740 Power steering

duckrock · Jan 29, 2013

When I bought my 740 the power steering pump and pressure hose were in a five gallon bucket. The hose was cracked and taped back together. No idea exactly why it was removed or how long it has been off. Today I had a hose made and hooked everything back up. Something just isn"t right with power steering connected. There is some residue on the cylinder rod when it is extended outside cylinder but not bad. The main problem is that the steering doesn"t seem to travel through the full left to right range without becoming tight or binding. The hydraulics are making it harder to steer. Seems worst when at outer limits on both left and right side. Anyone have any ideas what might cause this or what I should be looking for?

Thanks.

showcrop · Jan 29, 2013

showcrop · Jan 29, 2013

I believe that most are removed due to leaking cylinder. They will usually leak because dirt accumulates on the underside and starts to wear the chrome at mid point. then it gets slowly worse until it gets pitted and ruins the seal repair is expensive because it needs to go to a good shop where they cut off the back end, reseal and weld it back together. Yours sounds like a problem with the control valve at the front end. It sounds like it may be bound with hardened grease, so a partial dis-assembly may be needed to free up the piston inside that needs to shuttle freely back and forth. Another possibility is the grease fitting on the back of the control valve. The fitting needs to be much shorter reach than a standard grease fitting or it will impinge on the piston keeping it from moving. I recently had one that was leaking at the main cylinder just a little, so I smoothed up the rough part with emery cloth, applied phosphoric acid to get at the rust, then applied a little epoxy, then smoothed it up real nice. Haven't seen any drip since.

souNdguy · Jan 29, 2013

post a pic of your setup. specifically the mount bracket onthe rail, the draglink arm and the valve, plus the front sector arm into the steering pedistal.

duckrock · Jan 30, 2013

Hope these pictures help with figuring out my steering problems.

showcrop · Jan 30, 2013

you have lost a lot of the chrome on the rod. It will require a new rod to fix it but you can stop it temporarily with the procedure that I described. Have you checked the grease fitting yet?

This is one of my three Ford 4 cyl row crops.

duckrock · Jan 30, 2013

Thats a nice tractor. Could air in the system be a problem?
On my last picture it looks like the cylinder goes inside a
piece that could be screwed or pressed into the outer
cylinder case. There is a ring all the way around like it is two
pieces. The front end looks like it was welded before. It is a
good weld so if it isnt original someone knew what they were
doing. I dont have any others to compare to, so I dont know
if the ends are factory or indication of past repairs.

showcrop · Jan 30, 2013

(quoted from post at 06:52:01 01/30/13) Thats a nice tractor. Could air in the system be a problem?
On my last picture it looks like the cylinder goes inside a
piece that could be screwed or pressed into the outer
cylinder case. There is a ring all the way around like it is two
pieces. The front end looks like it was welded before. It is a
good weld so if it isnt original someone knew what they were
doing. I dont have any others to compare to, so I dont know
if the ends are factory or indication of past repairs.

The cylinder is assembled as you describe. Very unlikely that air could be trapped because the vented reservoir is directly above the cylinder.You could not trap air in there if you wanted to. Have you checked the grease fitting yet? I believe, as I stated before, that you problem is that the piston in the control valve is being kept from moving freely by hardened grease or a too long grease fitting or both.

duckrock · Feb 3, 2013

I was able to get out and mess with the tractor yesterday. I
had not done anything come to it but it seemed to be
working better. I pulled the grease fitting anyway and didnt
notice anything come out. Grease fitting went all the way
back in and everything seemed to be working okay. The
cylinder is leaking some. For now Im just going to wait and
just see how bad it is. Thanks for all the help.

740 Power steering

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