New Holland 2120 dead headed pump

[mike48130]

I believe the plunger is missing, it would be nice to see a picture of one. I didn't drop it...
I went out to double check and found it on the ground. Dang it. Glad you asked, I had everything laid out as I pulled it apart.I thought there was zero chance I dropped it. Going to put it in and test it with air again.

Well at least you found it. I try to take thing apart in a pan just for that reason, but doesn't always happen and I chase parts around the garage. Is there an adjustment procedure in the manual? I think it is open center until you turn the wheel and it directs oil to the cylinder. Put air on it and turn the shaft. see what happens.

 

[MrTea]

Is there an adjustment procedure in the manual? I think it is open center until you turn the wheel and it directs oil to the cylinder. Put air on it and turn the shaft. see what happens.

No adjustments in the manual. I believe you are correct. I put air on it and I am only seeing air coming out of the return line. It is pretty hard to do by myself though. It would be easier in the tractor. I also wonder if a little resistance of the return line would help?

 

[mike48130]

I'm not sue what manual you have but I'm sure there is a pressure spec for it. According to my JD manual for the same type of steering gear/pump, it is open center until you turn the wheel. So no resistance needed.

 

[MrTea]

I'm not sue what manual you have but I'm sure there is a pressure spec for it. According to my JD manual for the same type of steering gear/pump, it is open center until you turn the wheel. So no resistance needed.

There is pressure spec for the pump. The relief vale in the orbital valve is not adjustable. I mounted the valve to the tractor so I could turn the wheel consistently. Most of the air is coming out of the return but there are pulses of air coming out of the left and right lines depending on which direction you turn it.

 

[RickB]

That would be more what I would expect.

 

[mike48130]

That would be more what I would expect.

Agreed.

 

[MrTea]

The manual said the gear inside had to be timed correctly. If it were out of time before could that have caused the problem? I don't see anything that changed but I did time it according to the manual. Before no air would go through and now it will, just wondering how it got fixed.

 

[mike48130]

Maybe your just that good that you don't even realize your fixing things...…

It does look like it was replaced recently. Probably rebuilt wrong. Not the first time a rebuild shop screwed something up.

 

[MrTea]

Maybe your just that good that you don't even realize your fixing things...…

It does look like it was replaced recently. Probably rebuilt wrong. Not the first time a rebuild shop screwed something up.

Pretty weird. I am guessing they replaced the orbital valve and he new one had a malfunctionthat sheared the shaft in the pump. Hoping that it was all a fluke and the new pump fixes it.

 

[wdchyd]

If it was a project I was working on I’d clean out reservoir, replace the pump and add a temporary T right at the pump outlet, then connect a high pressure bypass hose long enough to run into a clean 5 gal bucket, hang a known good direct acting relief valve set at a slightly lower pressure than OEM from the tractor on the end of that hose and place in bucket. This will give you a visual if the pump goes into deadhead condition and a safety for the new pump to help locate a problem, or it will give you confidence that your repair was complete.