D14 power steering install

Purchased a factory power steering unit and  installed it.  The steering wheel will only turn if I turn the wheel with  arm strength. The steering wheel is easier to turn with the engine off. Could it be a bad steering valve(motor) which is on the left side  when sitting on the tractor.  We do have the lines hooked up correct.  

Edited by Steve(SEMN) - 27 Feb 2010 at 11:45am

Check to be sure that the steering input shaft is free to float  in and out of the valve housing.  This end play is what actuates the valve spool.  If the splined shaft that comes forward from the universal joint is too long or bound up in the coupling, it could cause a problem like you describe.  The reason I say this, is that there are two different length shafts. Perhaps you have modified the longer one from your manual setup by shortening it to fit. (do-able, but the length is important.)  Also check to be sure someone hasn't got the cylinder lines mixed up at the valve. That's not likely unless the lines have been replaced with homemade versions.  Basically just what tbran said....

I think Brett has something with the free play on the shaft splines. The Steering motor also acts like a valve and has to center itself. If it is bound one way or the other by the manuel side of the system it will keep sending oil to the cylinder.

Well, if the lines are hooked up right and the valve spool is free to move, my next move would be to check for fluid flow.  Try cracking the small line that runs from the back of the pump to the valve with the engine running.  If there is no pressure or flow there, check for obstructions in the large suction line or a sheared key in the pump.  The Barnes pumps are bad for wearing out the woodruff keys and keyways in the shaft and gears.  I put probably 40 hours of machine shop time into rebuilding mine with new parts that I made.

Update on the power steering.I have good news. Brett Phillips was right about the spool valve needing to float freely in and out. The first one did not move. Examined a second control valve body and noticed that the spool valve moved  1/4  inch or so by hand.  Installed this second valve last night and I now have one finger power steering. Do these valves get stuck on working tractors or play out in time from sitting? Does anyone rebuild them? Thanks for all your input guys.

Ok - finished a stem to stern rebuild on a D14 that was headed to the salvage yard. New paint, and it looks cool. It was gushing oil from anywhere there was oil, so now complete. Except,,, one oil leak. After a few weeks of prodding, the seal on the rear of the steering control motor leaks. It isn't the seal. Replaced the original when i rebuilt the power steering unit , and when the ONLY leak on the tractor appeared after the overhaul, i pulled the front support, and replaced the seal again. still leaks. only hint i have that something is not right is a slight delay when the tractor is still and i turn from right to left. Very minor hitch before smooth operation. I have spent a ton of time trying to figure this one out. Now i'm wondering if i may have done something wrong on the overhaul of the steering control motor (which is really just replacing o-rings). For those that chimed in on this thread, does anyone have any ideas? Facing reality that i will have to pull the front support off again (3rd. time),,,,, Thanks to all.