WHEEL-REAR 2704457 - Caterpillar

Caterpillar recommends using Scheduled Oil Sampling (S O S), at regularly scheduled intervals, to complement a good preventive maintenance program.The Caterpillar Scheduled Oil Sampling Program, (S O S), was developed to help Caterpillar users realize the highest possible value from their equipment by minimizing repair costs and maximizing availability. The S O S program is a series of diagnostic tests which analyze used lubricating oils from the oil wetted compartments of the equipment. By analyzing the used oils, problems may be identified early, before extensive component failure occurs. This reduces repair cost and downtime.The S O S program is coupled with a wide range of repair options so that when a problem is identified, an appropriate matched repair plan is available. This offers the user a more complete service to minimize repair costs and schedule down-time. S O S can also measure the effectiveness of the user's maintenance program. Obtain S O S SampleThere are several methods used to obtain S O S samples. Sampling methods recommended are in preference order. If one of the first two methods is not feasible, then use the drain stream method.* Use an in-line sampling valve.* Use a sampling gun inserted into the sump.* Use the drain stream method when changing oil.When using the drain stream method to obtain an oil sample, take the sample after some oil has drained out and before the final drain oil. The oil at the beginning or end of the drain stream is not mixed well enough to be representative of circulating oil in the compartment and may carry debris that can give false S O S analysis results.S O S Analysis
S O S is composed of three basic tests:* Wear Analysis* Chemical and Physical Tests* Oil Condition AnalysisWear Analysis monitors the components wear rates by measuring wear elements and contaminants found in the used oil. Through monitoring the used oil, normal component wear trends are determined. Many failures can be identified when wear trends and/or contaminants significantly exceed past trends.Detectable failures are those caused by component wear and gradual dirt contamination. Wear analysis is not able to predict failures due to component fatigue, sudden loss of lubrication, or sudden ingestion of a large amount of dirt since failures of this nature occur too rapidly.Chemical and Physical Tests are used to determine whether the used oil has been contaminated with water, fuel or antifreeze and if these contaminants exceed maximum limits.Oil Condition Analysis determines the degree of deterioration of the used oil by measuring the amount of sulfur products, oxidation, nitration and soot present in the used oil. It also can monitor additive depletion and detect ethylene glycol, Dowtherm and butyl cellosolve contamination.Oil Condition Analysis can help regulate (reduce, maintain or extend), oil change intervals for a specific machine/engine in a given application. Oil Condition Analysis must always be used with Wear Analysis and the Chemical and Physical Tests.