Hello everyone,

I have a Putzmeister Pumi concrete pump and the waterbox is getting hydraulic oil in it, would  I be right in saying that the piston hydraulic ram seals and gone and need replacing?

Because it is pumi pump and has no access to the inside of waterbox like most concrete pumps,( you can not see the rams, they have a sealed waterbox) does anyone know how best to access these seals so I can replace them?

Thanks for any help or info...

Any ideas anyone? 

From the looks of the diagrams, the pistons come out through the hopper.  Some trailer pumps are done this way.   You should be able to pull the end bolts, pull the delivery piston and guide ring off, and remove the centre bolts to get the piston carrier out.   To put them back in, just reverse the order.  Use lots of grease to get the delivery piston tapped into the barrel and onto the carrier.  

There's no dog bone in a PUMI - the piston is connected direct to the drive cylinder. 

There's a procedure for this in the HARDCOPY of the putz manuals (not on CD usually).   In the north american manuals for pumps with a dogbone its Machine card 06-009 (page wk_06_009_9909). 

Give putz a call - I'm sure there's a procedure specific to the PUMI.

I uploaded some photos - hopefully they appear.

AND..I just noticed that your question was for seals, not pistons.....looks like you'll have to pull the drive cylinders and change the seals on the bench.   You'll have to pull the mud cups out first....

You are correct that the ram seals could be at fault, just wondering how much oil in the water box are you getting?  The tk 70's that have ran have always had a little oil in the water box after a long day. If you are seeing less then 3-4 tablespoons of oil after 60+ yards it might not be a real problem.

putzs have oilers on the delivery pistons to help lubricate them so a little oil will be in the box , but if it is excessive , it looks like on that machine it will be a major mechanical job.

Thanks  for the help, really appreciated