Obtaining S·O·S Oil Samples
Before you obtain an S·O·S oil sample, operate the machine until the oil is warm and the oil is well circulated. Then obtain the S·O·S oil sample.
Do not take the oil sample from the drain stream, because a stream of dirty oil from the bottom of the compartment will contaminate the sample. Likewise, never dip an oil sample from an oil container or pour a sample from a used filter.
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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 designated pump for oil sampling and a designated pump for coolant sampling. Failure to do so may cause a false analysis which could lead to customer and dealer concerns. |
There are two 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 for pressurized oil systems.
- Use a sampling gun 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. Whenever you obtain the samples, obtain the samples from the same point. This makes the samples more representative of the oil that is in the system.
In order to obtain an oil sample from the engine compartment, 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.
In-line sampling valves cannot be used on nonpressurized oil systems such as differentials and final drives. Use of the sampling gun is the preferred method for nonpressurized oil systems.
Refer to the Operation and Maintenance Manual, "Maintenance Interval Schedule" for the proper interval.
The S·O·S oil analysis is composed of four basic tests:
- Wear metal analysis
- Infrared analysis for oil condition
- Tests for contamination of the oil by fuel, by water, and/or by antifreeze
- Particle Count for hydraulics, transmissions and other gear compartments
Consult your Caterpillar Dealer for complete information and assistance about the S·O·S oil analysis program.