Hi

My brother s 32m schwing 1200 1998 is pumping to slow.Since we bought two years ago,we change the manuel concrete volume controle and still the pump doesnt pump full speed.Volume controle on the remote and on the rear panel work fine.Wide open we feel like it pumps half the speed it should.I don t know if it something to do with it s doesn t pump smooth, the concrete flow is not steady as a result of the boom bouncing so he has to slow down and play with the trottle to find the right spot.He end up pumping pretty slow.Any advices!!!???

you need to find out, if the diff. cylinders are plumped on rod side or piston side, if plumped on piston side, the loop line, that connects the cylinders, is at the water box; if this is the case you should get somewhere around 15-16 strokes per minute as max output; on rodside you will see around 25-26 strokes; check that before you start messing with the hydraulic pumps; you can change the plumbing around, if you need to

!-888- SCHWING ask for the service dept.

plug the hose going to x1 ports on both pumps, shuld go to full volume @26 strokes /min. if not you have pump problems.

Pumping slower you make more money and its easyer on your pump kit.

gboom is right.  check to see if you're plumbed for piston side or rod side pumping.  I run this same pump.  About having to play with the throttle to find the right spot, I always do as well.  Just depends on the mix, setup,and job where the throttle and volume need to be set.  Sometimes I pump at 1200 rpm and sometimes 1450.  Doesn't seem like much of a difference, but 250 rpm can be a night and day difference with that pump kit.

Check the cutting ring on the Rock valve. If it is worn or not opening all the way it will pump slow because it can't suck in the mud. Very important it will loose cream on each stroke and cause double the friction to push it through the pipe which will cause boom bounce.