LUG 1105887 - Caterpillar

Introduction
When the main pumps have been serviced or the hydraulic oil has been replaced, air will need to be removed. Use the following procedure to remove air from the hydraulic system:Machine Preparation
Clear all personnel from the machine and from the area around the machine.
To avoid system damage, make sure that the hydraulic pump is properly filled with hydraulic oil before start-up.
Start the engine.
Illustration 1 g02449876
Engine speed dial
Set the engine speed dial at "10".
Lower the left console.
Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.
Fully depress the service brake pedal until the service brake pedal locks mechanically.
Lower the stabilizers and the blade tip.
Fully extend the bucket cylinder and place the bucket on the ground.
Engage the swing lock pin.
Stop the engine.
Release the pressure in the hydraulic system.Note: Refer to Testing and Adjusting, "System Pressure - Release".
Raise the left console.
Illustration 2 g02350768
Top right view of main hydraulic pump and swing pump (1) Vent plug
Personal injury can result from hydraulic oil pressure and hot oil.Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system.Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.
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.
While the engine is stopped, remove vent plug (1) .
Fill the main pumps with oil.
Install vent plug (1) and tighten to the specified torque.
Start the engine.
Illustration 3 g02452604
Engine speed dial
Set the engine speed dial at "1".Adjustment Procedure
Raise the bucket off the ground.
Stop the engine and slowly lower the boom until the bucket is on the ground. This step pressurizes the hydraulic tank.
Slowly loosen vent plug (1) until oil begins to flow around vent plug.
Tighten vent plug (1) to the specified torque.