8n hydrolic arms

[Snitkerb]

I finally was able to get my tractor running very well, and it can pull a load without trouble. Was in the garden the other day to plow and the lift arms will not lift my plow and cannot keep weight for more then a few seconds after the clutch is pressed I want to look into the lift this week and get it repaired. Can anyone tell me the most common problem I should find? Assume piston rings are no longer good and also will try a safety valve. Any other things I should expect I find?

 

[Ultradog MN]

I think you have it figured out.
Pull the top cover and renew the piston and seals with the NAA type.
Also replace the cam follower pin as a matter of course.

 

[souNdguy]

yup..leak is likely overcomming pump volume making leak lift that drops super fast.

 

[Snitkerb]

What do you mean by the NAA type? Are you talking about the single O ring piston?

 

[fordmanmatt]

you might need to adjust it after the rebuild i used the old three ring type piston and it has been fine

 

[Bruce (VA)]

If the arms drop w/ the tractor off or the clutch depressed, chances are you have a worn lift cylinder or piston (or both), a blown top cover gasket or a leaky pressure relief valve. Take the inspection plate w/ the dipstick off. Lift a heavy implement & look inside w/ the tractor running & the PTO engaged to see if you notice oil running from the top cover. If oil is running steadily from the top cover the chances are the lift cylinder needs to be rebuilt. It?s less likely, but a possibility, that the top cover gasket is bad. (It?s very difficult to detect the exact source of the oil leaking inside of the top cover while looking through the inspection port). If no oil is running down from the top cover, look at the rear of the pump in the oil with the load still on it and see if you notice turbulence in the bottom. (Some movement of oil will be normal with the PTO shaft turning). You could have a weak pressure relief valve which will be detected by turbulence in the oil. To check for a slow leak, lift a heavy implement, turn the tractor off & put a ? inch clear plastic hose on the end of the valve & stick the other end of the hose through the inspection port. With pressure in the pump, a bad valve will likely show some fluid in the hose.

Post back with what you find from the inspection & we'll go from there.
75 Tips

 

[Den N Ms]

Snitkerb,Pull the dipstick cover off the right side and with some weight on your 3 point,raise it up and with it running look inside with a light and look for leaks.Shut it off and look for leaks.It could be just a bad relief valve,you can slip a hose on the end of it to check it.

 

[Snitkerb]

I'm planning on doing a little work/checking on it this evening. Thanks for the advice, I'll post back later today with what I find.

 

[HCooke]

"What do you mean by the NAA type? Are you talking about the single O ring piston? "

Yes.

 

[R Geiger]

(quoted from post at 01:30:14 03/08/16) What do you mean by the NAA type? Are you talking about the single O ring piston?

Ya that is what UD means, but if the cylinder is scored up, the cylinder should also be replaced. Myself, I use the original piston and rings.

 

[Snitkerb]

Ok so here's the update...just hooked back up to the plow, pulled the cover, and I did not notice any oil leak. Granted it's hard to see everything with the tire still on, but I didn't see anything obvious. Was turbulence in the oil, but I didn't notice much change in it with and without pto lever on. I also didn't know what to look for in te relief valve, should it be obvious?

 

[Tom N MS]

Had two within few months of each other that leaked down so fast, the implement would drop to the ground as soon as u pressed the clutch---both had bad safety valve...Other ways to test but raise the load-kill the engine and put your finger over the end of the safety valve--if it is leaking bad you will feel pressure trying to puch your finger off of the end of the valve..

 

[howdy1960]

I had a blown gasket on the pump where side chamber? mounted.
Arms dropped with-in 5 seconds even with out a load, faster with a load.

 

[Snitkerb]

My local Napa pulled through and has a relief valve I will be picking up this afternoon, with luck I'll have that replace tonight. Does anyone know the wrench size I'll need? I'm alright with buying one to cut down just for this job, and is it possible to replace from the side panel?

 

[HFJ]

the wrench is 11/16" - i've noticed this is a popular size on Ns.

this thread should help u:

http://forums.yesterdaystractors.com/viewtopic.php?t=363452

 

[Snitkerb]

Alright, it was the pressure valve. Works like it should now.