Just curious, if anyone can answer much appreciated.

How many pumping hours is expected from 2100 pumping pistons say from a machine that has 10 year old cylinders?

Hours I dont know but, I get about 6 to 7 months out of mine, before they start to leak water out of the box into the hopper. The pump I operate is 13 and, has never had the cylinders changed. If I pump for long periods I too wash and, refill the box on pours.

Too many variables to say.

Schwing has the hardest cyls on the block; no contest. If they put chrome on them, and oilers, they might not ever wear out; and pistons would last for years.

I had 150,000 yds on my putz and they still didn't leak. If you run a schwing? You won't belieave me LOL. But its true. Schwings are not chromed .