power steering whine

[woo003]

hi, my David Brown is experiencing an issue with the power steering. it whines all the time when running. and sometimes squeals when you turn. I have replaced the oil in it. bled the system (which makes the noise go away), but it almost instantly comes back. the steering wheel is relatively smooth and easy to turn. with a small amount of vibration or juddering when you turn. I don't know what to approach next. there is no leaks on the high pressure lines. I am wondering if there is an air leak in one of the low pressure lines? if so how would I go about finding the source of the leak. I hope I don't have to replace the pump.
any help would be appreciated.

thanks.

 

[olgentdc]

my guess is a belt making noise , which is doubtful , or ,a bearing whine . if it were mine i would use Lucas power steering enhancer. That might help .

 

[kenbob]

This may not apply to your tractor. My Dodge mini van did that. There were screens going into the pump that were to protect the pump. The rubber hoses deteriorate over time. The particles plug the screens. Supposedly many folks got sucked in for a new pump when what they needed was new rubber lines and the screens cleaned.

 

[Frank(Mi.)]

Usually is indicative of air getting into the system. I've seen two cars do that. One the owner let the fluid get too low. I fixed that by filling the resevoir and then turning the wheel lock to lock a half dozen times with engine running in park and the front tires jacked up just off the ground. The other actually blew a small hole in the return line. Replaced the line, refilled and did the same process with steering wheel as above. Neither car was mine but they still are going fine after a couple years.

 

[kenbob]

I should clarify: In my case the whine occured only when you turned the wheel. No whine from the pump when not under load.

 

[RGMartin]

What model?