The one problem with the b7800 was the fact it only had one hydraulic output. When I only had the loader mounted it was fine, once the backhoe was mounted everything slowed down. There is simply to much restriction in the system. Not only feeding the backhoe with flow but what’s worse is exhausting the extra fluid when cylinders are retracted. Yes the tractor pump is over 6gpm but I know I’m not getting it through the control valve.
I wasn’t entirely sure until I tried a friends l3901 with the his bh77 fed from a rear hydraulic output. It’s twice as fast and the cylinders run much cooler.
I’ve put a lot of thought and research into my plan of have a separate system just for the backhoe and then returning the loader circuit back to the stock plumbing.
Thank to everyone for the advise.
Late to the party, but I see you have a B7800, which for practical purposes is identical to my B2910.
I also see you are not the OP but the thread has moved in your direction.
Dan mentioned you are planning to use the mid PTO for the hydraulic pump to be powering the backhoe? I though the B7800 did not have a mid PTO.
Anyway, you might look at the backhoe that came standard with the B2910/7800. I have one. Uses a PTO pump. Is faster than I want at 2000 RPM. I usually run at 1800 RPM max and am happy with the speed.
Never an issue with heat or anything. I think if you would check the specs for the BL4690A backhoe you might get a starting point for what you need for the backhoe you are using. Granted you would need to compare cylinder size to get an idea of speed difference for a given flow rate.
Just seems to me that it is all about getting the correct flow rate for the speed you desire. Heat? From where I sit you must be super human if you are working at such speed to be heating your cylinders excessively on the backhoe with normal use.
I have used mine a lot over the years, and have no argument against anybody claiming I am abnormally slow...and therefore not generating much heat in the system...
