Odd Cylinder Response to Control Level Action

[Korishan]

I ran into an odd issue today. First off, I got the tractor a bit stuck (it sunk into the mud as I was digging a pit for a septic tank replacement; it's been raining a lot lately), and I had to lift the tractor up to put some boards under the tires to get out of the hole-ramp. Well, I was able to get the stabilizer arm down and help pick up the tractor (note, these are the same cylinders I'm "thinking" I need to replace the seals as they don't stay down).

Ok, so when I go to lift up the cylinder, we've had to pick up on the foot with a rope to help get it up and tie it off. We usually pull the rope while activating the raise lever to make it easier. Today, the tractor was revved up to about 1600rpm and I tried to lift the arm. It would not budge. I was thinking "oh crap" as I needed to get it up so I could drive out of the ramp-hole. I tried different ways of pulling it up with the lever, without the lever, no go. So, I ended up throttling the rpm down to idle of about 600rpm. At that point, I was able to pick up the arm with the lever with assistance of the rope.

Now, why would the arm "not" go up when the engine was revved up, but at idle it acted completely differently and was able to go up? Is there possibly a bleed issue in the hydraulic control valve for the backhoe?

I also noticed that I was having issues raising the tractor up with the bucket. I had to give the boom down lever little action to help pick up the tractor. If I pushed it 1/2 way or more, it would drop back down.

Could it possibly be the hydraulic control valve that's leaking fluid and not the hydraulic cylinder piston seals? If so, how can I for sure rule this as the case, or rule it out?
Note: I currently don't have a hydraulic pressure gauge.

TIA,
Kori

 

[Xfaxman]

Maybe it is low on hydraulic fluid and sucking air at the higher flow.

At idle it should develop max pressure, opening the relief valve.

 

[Korishan]

Ahhh, I didn't think of that. Very quite possible as the tractor was at about 5-7Deg nose up. If it was low, probably did as you said. Will check it tomorrow.

Thanks