8N 3PT not raising high enough?

[BossofBBQ]

Hey Folks,
I'm back again with (I hope) a simpler question than last time...
I don't think my 8N's 3 point is raising high enough. Measured at the link balls (at the very end of the lift arms) , it only raises to 25 inches. I can manually lift the entire 3pt mechanism for another 7 or so inches above that. If I lower the hitch all the way down, the link balls drop to only 4 inches above the ground. The only thing stopping them from going lower is the leveling box hitting the axle casting.

The hydraulics seem strong. It lifted my 6' Ford disc fine, but couldn't get it fully off the ground because that would mean lifting past the 25" mark.

Is there a way to adjust the hydraulic travel/range of motion?

 

[RayIN]

That kinda sounds like the relief/overpressure valve is bad on the hyd pump.

 

[Roadworthy]

See if there's a stop on the lever that operates the three point. Many tractors have them to set upper and lower limits on the three point. I use mine to limit the lowering point of my mower so it doesn't drag.

 

[EdGooding]

Hey Folks,
I'm back again with (I hope) a simpler question than last time...
I don't think my 8N's 3 point is raising high enough. Measured at the link balls (at the very end of the lift arms) , it only raises to 25 inches. I can manually lift the entire 3pt mechanism for another 7 or so inches above that. If I lower the hitch all the way down, the link balls drop to only 4 inches above the ground. The only thing stopping them from going lower is the leveling box hitting the axle casting.

The hydraulics seem strong. It lifted my 6' Ford disc fine, but couldn't get it fully off the ground because that would mean lifting past the 25" mark.

Is there a way to adjust the hydraulic travel/range of motion?

Your range of motion should be closer to 8" at the lowest and 33-34" at the highest. This assumes you have 28" rear wheels.

You may be looking at an overhaul of your top cover. Do you have any manuals?

 

[John0829]

Ed gave you the proper measurements, more likely than not someone put the lift arms back on it the wrong position when doing an R&R of the top cover. As for the free travel at the top of the lift, you will have some due to how the hydraulic cylinder is connected to the lift arms using the dog bone link.

 

[BossofBBQ]

Ed- my tractor has the 28" wheels, and I just recently obtained all the manuals: I&T FO4 service manual, Owners manual, and a master parts catalog/assembly manual.

I was out fiddling around with my middle buster/potato plow today, and made an interesting discovery: the 3pt won't raise at all when in "draft control" mode. When this happens, the lever under the seat is fully horizontal. But, if I continue to apply moderate downward pressure to it with my hand, my 3pt will raise to a full 34" and function correctly. When I stop manually holding the "draft control" lever down, I lose all hydraulic power. The lever is still horizontal at this time. If I switch the lever vertical (Position control), the arms only raise 25" above the ground.

I am running fresh TSC Traveller Brand UTF and the level is right up to the "full" mark on the dipstick.
Roadworthy- my tractor does not have a nifty stop on the adjuster lever, so there's nothing to restrict movement there.

I know these problems are difficult to diagnose online, but I couldn't seem to find any symptoms that match mine in the manuals. Something is obviously worn/broken internally, but how would I go about pinpointing the issue?