Bush Hog BH750 Pump leaks

Gergory · Jan 1, 2020

Bush Hog BH750 backhoe, Just bought it used a month ago and used it for the first time yesterday. When I use any of the levers, the pump leaks out of the bottom of the pump (between the two hoses that connect to the pump). I forgot to bleed it but it's a closed unit so I'm not sure it needs to be. Does it matter if the torque forks are up or down? Right now they are up.

dfkrug · Jan 1, 2020

Sorry to hear your pump is leaking. It may be fixable, if you can locate the proper seals. Maybe you should convert to tractor hydraulics.

Your anti-spin fork on the pump works the same way, regardless of how it is installed. If you rotate your pump around to place the fork up instead of down, wont that add a twist or 2 to the IN and OUT hoses? Unless you remount the fork to the pump and keep the pump in the same position.

Have you checked your hyd fluid for water? These hoes with PTO pumps/tanks often get water vapor entering the vent and adding water to the fluid.

What do you mean by bleeding?

Gergory · Jan 1, 2020

Thanks for the reply dfkrug
I may need to remove the backhoe from the tractor and get a better look at the pump to see exactly where the leak is and thought someone have a quick fix. Maybe tomorrow I can take it off the tractor. I kind of figured the fork position didn't matter but thought there may be a breather hole or something but probably not. The oil looks clear not milky and it was just changed before it was sold to my neighbor which in turn sold it to be because it was too big for his tractor. Instructions says to bleed the air by extending all pistons a few times get the air out of the hoses.

Gergory · Jan 2, 2020

How can I tell if the pump is 6 or 8 GPM?

dfkrug · Jan 2, 2020

Gergory said:
How can I tell if the pump is 6 or 8 GPM?

3 ways:

>decode maker mark code on pump, if evident.

>Run the pump at known RPM and put the outlet hose into a bucket. Time the run and measure the output.

>Take apart the pump and measure the internal parts to determine pump volume

There is no need to manually bleed air out of the cylinders of the hoe.