CASE-FINAL DRIVE 1128981 - Caterpillar

There are filter inlet and filter outlet pressure taps on the transmission filter base. Refer to Illustration 1. The inlet pressure tap is also a dual purpose scheduled oil sampling (SOS) port (designated by a purple dust cap). Use this port when sampling oil for SOS purposes. To prevent damage to the seal in the port and a subsequent leak, use 169-8373 Fluid Sampling Bottle when using the fluid sampling port.
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 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.
Use the following procedure to obtain an SOS oil sample.
Start the engine. Warm up the oil until the oil reaches 47° C (116° F).
Ensure that the transmission control is in the NEUTRAL position and place the throttle in the LOW IDLE position.
Remove the dust cap. Refer to Illustration 1. Obtain an oil sample from the SOS tap using fluid sampling bottle 169-8373.
Stop the engine.
Check the hydraulic filter element for foreign materials.
Replace the hydraulic filter element.Refer to Special Publication, PEHP6001, "How To Take A Good Oil Sample" for more information about obtaining a sample of oil.Consult your Caterpillar dealer for complete information and assistance in establishing and SOS program for your equipment.Scheduled Oil Sampling (SOS) Analysis
Effective fluid cleanliness management is the single most important factor and single greatest opportunity in maximizing component life, increasing reliability and durability, and lowering component life cycle costs. Scheduled oil sampling (SOS) is an oil analysis process designed to turn fluids analysis data into usable information that can be used to help identify impending component failures before catastrophic failure actually occurs. This information is used to manage equipment and reduce operating costs. Caterpillar has trademarked the title SOS Services to insure customers of the quality, consistency, and depth of Caterpillar oil analysis services. There are four categories of oil analysis:
Component Wear Rate
Oil Condition
Oil Contamination
Oil IdentificationComponent wear rate analysis evaluates the