BLOCK AS 3949944 - Caterpillar

Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
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.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Perform visual checks first when you are troubleshooting a problem. Before you make these checks, stop the engine and apply the parking brake. Shift the propel control lever to the NEUTRAL position. During these checks, use a magnet to separate ferrous particles (iron) from nonferrous particles (O-ring seals, aluminum, bronze, etc), if necessary.
Check the oil level of the hydraulic oil tank.
Look for air bubbles in the oil or water in the oil immediately after the machine is stopped. Use a clear bottle or a container in order to get a sample of the oil. Refer to Operation and Maintenance Manual, "Lubricant Viscosities and Refill Capacities" for the recommended oil grade and the recommended oil viscosity.
Air bubbles may be caused by a fitting that is loose or damaged. A loose fitting or damaged fitting allows air to enter the suction side of the system and oil is also allowed to leak.
Check all oil lines, all hoses, and all connections for damage and for leaks. Look for oil on the ground under the machine.Note: If oil can leak out of a fitting or out of a connection, air can leak into the system. Air in the system is as harmful as having too little oil.