PISTON 1211541 - Caterpillar

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.
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.
Illustration 1 g02825837
Pump compartment (1) Case drain hose (2) Fitting
While the engine is stopped, remove case drain hose (1) from fitting (2) at the top of the main pump housing.
Remove fitting (2) from pump housing.
Fill the main pumps with oil.
Inspect the O-Ring seal on fitting (2). If the seal is damaged, replace the seal.
Install fitting (2) in the pump housing.
Install case drain hose (2) onto fitting (1) .
To avoid system damage, make sure that the hydraulic pump is properly filled with hydraulic oil before start-up.
Start the engine.
Place the engine at low idle position. Raise the boom and hold the boom in this position.
Stop the engine and slowly lower the boom until the bucket is on the ground. This action pressurizes the hydraulic tank.
Slowly loosen case drain hose (1) until oil begins to flow from the opening.
Tighten the case drain hose to the specified torque.