ROD AS 3009652 - Caterpillar

Hot oil and hot components can cause personal injury. Do not allow hot oil or hot components to contact skin.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Test for Margin Pressure
Table 1
Required Tools    
Part Number     Description     Qty    
1U-5796     Pressure Differential Tool Gp     1    
Illustration 1 g01687894
(A) Pressure gauge (B) High-pressure port (C) Pressure differential gauge group (D) Low-pressure port (E) Hose assembly (system pressure) (F) Hose assembly (load sensing)
Lower the bucket or any work tools to the ground. Stop the engine.
Illustration 2 g00280787
Steering Frame Lock
Install the steering frame lock.
Turn the steering wheel to the left and to the right in order to release any steering system pressure.
Slowly loosen the hydraulic tank filler cap in order to release any residual pressure. Then, tighten the filler cap.
Illustration 3 g01522687
(1) System pressure tap (2) Load sensing pressure tap
Connect 1U-5796 Pressure Differential Tool Gp to pressure tap (1) and pressure tap (2) .
Start the engine and run the engine at low rpm. Allow the hydraulic oil to reach normal operating temperature of 68° 14°C (154° 25 °F). Check for hydraulic oil leaks.
Run the engine at idle engine speed.
Raise the bucket and extend the lift cylinders to full extension. While the bucket is slowly lifted, take a pressure reading from both gauges. The measurement must be taken before the lift cylinders are fully extended. Margin pressure is the difference between discharge pressure of the implement/steering pump and the signal pressure for the implement/steering pump. The margin pressure should be 2600 100 kPa (375 15 psi).Adjusting the Margin Pressure
Illustration 4 g02347557
Implement/steering pump (Top view) (3) Locknut (4) Adjustment screw
Loosen locknut (3) . Turn adjustment screw (4) clockwise in order to increase the margin pressure. Turn adjustment screw (4) counterclockwise in order to decrease the margin pressure.
After you turn adjustment screw (4) , hold adjustment screw (4) in place and tighten locknut (3) to a torque of 125 20 N m (90 15 lb ft).
Repeat the test in order to verify that pressure is within the specified range by starting with Step 5 of the "Test for Margin Pressure".