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Hoe tech in chit chat

MuntCuffin

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Farm lands and horse's asses
Got a deere 310sj with weak hydros. Pressure at lift cylinders for front bucket are less than 1000psi at idle, maybe 1500 to 2000 psi at full throttle.
system releif pressure is 3650psi, I believe.
pressure on hoe boom are pretty much the same. Turning is very difficult at slow speeds or stopped with any weight in the bucket. The stabilizing riggers barely have enough juice to lift ass end of the hoe off the ground.
its had weak hydros since bought it used, but has gotten steadily worse now to the point we can't use it to spread lime. Has about 3600 hours on it. Based on diagnostics I've done, I'm pretty sure its either the main hydro pump or the main relief valve, although the fact that pressure climbs with engine speed makes me lean towards the pump taking a shit.

does anyone know where the main relief valve is on these machines? I'm not a hoe mechanic, but am familiar enough with hydro systems to fuck shit up. Or am I totally off base and need to start looking elsewhere?
 
I'd start looking at pressure output at the pump. If it matches anywhere close to what you're seeing at the cylinders then you know its a pump, if not start moving your gauge around till you find your problem.
 
Is it whining? Suction filter plugged? Since it’s a tractor backhoe is prolly has a gear pump. This rarely fail unless they eat something.
 
Rev the fucker up and let it run of a hour whip out the flir and examine the hydro system. Hot spot = bypass. No hot spot pump weak.
 
Is it whining? Suction filter plugged? Since it’s a tractor backhoe is prolly has a gear pump. This rarely fail unless they eat something.

Not hearing any whining. I didn't even know it had a suction filter.
the guy at deere said it was a piston pump. I'm not sure. I know it's a Parker pump, but all that does is tell you the manufacturer :homer:

here's a pic of what it looks like if that helps. Will look into finding where the suction filter is.

Screenshot_20201222-135323_DuckDuckGo.jpg
 
I would have to see how this is run but I have had issues with a variable displacement Deere pump by having a low pilot pressure. It wasn’t telling the pump to make pressure. So the hydraulics were weak and sluggish.

You could have this issue with the unloader valve.
 
I would have to see how this is run but I have had issues with a variable displacement Deere pump by having a low pilot pressure. It wasn’t telling the pump to make pressure. So the hydraulics were weak and sluggish.

You could have this issue with the unloader valve.

This is what I think as well. Those types of pumps seem to hold up well. Restrictions or unloader.
 
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