I have a question on the Schwing P88.  I am using it to pump ICF's.  It pumped the footing great.  After we were don't we opened it up to clean it all out.  My dad decided to start it up while it was open so the cylinders would push out anything inside or them.  The largest cylinders case came forward along with pison. 

Now when we try to run it it seems to lock up and the arm on the second piston stays up in the air at times.  When it does come down it comes down hard and it very noisy. 

I will see if I can add a video tomorrow to help.

-Isaiah

That would be great!  I did take off the cover plate to look at the spring to see if it was broke ot needed more tention.  It seemed fine but I didn't have anything to compare it too.  If I reach in the large cylinder and coat it with grease it will not catch on the compression stroke, but after it runs for a bit, it will get stuck again with the arm up.  Its raining now, but I plan on firing it up and adding a video so you can get a better understanding of what it is doing.  Thank you very much for your input so far.

-Isaiah

The box that holds the spring and piston casing?  We just bought the pump for this job.  When i took off the plate it was dry inside.  It didn't come with a manual.  It has grease zerks that go down into the box so I didn't think it would have to be filled with anything.

I'm pretty i need to replace the piston cup/seal on the 6" piston.  I attached pictures of the seal.  How easy is it to replace the seal?  Do I just remove the three nuts on the front end or is there more involved.  As is this the correct seal?

http://www.concreteequipmentinc.com/shop/viewitem.php?productid=492

The video is with vaseline around the cylinder wall.

The pictures are of the seal.

Once I added water to the piston the arm first got stuck in the upper possition.  Once I pressed down on it, it began to cycle again but would slam down.

Perfect.  My ball and seat look good.  The 6" cylinder looks good but haven't  checked the smaller cylinder.  Do you order our parts from Schwing or a different parts dealer?

The owner who had it before me said he was, "having trouble with the fuel pump so he just put in an inline 12v full pump from O'Reilleys".  Well that full pump worked when we last used it but isn't anymore so I just hooked back up the old stock one.  He wired the switch on the operating panel to the fuel pump.  So i'm not sure what the original reason the switch was there?  Remote?  

Maryville, Mo - Northwest Missouri

I got the 3 nuts off but am having a hard time removiing the plate.  Do I need a gear puller or something like it to get it off?

only reason it is stuck in the uper position is cuz there is no concrete in the hopper now have ya checked the seats? are they hevy or light? might just be the seats but also can be many others but let us know what ya have done in like a tune up to....

I  think your tension arm is worn. This is the arm in front of your spring. There is a oval hole in arm, the rod that the mud cup is conected to goes through the spring, and into the tension arm, and held in by a pin. When pumping this rod will travel back and forth through the tension arm and the pin will travel that oval hole. The hole in the tension arm that the rod goes though  has egg shaped it is keeping the rod from travel not letting the arm to ride on the lobe This is why it is slaping. All that you need to repair. Depending on how long it been runing this way. Some things to check  1 grease zerks on tension arm line may be broken. 2 rolling bearing (top large arm rides on the lobe) 3 spring could be broken 4 mud cup could be worn (could have flat spot ) You really need to take it a part. You might want to try looking on internet for a manual.