Hydraulic pump rebuild?

[jds535]

Hello all,
Working on my new to me 52 8n. When I bought the tractor the hydraulics were seized up. The lift Handle was stuck and wouldnt move, the lift arms were also stuck on the bushings and wouldnt go up or down. The previous owner just used it to tow trailers around for years apparently. I got the top cover off and got everything freed up. New lift cylinder and piston, new pivot pin and put it back together.
The arms lift now but seem weak. When I stand on the 3 pt arms and lift them up, I can feel the pump pulsing a bit like it is laboring. ( I weigh 235 ) Also, I do not see a lot of movement in the oil when its going up and down, and no oil raining down from the top cover at all. ( I saw a video that said that was important ) ??
Does this point to pump rebuild?

FYI, its got enough oil showing on the stick. The oil is just a bit milky, but not terrible. The speed of the lift is comparable to my old 9N I think.

 

[JMOR]

It is a four cylinder pump running at slow pto speed, so it is going to pulse. It should lift over 1,000 pounds directly over drawbar.. Speed of lift will depend on engine speed. Test port should show around 1600-1700 psi with a very heavy load or lift arms chained down.

 

[jds535]

OK, I get what your saying about the lift. And it looked smooth as it went up. I wouldnt have noticed any pulsing if I wasnt standing on the lift arms.

But I really expected to see more oil moving around inside the right inspection cover. ?? How does the lift cover components get lubricated?

Thanks, jeff

 

[JMOR]

(quoted from post at 16:45:34 07/29/23) OK, I get what your saying about the lift. And it looked smooth as it went up. I wouldnt have noticed any pulsing if I wasnt standing on the lift arms.

But I really expected to see more oil moving around inside the right inspection cover. ?? How does the lift cover components get lubricated?

Thanks, jeff

hey reall don't, other than by vapor and a little sloshing/splashing. Only thing moving oil in there is the scotch yokes in pump and that isn't much. Reason most taken apart are rusty.

 

[Dave G9N]

I have just removed the pump from a 2N that had a very jerky lift. I have a 9N with a smoother, but still jerky lift and used to use a 9N with a much smoother lift, at least as I remember it from a few decades back. The lift cylinder, lift cylinder piston, Pump cylinders and pump pistons were all badly scored. The lift bounced the load up.

I hate to argue with JMOR on account of my lack of expertise and likelihood of loosing the argument on account of being wrong. I will speculate that my badly scored pump pistons were the reason for the jerky performance of my lift. I suspect JMOR of taking care of his equipment to the extent that he rarely experiences just how badly it can run when severely neglected, and then only on someone else's tractor. Could be what he calls pulsing seems smooth to me.

Since I am still performing surgery on the tractor in order to get the oversized chinese pump parts through the hole in the bottom of the tractor, I can only hope that it will run smoothly when I am finished.

The only comment I could find that seems to corroborate that a badly scored pump piston could cause rough operation was in one of the Rachel Gingell videos. She commented on how smoothly the lift was operating after the rebuild. That infers that the lift did not operate smoothly before.

 

[Abbby]

If you have not changed fluid that should be done first.

 

[Hobo,NC]

Pick something up heavy and report back, 235 directly on the draw-bar is not a stress test. Standing on the lift only tells me it functions and just coasting along.

There will be some swirl to the oil center of the pump when the PTO is operating its the nature of the beast. Its like beating a egg the pump chambers and PTO shaft are like the reaction of using a fork to scramble yer egg. .

 

[JMOR]

(quoted from post at 18:48:34 07/29/23) I have just removed the pump from a 2N that had a very jerky lift. I have a 9N with a smoother, but still jerky lift and used to use a 9N with a much smoother lift, at least as I remember it from a few decades back. The lift cylinder, lift cylinder piston, Pump cylinders and pump pistons were all badly scored. The lift bounced the load up.

I hate to argue with JMOR on account of my lack of expertise and likelihood of loosing the argument on account of being wrong. I will speculate that my badly scored pump pistons were the reason for the jerky performance of my lift. I suspect JMOR of taking care of his equipment to the extent that he rarely experiences just how badly it can run when severely neglected, and then only on someone else's tractor. Could be what he calls pulsing seems smooth to me.

Since I am still performing surgery on the tractor in order to get the oversized chinese pump parts through the hole in the bottom of the tractor, I can only hope that it will run smoothly when I am finished.

The only comment I could find that seems to corroborate that a badly scored pump piston could cause rough operation was in one of the Rachel Gingell videos. She commented on how smoothly the lift was operating after the rebuild. That infers that the lift did not operate smoothly before.

o argument , Dave, the fewer cylinders actually pumping, the more jerky, down to 3, 2, 1