Anything that alters the spacing of the cotton strings that comprise the cotton filtering mesh ruins the filter. Using a water hose to dislodge the dirt. Using any type of brush,soft or stiff bristle, can alter the cotton mesh size. Using compressed air to dislodge particles or trying to speed up the drying process alters the mesh size. Moving any of the strings that comprise the cotton mesh, moves one string closer to another but it also moves that string away from the neighboring string making the passage way or mesh larger at that one mesh location. Particles of dirt or sand will find these enlarged pores in the mesh and enter your engine.
Not getting the cotton mesh completely oil free when cleaning will allow the filter to pass larger particles than what the filter was designed to trap. The cotton strings comprising the filtering mesh must be clean enough to become "fuzzy" after cleaning and drying. Any oily residue or soap left after cleaning will prevent the strings from becoming "fuzzy". The fuzz from individual strings tend to fill in the square holes between the cotton strings and make the filter trap the smaller particles.
I do not like to use the K&N spray oil, I like to use the K&N oil in the squeeze bottle. Use K&N oil!!!!. I think that it is some type of colored vegetable oil. It is not ATF.
1. I like to place a bead of oil along the full length of each pleat on the outside of the filter and allow the oil to "wick" to the adjacent cotton mesh.
2. After placing a bead of oil along the peak of each pleat, wait about 5 to 10 minutes and look on the inside of the filter and see if the oil has wicked to the bottom of each pleat. If it has not repeat step 1.
3. If you are determined to use spray oil, spray only from the outside of the filter. DO NOT SPRAY THE INSIDE OF THE FILTER TO MAKE IT PINK!!
4. After spraying, wait 5 to 10 minutes and look at the inside of the filter to see if the oil has wicked all the way through the cotton mesh. If the oil has not wicked all of the way through the cotton, spray the outside again and wait 5 to 10 minutes.
5. Repeat step 4 until the oil has wicked all of the way from the outside to the inside of the cotton mesh.
If you spray the inside after spraying the outside, you do not have any way of knowing if the cotton has the proper saturation of oil. Allowing the oil to wick from one side to the other insures the cotton is completely saturated. It is better to over oil than to under oil.
I like to hang the filter up for a day or so to allow the oil to drip off in case I over oiled it. If you are using an outer ware and the outer ware becomes oily the outer ware will quickly plug up with fine dust and choke the engine similar to putting a plastic bag over the K&N. An outer ware must remain oil free to work properly.
