Got a problem!

When im pumping 40 mpa quick into a slab the right hand piston gets a fultter at last half a meter of its stroke ....

The only thing i could think of is the proximety switch is a little out ...

has anyone had this problem ??

If you have an accumulator circuit it could be trapped air.Sometimes air gets trapped in a cylinder because of rocky mixes and it shifts too fast to burp it. Next time it happens wait until that cylinder's next stroke finishes and reverse it two strokes and see if that cures the problem.

Very vague details, more specific details can possibly help.

Q1. Is that only with 40mpa at full revs what about without revs? Is the pump labouring when it does this?

Q2. what about lower strength concrete at full rpm?

Q3. How high is your pressure guage when this happens, is there a fluctuation in hyd pressure? i.e Does the hydraulic pressure guage change go higher or the same when this happens?

Q4. When the right drive cyl side flutters does the left side flutter too?

A problem in a proxy switch shouldn't only be evident in 40mpa crete.

Some 40MPA mixs in Melbourne are shocking esp. the post tension mixes.

check your wear plate, and cutting ring, may have a chunk out on one side, are you loosing any wash box water?  Check the mix , AEA (air entrainer) will cause something similar.

is the s valve porting properly on the right?

Sorry , will probably think of a few more in a mo!!!

Given the little info, I think Murf is right.  Doesn't sound like the hydraulic/electrical system, but rather an issue with how the concrete is actually flowing.  This is what I've found is usually the case when it's happening at the end of the stroke (because the cup is at the bottom and concrete gets jammed up).  Just check the wear on cylinders where they meet the intermediate ring, check the wear plate, s-tube, and thrust ring behind cutting ring.

LOL sry guys , had a few too many last night thats all i could manage to type !

Wear ring and plate are good!

only with 40mpa pt

not happening at low revs only at 1300 and above flow at three quaters or above

the hyd guage shows no fluctuation when it happens

the S tube is porting fine

guage is any were above 90 bar

new piston caps.

Seroiusly there is nothing i can see that could be causing the problem everything is good ...

40 mpa .. you use a diferent system to us , what is this?, when it flutters , you mean stop  and not pressure up????

40mpa is the same as C30/B40 or something, same classification, different names.

Murf it doesnt stop or block it doest realy even slow down.

the concrete shutters through the pipes and the hose , you can see the concrete fluttering out the hose you can hear it in the pipes but the machine doesnt change tune or make any funny noises , its not labouring the guages arnt showing it the wear ring plate and seals are good the pipeline is 4 k old , the machine is in imaculate condition ...

I still think its a proxy switch thats out of ajustment ...

I just thought that someone might have had this problem.

If you are running a closed loop system, it is most likely more to do with the neutral setting on your main oil pump. Another item to check is your "loop flushing valve"

we had a cifa 31/5 which did something similar, but on both strokes or when it felt like it , narrowed it down to the output speed control. it was only on loan so we never ended up fixing it!!!!  think your gonna end up watchin that one for a while with your ar... tighten up every time it does it!!!!!!!!