PISTON AS 1915711 - Caterpillar

Removal Procedure
Personal injury can result from hot oil or hot components.At operating temperature, oil is hot and under pressure. Hot oil can cause burns.Remove the fill cap only when the engine is stopped, and the fill cap is cool enough to touch with your bare hand.Do not allow hot oil or components to contact skin.
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 attachments have been lowered, 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.
Release the system pressure. Refer to Operation and Maintenance Manual, "System Pressure Release".
Drain the hydraulic tank into a suitable container for storage or disposal. Refer to Operation and Maintenance Manual, "Hydraulic Tank Oil - Change - Hoist and Brake System".
Illustration 1 g02138140
Remove bolts (1), cover (2), and gasket (3).
Illustration 2 g02138261
Remove relief valve (4) and relief valve (5). Installation Procedure
Install relief valve (5) and relief valve (4) in the reverse order.
Tighten relief valve (5) and relief valve (4) to a torque of 165 15 N m (122 11 lb ft).