4690 BH pump kit

MChalkley · Apr 17, 2000

The setups I mentioned do not require a reservoir on the backhoe (except the PTO pump, of course), even though the backhoe (Bradco 609) on my tractor (L4310HST) is the largest you're likely going to find on a compact utility tractor. I'm not sure what you're talking about when you use the term "excess fluid".

Contamination is an issue, of course, but in my case I have a number of 3-point implements that use the hydraulics anyway, so I'm used to it. It's just a matter of keeping the fittings clean. That's what filters are for. I'm not trying to be smart, but to me it's kinda like not using the tractor because you'll wear the engine out. That's what I bought it for. I've got all that hydraulic flow and pressure for a reason: to do work - and you can bet I'm going to get my money's worth out of it. The Bradco backhoe has its own filters, as well, so it's protected and helps protect the tractor, too, for that matter.

PeteF · Apr 17, 2000

Mark,
The excess fluid I was concerned about is that volume of fluid that must be "available" in the worst case combination of cylinder positions, or "stored" in the opposite situation. The 2710 holds a total of ~ 3 gallons of fluid (of which only a part is available), the 4690 hoe holds about the same volume in its system/resovoir.

The 2710 has about 9.5 gal/min flow capability but I'm not sure how much is really available in the power beyond port accessable at the rear of the differential case. I don't know the output of the PTO pump.

I am OK with the fittings issue, but as a choice of systems (not including the frame/3-point issue), the PTO pump seems a good approach for me (I have a mid mount mower). If I did not have a mid mount mower and the need for one, I would have a frame mount hoe.

Pete

B2710/LA401/4690

MChalkley · Apr 17, 2000

Look at it this way: The cylinders can't move faster than the fluid pushed in (or pulled in and let out if gravity is the force actuating it). So there's no "excess". The backhoe is always "full", meaning there's always fluid in all the hoses, both ends of each cylinder, etc. When you connect, there's a little air introduced, but it's soon flushed to tank and that's that.

I'd never thought about the fact that mid-mount mowers preclude the posibility of a frame mount backhoe. When you get into the larger and heavier duty backhoes, a frame mount is necessary to prevent damage to the tractor.