become too responsive and jerky. Poor modulation will result. If the margin pressure is set below the specification, the performance of the steering will become sluggish and less responsive.