90301-ZV7-000 Honda NUT, CASTLE (Honda Code 4433827).

Measuring Cleanliness
Fluid cleanliness can be measured by taking fluid samples from various machine compartments. Your Cat dealer can analyze the samples. Particle contaminants are typically measured by particle counters. Chemical contaminants can be measured by specific analysis techniques such as oxidation, water, or soot tests. Some chemical contaminants, such as water in fuel, can interfere with the particle counters and can be counted as particles. Refer to your Cat S O S lab or to your Cat dealer for more information.The number of particles in fluids is expressed in "ISO (International Organization for Standardization)" ratings. "ISO 4406" Standard classifies fluid cleanliness by the number and size of particles in 1 milliliter of fluid. "ISO 4406" Standard measures particle size in µm (microns) and reports the resulting count in three code ranges X, Y & Z. The three code range defines the size and distribution of particles in 1 milliliter of fluid:
The first code range, X represents the number of particles equal to or larger than 4 µm per milliliter of fluid.
The second code range, Y represents the number of particles equal to or larger than 6 µm per milliliter of fluid.
The third code range, Z represents the number of particles equal to or larger than 14 µm per milliliter of fluid.An example of an "ISO 4406" particle count is 18/16/13. Cat "ISO" cleanliness recommendations are expressed as two or three codes, depending on the machine system. The three code range follows "ISO 4406" definitions and is used for liquid fuels such as diesel and gasoline. The two code system, example "ISO -/16/13", is used for certain lubricant systems. In the two code system, the first number is the number of particles equal to or larger than 4 µm per milliliter of fluid. This number is not required and may be represented by a dash (-). The second number (Y) and the third number (Z) follow "ISO 4406" definitions. Cat reports the Y and Z codes for lubricating oils to keep consistency with older data and reports.An example of the particle size and distribution of the "ISO 4406" codes is given in Table 1.
Table 1
ISO 4406 Code Number of particles in 1 milliliter of fluid
4µm and up 6µm and up 14µm and up
"ISO 18/16/13" 1300 - 2500 320 - 640 40 - 80
"ISO 21/19/17" 10000 - 20000 2500 - 5000 80 - 160 Note: Several factors affect the results of particle counts. The factors include the cleanliness of the equipment used to obtain the sample, sample techniques, the cleanliness, and type of sample container, particle counter accuracy (calibration, maintenance, and process), and the environment where the sample is procured. Samples should be taken at representative locations in the fluid circulation system or the fluid distribution system when possible. The sample should be protected adequately from contamination during transport to the lab for analysis.In addition, particle counters may count water droplets and air bubbles as particulate contamination.Note: American Society for Testing and Measurement has developed "ASTM D7619" “Standard Test Method for Sizing and Counting Particles in Light and Middle Distillate Fuels, by Automatic Particle Counter”. This test procedure was developed in 2010 to count and measure the size of dispersed dirt particles, water droplets, and other particles in 1-D and 2-D diesel fuels when the specified particle counter is used. "ASTM D7619" is also applicable to biodiesel fuels.Cleanliness Standards for Fill Fluids
Cat recommends that machine systems be maintained at the factory defined fluid cleanliness targets.Cat has established minimum fluid cleanliness targets for fuels and fill oils and for engines before they return to work after maintenance. Fluids filled into engine fill tanks are recommended to be at the target levels provided in Table 2 or cleaner. When system fill fluids are maintained at or cleaner than the "ISO" cleanliness targets, contamination-related effects will be reduced.
Table 2
Cat Recommended Fluid Cleanliness Targets(1)
Cat Recommended Cleanliness Targets for Fluids Dispensed into Engine Fill tanks Fill oils (2)
Dispensed fuels "ISO 18/16/13"
(1) The fluids should meet or exceed the cleanliness requirements of the listed ISO levels.
(2) For engine oils, when filtering the oil prior to dispensing into the engine tank, use engine oil filters of 12 micron absolute efficiency and ensure that the oil temperature is 20° C (68° F) or higher. Refer to the details given in this article.The “fill” fluids cleanliness target is not a fluid “delivery” target. The level of cleanliness for delivered fluids is not specified by Cat. Customers can work with the distributors or carriers to determine the cleanliness level of delivered fluids. However, a more effective and economic means to achieve the fill cleanliness targets is to filter the fluids prior to filling into engine tanks as compared with specifying delivery fluid cleanliness level. Follow the guidelines provided in this Contamination Control article.Although older technology machines may not be able to maintain the recommended cleanliness targets of advanced models, the same contamination control intervention measures such as filtration and subsequent service procedures should be used on all Cat products.Note: When particle counting new multi-viscosity engine oils, there may be difficulties achieving cleanliness targets. Optical particle counters cannot distinguish between particulate contaminants and additives. Do not use optical particle count for the evaluation of used engine oils because soot levels render oil too dark for optical particle counters. Soot levels in used engine oils should be evaluated by using S O S Services Oil Analysis.When filtering engine oil before dispensing into the engine tank or when engine oil kidney looping filtration is done, follow these recommendations:
Use engine oil filters of 12 microns absolute efficiency. Cat Ultra High Efficiency Lube filter is recommended. Consult your Cat dealer for the most current part number.
Ensure that the temperature of engine oil is 20° C