SPOOL 1651540 - Caterpillar

Table 1
Required Tools
Item Part Number Description Qty
A 1U-5796 Pressure Differential Gauge Group(1) 1
B 6V-7830 Pressure Gauge 2
(1) 198-4240 Digital Pressure Indicator is also available.Read Testing and Adjusting, "Machine Preparation for Troubleshooting" and understand Testing and Adjusting, "Machine Preparation for Troubleshooting" in this manual before performing the following procedure.This method involves measuring the margin pressure with a differential pressure gauge while the machine is being articulated. The margin pressure is the difference between the steering pump pressure and the pressure in the load sensing line. The load sensing line connects to the flow compensator valve on the steering pump. Margin pressure must be read during machine articulation. When the machine stops articulating, you are not reading margin pressure.
Illustration 1 g03882122
(1) Pump
(2) Flow compensator valve
Connect the high-pressure port of pressure differential gauge group (A) to the quick connect port at the pump discharge pressure tap. Install a 40000 kPa (5800 psi) pressure gauge at the high-pressure port of pressure differential gauge group (A). Connect the low-pressure port of pressure differential gauge group (A) to the quick connect port at the pressure tap of the load sensing line.Note: Two separate pressure gauges (B) can be used in place of the pressure differential gauge. These gauges are tetragauges. The tetragauges read pressures from 0 to 40000 kPa (5800 psi). Connect one tetragauge to the pressure tap. Connect the other tetragauge to the pressure tap.
Start the engine. Run the engine at high idle.
Move the STIC control halfway to the right position. Check the pressure differential gauge. The gauge should stabilize at 2100 100 kPa (305 15 psi) (steering pump margin pressure).Note: If you are using the tetragauges, the steering pump pressure should be 2100 100 kPa (305 15 psi) higher than the pressure in the load sensing line. This pressure is the margin pressure. These pressures must be read during the articulation of the machine.
Stop the engine. Adjust the flow compensator valve if the pressure was not correct. Remove the cap. Loosen the locknut . Adjust the setscrew to adjust the setting of the steering pump margin pressure. Turn the setscrew clockwise to increase the margin pressure. Turn the setscrew counterclockwise to decrease the margin pressure.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.