I run a 2002 42 Meter concrete pump and I'm having a problem with the stroke. Just wanted some advice on what you think may be the problem.

When pumping, I'll have a full stream no boom bounce. I stop, turn the pump off, hit my airbag switch to keep the boom full.

When I want to start pumping again, I release the airbag hit the pump forward switch and it just splatters for like 10 - 15 seconds, then it becomes a full stream again. If you watch the cylinders, they move very slowly at first then start to go at normal speed again. When pulling the ball back, If volume is anywhere from 1-3.5 I've timed the stroke and it was 1 stroke per minute. Once I turn it to 4, it starts to move the cylinders, but they skip while they are moving (Kind of hard to explain in text format).. I was told that the stroke limiter coil is probably bad, but It seems like there is absolutely no difference in putting the pump in Pressure control, or Normal control at the quarter turn valve.

On the 34 meter pump I ran, when I would stop pumping, then go to start again once i opened the airbag and hit the pump switch it would maintain a full stream no matter what.

anyone have any idea of what the heck is wrong here?

The company paid for people to go to school to know how to diagnose these issues. You been fighting with this issue for quite a bit of time..I believe it's due time to get it fixed. Sounds to me like there is a pin inside a valve with the o rings chewed off it or something. Make a point to call Schwing service tech in bear lake and explain the issue to him. He will walk you through the correct diagnosis. A machine with issues happens ..you deal with it and get it fixed before it becomes a distraction from the safety of the contractors guys as well as yourself. If you get a distraction..then something else goes ..well pretty soon you are overwhelmed..domino effect...seasoned operator or not..a machine is designed to operate properly..gotta make money..but sure as hell safety is priority number one..looking good..ease of operation and professionalism gets the customer to call you back for the next one . I hope someone here can help..if not make the call Monday ..happy pumping

There are a few things, that could be the culprit, but it sounds like the stroke limiter is on iits way out. I dont know if you have gauges that you can hook up, that would tell you exaclty what the your pressure readings are. If you dont, get the cartridge for the output side of the stroke limiter and a new electrcial coil. That will probably get you where you need to be.

Does it matter what your temp is or is it all the time. Go to your stroke limiter cartridge and unplig the coil, take the acorn nut off the top and take an allen wrench and screw it in until you reach the desired stroke, if that fixes it, obviously it's your coil, if not, maybe the cartridge. If that doesn't fix it, there is a block up on the brain of the pump that has a cap on one end held by 4 allen bolts, pull it off (there is a spring that will come out, just take your time and pay attention it's easy), there is a cylinder in there that you can pull out that has a set of scrapers and an o-ring on each end, that maybe your problem. I'm saying this thinking that your filters and oil are good? Also, see if it's doing it all the time or just at temp, if the o-rings are bad, it may also cause it to run warmer oil temp sometimes.

no temp doesn't matter .. it does it all the time. on a 200+y job at 70degree ambient temp it runs about 47c . the hoplink is broke for remote lcd readout so only reference is back panel. ill check out what may be the issue sometime this week if I get a shop day

It's Awsome you guys chimed in with your suggestions. That's what concretepumping.com should be for..operators helping operators, the stroke limiter has been mentioned before but without one to swap out it is impossible to know. We have issues with the supply chain, attitudes on steroids I guess you can say..bad attitudes, but with all the knowledge here, it is possible to get some clues, some understanding of what the entire issue might be without the issues associated with our current resources. I could play with the problem for a long time or seek people who might of had a similar situation without them flaring their nose at me, in my experience problems snowball and lead to downtime when not addressed in a timely fashion. Most of us here are professionals, we don't all have the same knowledge or experiences..so the message board is great for brainstorming. I can ripp into anything , make a few calls and get it fixed..but in the meantime the machine is down and not making money. There are people who don't like me for being intense about fixing things, and bosses who make excuses for them. Please get over yourself I have much to give, I have a desire to remain professional, minimize downtime, and streamline maintenance, thereby I have more uptime to do what's important..more jobs at less cost, higher quality of service, and most importantly..safety to both operator and crew. 

Once more I say thank you for giving mr Perkins some options to understand what he might have to look into to resolve this issue. 

The valve assembly that sits in the brain behind the "Normal Pressure / Pressure Control" Hand valve/block assembly was bad. The inner body was scored up, and the outer body was missing the nylon locking rings that seal it up so oil was bypassing causing a pressure issue. The other issue was the stroke limiter was changed at one time, but it was never adjusted so the mechanic helped me adjust that as well. The accumulator bag was blown, or low on charge too. We swapped it out with a known good one. It definitely strokes better now at least... I'll find out tomorrow if my stroke is better though!

xforce was right

thanks buddy :)

Your welcome! I'd thought about low accumulater nitro but didn't seem to be your major problem. Glad we could help and your up and running!!