PTO Hydraulic Pump

pmantis · Sep 18, 2007

Hi everyone.

I'm looking at using a hydraulic t-post driver / jack hammer and it needs 5.3 gpm and no more than 1300 psi.

It seems on the used tractors in general, the gpm / psi are not published anywhere, but on the newer tractors, anything over 18/21hp has too much pressure and flow rate.

So, I'm thinking / hoping a pto hydraulic pump might do the trick.

So, where can I find a pto hydraulic pump with those specs. I'v sure searched the Internet but haven't found one yet.

QUESTION 2: If that doesn't work, how much should it cost to get the tractor hydraulics split to put in an external hydraulics? And, to measure the pressure / gpm coming out so I know what I need to get it down to what is needed. (There is a flow divider I can get if needed)

Thanks much!

Elissa

6sunset6 · Sep 18, 2007

For less flow run less rpm. For less pressure you can cross connect a pressure relief valve. Don't touch the tractor valve. Connect a relief valve across the input and output to the hammer. what ever pressure is developed over the setting will go over the relief valve back to the tank.
You may also get less pressure at less flow . Ratings are usually at some given rpm. Simple test hook up the unit and with engine at idle see if it works. Crank up rpms until it works. Depends on the tractor but most of the 20-30 HP flows are around 7 . So maybe 1000 rpm would run it.
I guess my point is you can always get less out of a system. Relief valve and flow restictor if you have to.

Mith · Sep 18, 2007

You may also get less pressure at less flow

As I understand it, max pressure is constant at any flow. It'll keep building up pressure till the relief valve opens, or if you are on idle it might stall if there isnt enough power to build the pressure.

Elissa, connecting a relief valve across the hammer will limit to the pressure to what you set the relief valve to, in this case 1300psi. Drop the revs on your tractor to lower the flow. You can get both a pressure guage and a flow meter to keep an eye on the hydraulics into the hammer.