8N Lift

[SteveRusssell]

The tractor is a 1952 8N after sr#216xxx, side mount distributor, 4 speed. 6volt, positive grnd.
Situation: The lift would no longer "lift" an implement. It would until recently, but always leak down quickly , if motor was shut off. Couple months ago I did the Quick fix of changing the fluid and Washing out the houseing with Diesel. NO change. Whis past week I drained it again, took off the side plates and also changed out the piston in the cylinder to the NAA530b with the O-Ring and leather back up, did hone the cylinder, but it was not in bad shape. Washed and blew it out and installed new fluid. The lift arms would go up very quickly but would not go down until I adjusted the area of the quadrant. I did not take the pump out, I had the bolts out and tried to drive it out with a 2x4 like the boys on the DVD did, but it was so tight I was afraid of breaking it.
It will now lift the implement quickly,& hold it with motor running, only, or drifts down quickly, when motor is turned off.. What would be your suggestion to get this working correctly? Is there an adjustment yet, or get a bigger hammer to get the pump out and rebuild it. The tractor is 150 miles away, so can't run outside to double check anything now.
Thank you.

 

[R Geiger]

Hope you took the PTO shaft out before you tried to remove pump.

 

[Bruce (VA)]

" took off the side plates"

What did you see when you did that?


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 ½ 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.

Assuming you rebuilt the lift cylinder correctly, the next likely cause of the problem is a leaky pressure relief valve.

Did you adjust the internal linkage while you had the top cover off? If not, that would explain why you had to fool w/ the quadrant adjustment. If the cam follower pin is worn, you will never get it adjusted correctly.
50 Tips

 

[souNdguy]

I had no trouble dropping the pump.. the top cover was what took a jack and 2x4 to remove.

as rg points out, the pto shaft has to come out to drop the pump..

soundguy

 

[ZANE]

I would replace the pressure relief valve before I did anything to the pump.

It screws into the back of the pump just under the PTO shaft. Need a boxed end 11/16 end wrench bent in the middle to 90% to remove it.

Zane

 

[Hobo,NC]

It never hurts to do a throw inspection to determine lift issues,,, theirs no such thing as a quick fix, spray wipe and go are any other of that bogus info you have read,,, its more of a feel good issue that you have done sum'n good quick and fast,,,, when all you did was waist good money and yer time....


Lets say your lift piston repair was done rite and theirs no issue their,,, you could do the diagnostic routine are jump the gun and go for the relief valve,,, you are gonna have the inspection covers off any ways so do the diagnostic routine... well mite as well have a relief valve on hand and swap it out while their....


http://www.theviperr.info/hobo_dnn/Default.aspx?tabid=114

 

[SteveRusssell]

Thank you all for your comments and insight. S Russsell