I've done searches on TBN and read up as much as I can find on changing the hydro/trans fluid and filter on my cab 3520. Now you all are going to think this stupid question should not even need asked. Think what you may, I'm asking anyway. To take the suction filter off do I have to remove 3 bolts from the housing or does the end of the housing have knurled ridges on it for a reason as in twist off? I have the tech manual which says nothing about this and the parts manual in which the picture shows only the filter itself, not the housing. In other posts I read about needing to take the brace off of the suction line that goes into the top of the filter housing, so that make me think the 3 bolts along with the entire housing has to come off, yes? Also, since a person can never get every last bit of any kind of fluid out, how much was needed to put in? I have 7 gal ready to go. Thanks in advance!