Don't be too concerned about the 102mm measurement. It IS important to fill it up with enough oil that the compression assembly takes some effort to install into the cartridge (which is filled with oil). Again, you are essentially filling the internal cartridge somewhat over full, until it is a few mm over the last ridge on the cartridge (this is where the compression "stack" is completely immeresed in oil); measuring from the top is still a good idea, your manual was written by smart folks so obey as best you can. Once you do this and successfully screw the compression assy into the cartridge you will then "bleed" the excess oil from the cartridge by compressing the dampening rod completely a few times; excess oil will escapre from the two holes at the top of the cartridge assembly ( and sometimes air).
Once thing to note, you don't just fill the cartridge with oil, you need to "bleed" the air out of it. This is done by (hopefully you have the cartridge in a vise to hold it) slowly compressing the rod through it's stroke. You can actually hear the air in the cartridge and can view the bubbles coming up to the top with a fashlight while looking into the top of the filled cartridge. I usually wait a few minutes between strokes to let the bubbles come to the top. If there is still air in the oil after 6 strokes, you can hang it somewhere to let the air come to the top. Sometimes this takes 15 minutes or more, but this IS an important step so please try your best to get this right! Once you let it hang/sit it should be much easier the get the air out of it.
PLEASE BE PATIENT!!
some helpful info:
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