Hydraulic question

[Kaliburz]

Got this Italian "in row tiller". It is PTO driven, but has a self contained hydraulic system to move it in and out of the row automatically.

It has this "feeler" arm connected to a valve. As the arm hits something, pushes on the valve and moves the valve, which in turn off sets the equipment, going around the "obsticale" (be it tree or sprinkler riser). The arm and valve move only a little bit, not 100% in and out....it senses how much it has to move and does so accordingly.

Any how, I'm having issues with it. It was working fine, but all of a sudden, it won't move just slightly- lacking a better word, it's not feathering. The arm/valve has to be activated 100% to get it to move at all (and it would be in all the way). I'm not sure what happned..... I thought it was the oil getting hot, since it quit moving and the line was way too hot to touch. Let it cool, works fine. (The bypass is adjusted correctly- open center hydraulic system- pump is working fine- gear pump.)

I took apart the valve, looking at it. There are grooves in the valve and I wondered if something was missing... like O rings.... they should be there.....I thought. Part of me "thinks" there should be an O ring there, but can't see if it had any at one point. There isn't any in the valve body (and I can't seem to get a parts breakdown of it either). Do control valves have O rings on the spools? I've never taken one apart to look..other then this one. Kind of ticking me off....wanted to use it this year, but w/ it not going in/out correctly, it would take out a tree....

Thanks in advanced.

 

[BTDT]

Sounds like an interesting setup. We need pics. Yes, there are o-rings in the spools, but to me it sounds as if something got out of adjustment, and maybe a stuck relief valve, if lines are as hot as you say. Is this a selfcontained unit?

 

[Kaliburz]

Yes, self contained. Pump runs off of the back end of the gear box via PTO. I adjusted the relief once thinking it was it- dumping too early, nearly turned it into a closed center system, so yes, the relief works....nearly closed it off. I backed it off to where it was originally. System worked fine for two/three years (bought used, but said to be hardly used). Didn't touch nothing and then one year it quit moving in and out.... oil was HOT, hence I checked the relief (even changed fluid).

I'll have to double check the spool. I swear there wasn't any O rings on the spool.....

Will work on getting pics....

 

[Kaliburz]

The pic....

The unit is made in Italy and was imported to Canada and made it's way to the US. As you can see, it has two 'fingers' that engage the ground in each section. If I remember, there are 5 or 6 sections. Each rotates the opposite of the one next to it. It's gear driven, basically one big gear box.

As I said, the hydraulic system is self contained and the feeler arm on it's right (closest to bottom of pic) activates the control when an obstical is hit. As of right now, it's not working correctly....

 

[slowzuki]

Shouldn't be o-rings in the grooves if they are the ones I'm thinking. Check for anything at all sticking, linkage or valve. The guide should shift the valve back to neutral once it moves out of the way.

If there is nothing sticking it sounds like the open centre drain to tank is blocked. This would cause the fluid to heat up. Maybe there is a filter on this line. This would prevent the valve from returning to centre if too much pressure was building up causing the relief valve to operate too.

Just something mechanical sticking the valve in the hard over position will cause it to relief and heat the fluid too though.

Hope you can track it down. The groove btw are where the oil passed in the spool to get between the ports.

 

[Kaliburz]

Another 'thought' that came to mind was the weight of the unit. As you can tell, it's a heavy beast. The wheels support the 3pt, but nothing supports the back. According to the parts breakdown, the pivots have sealed bearings in them. Knowing my luck, (LOL), it could be possible that some bearings are going bad and binding up and that's why the system is not moving unless it gets full flow. I should mount the unit and unhook the cylinder and see if the thing moves side to side smoothly..... I think there are 10 bearings that support it.

Yes, there is a hydraulic filter. I 'should' change that too... I haven't really taken a look at breakdowns of hydraulic control valves. I just know a bit about reading hydraulic schematics and putting together systems for my tractor.

Unit is a Rineri (spelling) and the importer to North America is in British Columbia, Canada. There's quite a few around in this area used in orchards. Great way to kill weeds when its an organic orchard (or to kill weeds when one doesn't want to use Roundup...)