Got my p50 linepump thurs aft and slammed 192meters thru her on fri What a great feeling to pump place and finish

that much volume with all your own equipment and guys Fuck ya even though we were finishing till 5 am and I can 

still barely walk It was awesome 4 inch slick line ya its heavy but it doesnt plug up love it

I used 80ft 4inch pipe to a 90 degree then another 120ft of 4 inch to a reducer with 4 by 25ft 3 inch hose we had to simple plug ups at the reducer easy Started at 830 finished pumping at 4pm Get to do it all over again on Monday cant wait im sure it wont be quite so eeasy once the novelty wears off but for now its great

Water box is supposed to be filled with water or hydraulic fluid  

water thats , y its called a water box, or white soilable oil

If you are running polyurethane cups on hard chrome cylinders, hydraulic oil is best. Water can be sucked back into the hydraulic cylinders through the shaft seals when the hot system oil cools down. Oil in the hydraulics can screw oil pumps very quickly. Also in cold areas oil may not freeze like water. If you have rubber cups like Putz or Schwing, you must use water in the "flush box"

Do you know what type of cups your P50 has in it? 

Some pumps actualy have a system where a small amount of hydro oil is sprayed in to the waterbox from time to time.. With these kind of pumps you can get quite an oily flushbox..

i have seen cups swell up, when using hydraulic oil. and then they wear out in no time. water gets sucked into the system through the chevron eals on the diff. cylinder, when it's cooling down and pulls a vacuum. you should replace chevrons once a year. the hydraulic system is no match for a material cylinder full of ice, make sure you empty the waterbox completly, when it's cold