3930 power steering problems

jlbash1 · Aug 7, 2006

I have noticed the last few times i've use my '96 NH3930 that the power steering has been acting up. It is really bad at low RPM's, almost no assist at all. At higher RPM's, while mowing, it's not too bad, but if it try to turn quickly it tends to not keep up with me.

Does this sound like a dirty filter? I've never changed the filter or even know how at this point, I've only put about 50 hours on the tractor so far, it has abou 700 on it now.

I have checked the fluid level and it seems fine.

thanks in advance

jarrod

jlbash1 · Aug 10, 2006

Well I went by the NH dealer yesterday to buy a new filter and some fluid. I explained the problem I was having and got mixed opinions.

The service guy wasn't too optimistic that the filter would fix the problem, but I only have 700 hours on the tractor and these pumps usually last much longer. This power steering pump has been around since the mid '60's so they tell me. they aren't repairable, and they aren't cheap either. looking at about $700 for a new one.

The parts guy did mention a relief valve that could be shimmed possibly. Does anybody know anyting about these things. if the filter doesn't work I'll have to do something, I'd like to try shimming this valve, but don't know much about it.

I know someone around here has experience with these pumps, I bet Ford put them on lots of tractors over the years. I'm guessing a 4000 ford has the same or very similar pump.

jarrod

floridahay · Aug 10, 2006

I think that Ford used the same pump or it looked to be the same pump for many years. I have owned several Fords from a 67 4000 up to a 4630. The system was changed some when they went to the 30 series in about 1990 or so. It was at this time that they changed to a hydrostatic system instead of the power assisted system that they used for many years. Sorry I don't have any ideas on what is wrong with yours. I kind of doubt that changing the filter will help because I knew of people who never changed the filters in those things and they never had problems with them. Good luck anyway.

jlbash1 · Aug 11, 2006

Well I changed the filter last night, that was an akward thing to remove. I'm never lucky, but luck was with me last night. After the new filter was in and I added just over a quart of fluid to top it off, the steering worked like a charm!

I wish I had taken the filler cap off of the pump while the tractor was running before i changed the filter. You can see the fluid being pumped through the filter with the cap off. At least I could have visually compared the flow rate of the old and new filters.

I did notice that the fluid that came out of the pump was a red color, and the stuff I added was a clearish fluid, I guess this is just plain ol' hydraulic fluid? I know there are some fluids you shouldn't mix. Think there could be any issues in mixing these fluids?

Thanks

jinman · Aug 11, 2006

jlbash1 said:
I did notice that the fluid that came out of the pump was a red color, and the stuff I added was a clearish fluid, I guess this is just plain ol' hydraulic fluid? I know there are some fluids you shouldn't mix. Think there could be any issues in mixing these fluids?

Is it possible you had automatic transmission fluid in there before? Cars use ATF in the power steering and someone might have added it to your reservoir. I don't know of any NH hydraulic fluid that is reddish. However, Skydrol that is used in lots of aircraft hydraulic systems is purple, but that's a stretch to think that someone put Skydrol in your power steering reservoir.

dgl24087 · Aug 12, 2006

Aren't there red power steering fluids? Possible that a previous owner had put PS fluid in instead of hydraulic fluid?

jlbash1 · Aug 14, 2006

i'm not sure what the fluid was before, but who knows what the last guy did. i think i'll drain the fluid a few more times to get the old stuff out. luckily it only holds 2.5 quarts so it shouldn't be too costly to flush out.

at least the steering is working well now. hopefully there was no damage to the pump, like i said these things aren't cheap.

thanks for the input

jarrod

Soundguy · Aug 14, 2006

jlbash1 said:
i'm not sure what the fluid was before, but who knows what the last guy did. i think i'll drain the fluid a few more times to get the old stuff out. luckily it only holds 2.5 quarts so it shouldn't be too costly to flush out.

at least the steering is working well now. hopefully there was no damage to the pump, like i said these things aren't cheap.

thanks for the input

jarrod

Most likely someone put ATF or PS fluid in it... Won't hurt it. Though i run UTF in mine. Someone could have put some UTF that was colored red.. I think it was hytran? that was red?

Glad the filter helped. Those 'assist' systems weren't powerfull to begin with.. if it was starved.. then it was probably a dog.

The fact that it steered better at higher rpm than at lower rpm should have been a clue to the Nh tech that it was -NOT- a relief valve issue.. but was rather a volume issue... Volume issues could be related to pump flow ( wear), or, pump flow ( restriction ).

If the pump was going into relief at low rpm.. ( not turning good ).. then at high rpm.. it should have been the same.. or worse.. but not better.

Soundguy