Hey i got a problem with 3rd section cylinder is very weak when it gets to centre point of lifting point it was leaking abit extrenally so i figured it maybe was leaking internally as well so i repacked the whole cylinder and is still the same only now when i get concrete in boom it wont hardly lift it at centre point and pressure is just under 300 bar off main control block when it gets to centre point then drops down to 150bar when the boom is in a easier posiston to fold could this be a holding valve issue?the boom doesnt creep at all even before i packed it any info would be great thanks

definitely a holding valve issue, there should be two,get with putz they can guide you to the correct one.

you have oviously messed with boom cylinder before ,the only thing I need to stress is SAFETY when messing with these.The problem I have is did you repack the cylender? or a Hydraulic cylinder shop .I question the tube ,does it have a dent or distortion in the center as you have said when it gets to the middle it has a problem .a shop can mic the tube from top to bottom to tell if it is true .the mono blocks are not something to mess with also the settings are not adjustable .Please contact Putzmeister about these valves.they set them to the boom spec for your specific unit make sure you have the serial # when you call .

Could try pressuring it out at it's full extention hold pressure to it, of course make sure no one is under it. A putz call is important. Had a few holding valve issues also replaced then same problem, dirt in oil blah blah, we would hold pressure at full extention, but this sounds different.

yes i have repacked quite a few cylinders before this one came apart easy and went together good too.ive called putz service and they dont seem to know what the problem would be either.The boom doesnt creep at all in any posistion i even took the elbow off the swivel thinking maybe the boom pipe may have been too long but thats not the case either.

left that out make sure you bottom out both ways.

Start with the easy stuff:

1 Has anybody messed with your boom settings (some operators can be cruel)

2 Try your hardwire

3 On each boom lever there are set screws that you can wind in or out check to make sure one hasn't wound itself in.

4 When you are standing by the boom controls actvate your 3rd do you hear oil bypassing.

5 Do you have a pinched hose in the turret.

6 At the boom controls switchout hydraulic lines for your 2nd or fourth does this change anything. If it does then your problem is not in the cylinder,  it is probably in the control block  something is blocking an orifice or pressure releif or check valve.

Have fun it can be frustrating.

Honestly I am concerned about a couple things with the story.

I think I have recieved calls from several people about your unit.

Did you have the cylinder rod and bore chedked for true? Why were the packings bad? Could the rod be bent?

I also would question a mechanical issue, disconect the pipeline at the joint and operate the arm looking for distortion in rotation, are all the joint pins taking grease? Has it passed a Boom Inspection?

This could be a symptom of a larger issue.

I do not want to scare you but caution you toward the safe side thanks for looking and asking for help.

PMA CSG 1-800-890-0269

you can also contact me if you like.

TT

Turns out it was the charge side holding valve put a new one on and it works like new again thanks again for all the tips and help!

Good to know,we have this problem with our two 38Zs.