I'm trying to do a complete clean and fluid change on my 1994 Unimount plow. I am finding that this replacement filter is a harder type plastic and is not going on that easy with the pump in the housing. I suspect that I will have to get it farther up the spout than I have it in the picture. Is there a trick to twist them on without breaking them? I will take the pump out to do it, which leads me to my next question, I understand that only two out of the four bolts mount the pump, can you tell me which two it is? Thanks again!