| NOTICE |
|---|
These recommendations are subject to change without notice. Consult your local Caterpillar dealer for the most up to date recommendations. |
Caterpillar has developed a maintenance management tool that evaluates oil degradation and detects the early signs of wear on internal components. The Caterpillar tool for oil analysis is called S·O·S oil analysis and the tool is part of the S·O·S Services program. S·O·S oil analysis divides oil analysis into four categories:
- Component wear rate
- Oil condition
- Oil contamination
- Oil identification
Component Wear Rate analysis evaluates the wear that is taking place inside the lubricated compartment. The S·O·S Services analyst uses the results of elemental analysis and particle count tests to evaluate the wear. Trend analysis and proprietary wear tables are then used to determine if wear rates are normal or abnormal.
Oil Condition analysis is used to determine if the oil has degraded. Tests are done to look at the oxidation, sulfation, and viscosity of the oil. The S·O·S Services analyst uses established guidelines or trend analysis to determine if the oil has reached the end of its useful life.
Oil Contamination tests are performed to determine if anything harmful has entered the oil. This analysis relies on the results from the following tests: elemental analysis, soot, particle count, fuel dilution, water, and glycol. The S·O·S Services program has guidelines for the levels of contamination that are allowed in Cat engines.
Oil Identification is another very important part of the S·O·S oil analysis program. The wrong oil in an engine can severely damage major components. The S·O·S Services analyst uses elemental analysis and viscosity results to identify key characteristics of the oils.
These four types of analysis are used to monitor the condition of your equipment, and to help you identify potential problems. A properly administered S·O·S Services oil analysis program will reduce repair costs and the program will lessen the impact of downtime.
The S·O·S oil analysis program uses a wide range of tests to determine the condition of the oil and the condition of the lubricated compartment.
Guidelines that are based on experience and a correlation to failures have been established for these tests. See the following chart for the guidelines. Exceeding one or more of these guidelines could indicate serious fluid degradation or a pending component failure. A trained person at your Caterpillar dealership should make the final analysis.
Note: Cooling system problems will also reduce the life of engines. S·O·S coolant analysis together with S·O·S oil analysis provide a complete and accurate method for monitoring the health of all engine systems. Refer to the S·O·S Services coolant analysis information in this publication. A properly administered S·O·S Services program will reduce repair costs and lessen the impact of downtime.
| S·O·S Oil Analysis Guidelines | |
|---|---|
| Test Parameter | Guideline |
| Oxidation | (1) |
| Soot | (1) |
| Sulfation | (1) |
| Wear Metals | Trend Analysis and Cat Wear Table (1) norms |
| Water | 0.5% maximum |
| Glycol | 0% |
| Fuel Dilution | Based on viscosity (1) and GC (2) fuel dilution in excess of 4% |
| Viscosity "ASTM D445" measured at 100° C (212° F) | +/-3 centistokes (cSt) change from new oil viscosity. |
| ( 1 ) | Acceptable values for these parameters are proprietary to the S·O·S oil analysis program. |
| ( 2 ) | Gas Chromatograph |
Consult your Caterpillar dealer for complete information and assistance about the S·O·S oil analysis program.
Obtaining S·O·S Oil Samples
Before you obtain an S·O·S oil sample, operate the engine until the oil is warm and the oil is well circulated. Then obtain the S·O·S oil sample.
In order to obtain a good oil sample, do not take the oil sample from the drain stream. The drain stream method can allow a stream of dirty oil from the bottom of the compartment to contaminate the sample. Likewise, never dip an oil sample from an oil container or pour a sample from a used filter.
There are two acceptable ways to obtain S·O·S oil samples. The following methods are listed in the order that is preferred:
- Use an in-line sampling valve on the pressurized oil manifold.
- Use a sampling gun (vacuum pump) that is inserted into the sump.
Use of the in-line sampling valve is the preferred method. This method provides samples that are less likely to be contaminated.
In order to obtain an oil sample from the engine, it may be necessary to increase the engine's speed. Normally, the oil sample is taken at low idle. If the flow rate is too low, increase engine speed to high idle in order to obtain the oil sample.
| NOTICE |
|---|
Do not use the same vacuum sampling pump for extracting oil samples that is used for extracting coolant samples. A small residue of either type sample may remain in the pump and may cause a false positive analysis for the sample being taken. Always use a separate pump for oil sampling and a separate pump for coolant sampling. Failure to do so may cause a false analysis which could lead to customer and dealer concerns. |
Oil Sampling Interval
Take the oil samples as close as possible to the standard intervals. In order to receive the full value from S·O·S oil analysis, you must establish a consistent trend of data. In order to establish pertinent history of data, perform consistent oil samplings that are evenly spaced.
| Compartment | Engine |
| Recommended Sampling Interval | 24140 kilometers (15000 miles) (1) (2) |
| Sampling Valve | Yes |
| Oil Type | DEO, DEO-ULS |
| Recommended Oil Change Interval | (3) |
| ( 1 ) | Under certain conditions, the Caterpillar dealer or the Operation and Maintenance Manual may allow a longer interval between oil samplings. |
| ( 2 ) | Severe applications may require a more frequent sampling interval. |
| ( 3 ) | Consult the Operation and Maintenance Manual that came with your engine for the recommended oil change intervals. |
Consult your Caterpillar dealer for complete information and assistance in establishing an S·O·S Services program for your equipment.
More Frequent S·O·S Sampling Improves Life Cycle Management
Studies have revealed that obtaining oil samples at every 24140 kilometers (15000 miles) is too long a time interval in some applications in order to predict potential failure modes. In severe applications, more frequent oil sampling is recommended. Severe service for lubricated compartments occurs at high loads, in high temperatures, and in dusty conditions. If any of these conditions exist, sample the engine oil at 16093 kilometer (10000 mile) intervals. These additional samples will increase the chance of detecting a potential failure.
Determining Optimum Oil Change Intervals
Sampling the compartments at every 16093 kilometers (10000 miles) provides information for oil condition and for oil performance. This information is used to determine the optimum usable life of a particular oil. Also, more points of data will allow closer monitoring of component wear rates. Close monitoring also allows you to obtain the maximum use of the oil. For detailed information on optimizing oil change intervals, please consult your Caterpillar dealer.
Optimizing the Component Life Cycle
An increase in the number of oil samples provides a better definition of the trends in data between oil change intervals. More oil samples will allow you to closely monitor wear patterns of components. This action will ensure that the full lives of the components are achieved.