# Hydraulics on a Ford MOdel 850 tractor



## Ed K (Oct 24, 2003)

Hydraulics on the tractor "hunt" or start sagging and require constant adjustment after the tractor warms up. Eventually after swinging a 6' diameter bushog for an hour or so the hydraulics will barely lift at all.

Couple of questions

1) Is the 6' mowerdeck too much for this tractor (I have the suspicion it is)

2) Does this sound like the seals, which to my knowledge have never been replaced, are leaking when the hydraulic fluid warms up? 

3) Or does this sound like the hydraulic pump needs some work. Ford dealer when discussing this over the phone, says he would try the seals first since the pump goes for about $800 bucks for parts alone

Your suggestions or input please

Thanks

Ed


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## Tractorman (Jun 8, 2004)

I knew a guy who had a early model 4000 that done the same thing I think his was a filter and seems like it may have been really hard to get to. I would check out the Ford forum at www.ytmag.com those guys are very sharp on old iron


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## uncle Will in In. (May 11, 2002)

Could it be that the hydraulic fluid is not the recommended weight for your Ford? I remember some of the older Fords I had took heavier fluid than other tractors that had the gear oil and hydraulic oil in the same compartment. The oil thins out as it gets hot. I think there is also a little draft control lever that may be turned the wrong way.


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## moopups (May 12, 2002)

Choose to explore the easy fixes first, 'O' rings in the control, filter replacement, fluid flushing, pressure adjustments, ect. I do not know if JD makes their own pumps, if not then you can trace the numbers back to the original manufacturer and pay about half of dealers cost at a franchize.


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## Guest (Jun 14, 2004)

If it ends up being the pump:

Do you have the vane style (first year of production) or the piston style of hyd pump? The vane pumps are easier (less $$$) to chuck & get a piston pump. The piston pumps have rebuild kits.

The vane pumps have a little selector on them, higher or lower, while the piston pumps are a more round body with no lever on them. You'll have to brush off the crud & oil.... 

Check www,valu-bilt.com for one source of these kits or whole pumps, there are many others. Your dealer will charge a mint....

The 'filter' is a mesh screen inside the rer end.

Probably the O rings is the way to start. Some labor, but less parts. It's possible the leathers or the piston itself is bad on the rear end lift inside I believe you can remove the cover by the pto control lever & watch to see for oil flowing past the piston.

When they came out, there was a thicker oil in them, close to 80/90. Now NH recommends their thinner 134 oil in everything Ford. Works well in a good tight rebuilt system, while the older thicker oil works better in an old loose system.....

Have you checked the oil for water in it, after 40 years of condensation & sitting outside, a lot of water can get in the rear end.

--->Paul


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## SteveD(TX) (May 14, 2002)

I also have a Ford 850. If the hydraulics are in good working order, a 6' brush hog should be no problem at all.


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## Ed K (Oct 24, 2003)

Uncle Will,

I've got the same gear oil and hydraulic oil setup

Unreg

I have the adjustment on my pump so I guess its vane type

All

Thanks


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