1947 Ford 2N 3PT Not Lifting

bamboozled · Apr 1, 2015

Hey guys - I've been helping a guy I work with try to get one of his Grandpa's tractor back in service, the issue is that the 3PT lift arms to not raise. According to his Grandpa when he bought it the 3PT worked, but he put the tractor away last fall and when he went to use it to plow snow the lift arms wouldn't raise anymore.

So far we inspected the top cover through the inspection ports, and there doesn't seem to be any leaking coming from the lift cylinder or pressure tube.

Today we drained the sump to get a better look and ran the tractor to see if the bypass was opening, it does not appear to be.

We noticed that the control valve seems to be stuck, possibly bound in the bore. When we move the lift arm lever, the forks seem to move the T-bar on the control valve up and down, the control valve does not move forward or rear, in line with the tractor and its bore, like what I would expect a spool to do. Is this the correct assumption in function? Could it be a pin in the top cover has broken and it is now causing the control forks to move up and down instead of forward and back? I should have gotten some pictures but it was getting late in the day and we needed to get back.

I have the I&T manual from TractorSupply for reference, just trying to help an old guy get back up and running so any insight from someone more experienced on this machine is appreciated.

kydick · Apr 1, 2015

maybe the pto needs to put in gear to make it work. 1950 8n has to work this way.

bamboozled · Apr 2, 2015

Yes, the PTO does have to be engaged and the clutch released for the pump to work.

bamboozled · Apr 2, 2015

Today we pulled the pto shaft out and attempted to manually slide the control valve and it was stuck tight. We dropped the pump out and were able to knock the control valve loose, there was a bunch of crud in between the spool and bushing. We cleaned both up and the control valve then would slide in and out decent but we are still going to clean and rebuild the pump before reinstalling it.

bamboozled · Apr 6, 2015

Video of the lift lever prior to dropping the pump and finding the stuck control valve spool. Parts showed up today, tomorrow we rebuild

bamboozled · Apr 8, 2015

We spent the last couple days tearing the pump down, scrubbing and now putting it back together. A few interesting things we found were that there was an old control valve plunger broken off and laying in the bottom of the sump. We also found that the control valve that was in place had a bent plunger in it.

We also found that the new 'pistons' for the pump were offset slightly one side to the other, so they had to be lined up properly to fit into the side plates. They aren't marked and had to be test fitted before the difference was noticed.

Looking forward to reinstalling the pump and going for a trial run, hopefully tomorrow.