DIFFERENTIAL GP 4341911 - Caterpillar

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.
Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause 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.
Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine.To prevent personal injury or death, perform the following:Park the machine on a smooth, level surface.Lower the work tool to the ground and engage the parking brake.Stop the engine and remove the key.Block the wheels and install the steering frame lock.
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.
A visual inspection of the systems is one of the first steps when you are troubleshooting a problem. Before any tests are performed, visually inspect the systems for oil leaks and for damaged parts.
When possible, talk to the operator. Ask about the symptoms of the problem: machine performance, noises, smells and frequency of the problem.
Prepare the machine for troubleshooting. Refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
Check the display of the monitoring system for the following machine conditions: alert indicators, warnings and service codes.
Be aware of the work environment. An extreme work environment can greatly affect the symptoms of a machine.
Check the hydraulic oil levels in the sight gauges on both of the tanks. The 844 Wheel Tractor and the 990 Series II Wheel Loader have two separate hydraulic tanks. The tank for the implement system and the brake system is located outside the cab on the right side of the machine under the floorplate. The tank for the hydraulic fan system and the steering system is located on the left side of the cab under the floorplate. The sight gauges can be seen from the ground on either side of the machine.
Look for air in the hydraulic tank oil immediately after the