The Stovebolt Site Forums The Parking Lot Big Bolts Hydraulic Pump / Valve Questions

I've got a Knapheid grain bed on my 1958 1 ton, with a non-original hoist set up. It's got twin telescopic cylinders (3.5" Glenco's) that likely came from a 2 ton. The pump (Gresen vane pump) and valve (unknown manufacturer) appear to be in working order. I cleaned them up and they look OK. The pump turns quite easily with fingers. I think these may have been original to the Knapheide hoist.

I just stumbled across a free gear pump / valve set up that came off a fairly modern truck (2+ ton truck). It looks to be of superior quality to the old pump / valve that I've got. It would also install much easier. I'd like to use it if I can.

The only manufacturer symbol I can find on the pump is a "W" insided a square. The valve has a "T" inside a triangle. Sorry I don't have pictures yet. It is very hard to turn this pump with my fingers.

Anybody know of a reason why I can't use this newer gear pump? Can the PTO off my SM420 handle the torque this pump may take to turn? Know who the maker of the pump and valve is? Should it be easier to turn the pump? Should I rebuild the pump and valve?

As always, Thanks!

The symbols you describe unfortunately meannothing to me however Imight recognise the make with photos of it.

Here is what I do know;

Glencoe did use Gresen pumps that had an integral valve assembly and they were known for short life. I always had several in the used parts area of my shop. And as a vane pump they did turn quite easily. Glencoe was a manufactuerer in IL but had no relationship to Knapheide, also an IL manufacturer. They may have been sold by the same equipment seller/installer. That is all. If the cylinders are 3.5" they are too large for your 1 ton and are likely to have far too much stroke but still works of course. The Gresen pump is about 8-12 GPM as I recall. The used pump needs to be in the same range. If it is a gear pump use this rule of thumb: 10 GPM rer inch of gear width @ 1000 RPM. Gear pumps are much more difficult to turn so don't let that bother you. Your PTO will turn it just fine unless it is a huge pump which I doubt.

Do you know the condition of the "new" used pump or could you just be replacing one worn unit with another?

Gresen vane pumps are easily rebuilt and that is what I would do. Replacing it with another brand/typw will cause installation problems that you don't need.