F 40 power steering problems

[Tom/Idaho]

Tractor originaly had spindle bearing/bushing problem. Fixed that but power steering still will not work. P/S is similar to a MH 50 and does not bind anywhere during rotation of steering wheel.
1. Have 1100# pressure at pump at 2000 RPM
new filter and fluid (type A)
2. replaced bushings in P/S pedistal
3. Dissassembled P/S valve. Appears to be okay. Could not see any obvious damage.
4. Tested cylinder with air and it extrends and retracts
5. Bled air and adjusted control valve per service manual.
Power steering still will not work. The valve inside the control valve does not appear to move much. How far is it supposed to move?
Any assistance is greatly appreciated.
Thanks, Tom/Idaho

 

[chuck41]

Tom, Have you tried to adj that little turnbuckle
while tractor is running, just a bit at a time,
back or forth as someone is at the wheel to see
when it is right. Chuck

 

[Tom/Idaho]

I did try that before I replaced the bushings, which were pretty loose. I will try it again tomorrow now that it is pretty snug.
I have tried to pull the turnbuckle while someone turned the wheel. It did"nt make any differencce as the valve hardly moves, but then again I don"t know how much it is supposed to move. It"s a pretty stiff spring.
I found a used valve on the internet and he wants $150.00 for it. Thanks again for any and all help, Tom/Idaho

 

[miner09]

Will it turn with wheels off the ground? Also did you give bushings enough clearance? I rebuilt mine and I had to ream bushings to right spec's. Check and see if tie rod's are not hitting underneath where main arm bolts to pedestal.If arm is not up tight tie rod's will hit housing.

 

[Eric in IL]

Do you have power assist in one direction only , or neither direction ?

If one direction only , check the fit of the pins at each end of the turnbuckle. They need to be a snug fit .

If neither direction , make sure the big set screw which controls the stroke length of the valve is adjusted per your service manual. If it is , try backing it out some more to help you troubleshoot the situation.

The valve doesn't require much movement to work but it does have to have enough. New bushings in the pedestal is a great asset in eliminating slop in the system. Wear at the turnbuckle pins is another high suspect of no or one-way power assist .

 

[Tom/Idaho]

Yes it will turn fairly easy with the wheels off the ground. Does not turn any easier when running.
I replaced two bushings and used a hone on both. The pedistal turns very easy unhooked.
The main arm is up close to the pedistal and the tie rods are not hindered in any way.
Other than something that is broken in the valve, is there some way to test it?
I used to have a 65 and I know what their power steering is like. This one is not there YET.
Thanks again, Tom/Idaho

 

[Tom/Idaho]

I have no power assist at all.
I adjusted the big set screw that controls the valve travel per the manual.
The manual says to back it out seven full turns after bottoming out. I will try backing it out further tomorrow.
I replaced the bad bushings in the pedistal and there is not any slop in the pedistal movement. I don"nt think there is any play in the turnbuckle, but I will check further in the morning. Thanks again, Tom/Idaho

 

[Eric in IL]

Boy Tom, sounds to me like you got most of the bases covered. It has been awhile, but I think the hyd. hoses are different sizes and therefore can't be reversed. Pardon me for going into wild guess mode, if you checked pressure right at the pump I guess it may be possible to have a hose that has separated/collapsed internally shutting off flow to the cylinder ??

With the work you have done on the valve I don't suspect it to be the problem but it is certainly possible.

Good luck, I'm sure you'll find the culprit. Hope you will post back and let us know what fixes the problem.

 

[eds40]

Speaking of the power steering adjustment turnbuckle, would anyone know someone who would have a good used one they would sell? Someone "fixed" mine, now I'm going to put it back as it was. Thank you.