Very simple question guys, 

What are the common symptoms associated with worn material cylinders?

Also, Ive got an 01 Schwing 34 meter with its material cylinders never replaced. At this point, would it make any sense to flip them? Or should I go with brand new ones...

new cups leak water  into hopper.  dirty water after a truck or two.  odd wear of cups.  take a pic inside the barrel with the flash on. might see something

you can use a cell phone to take pic or video , we also use mirrors and a flashlight , signs are what the previous post said , cups only last a week or two before leaking again , dirty water in box , screeching noises from sand and small aggregate getting past the lips of cups , as far as flipping goes , I do not think once they're worn out that it is really worth it to flip .

I got new pumping cylinders from alliance 2 years ago for my 99 34x. not worth flipping for the price. They are working with the same cups 2 years later

I got new pumping cylinders from alliance 2 years ago for my 99 34x. not worth flipping for the price. They are working with the same cups 2 years later

Anyone remember that video of that pump somehere in Africa or something where the cups where so worn out that the waterbox was running over with pure concrete? I can't find it anymore.. That was crazy :-o

I remember, it surfaces every few months on Facebook. The whining coming from those cups and that hyd system was terrible.

Evidentemente, la apariencia de cemento o arena en la caja de agua es signo de desgaste o pistones de goma o de cilindros de bombeo o de ambos. El desgaste de los cilindros QUE HE REEMPLAZADO se evidencio facilmente incluso con rayaduras palpables. GRACIASi