Loader refurbishing worse than when I starte

[woolyAcres]

I just completed an overhaul of my tractor's (Yanmar YM240D) loader hydraulics. Now that everything is re-assembled I get a shuddering and screetching when I operate it and all 4 functions aren't working correctly. Could this just be air in the lines that hasn't been purged yet?

This overhaul included installing a new Brand Hydraulic joystick loader valve (replacing an older 2-lever arrangement) as well as moving the supply for this system from the tractor's main hydraulic pump to one that is mounted at the front and runs off a shaft sticking forward from the engine. The pump is working because I can see fluid returning to the tank. Raising the boom works okay but there is some shuddering and noise when doing so. Lowering works as well but there's shudder and screeching there. Curl and dump don't function as well, but during the overhaul, because the cylinders were vertical, with no hoses attached at one point, more fluid leaked out of them.

Additionally, the pressure relief valve (which should be set to 2000psi for this new valve) doesn't seem to be relieving pressure. I have a pressure gauge T'd into the system and it can/does spike at over 4000psi, nearly stalling the tractor.

Could this all be caused by air in the system that can/should bleed as I work through all the functions? Or should I be looking for other issues/solutions?

The noise and shuddering made me nervous enough to stop and think (and ask) about what's going on here. I don't want to damage the tractor, new loader valve, or anything else.

Thanks,

 

[TomSeller]

That relief needs to be functional before you blow a hose. There might be air in the lines, but that will come out with cycling the cylinders. Do you have information on the relief and are you sure it is piped correctly? Where is the relief relieving to?

 

[woolyAcres]

Hi Tom, thanks for your comments.

My understanding, or more like assumption, is that the relief valve contained in the loader valve would allow excess pressure to return to the tank. Is that incorrect?

For what it's worth, with the loader valve in the neutral position, the tractor runs fine (no lugging), and fluid flows freely. No noises, or shuddering. My guess is that the relief valve in the loader valve isn't working correctly but there's no special plumbing for that so maybe I assume too much about how this valve relieves pressure.

 

[woolyAcres]

Do you have information on the relief and are you sure it is piped correctly? Where is the relief relieving to?

Here's a link to the loader valve, which I thought contained a relief valve.
My model is the LV22RFSTKAB.

 

[dynasim]

You have installed something incorrectly. Don't run it again until you figure it out. Most of the time, an ill-functioning relief valve yields a cracked housing. The pressure should never go over the relief setting.

Chris

 

[oldnslo]

Hi Tom, thanks for your comments.

My understanding, or more like assumption, is that the relief valve contained in the loader valve would allow excess pressure to return to the tank. Is that incorrect?

For what it's worth, with the loader valve in the neutral position, the tractor runs fine (no lugging), and fluid flows freely. No noises, or shuddering. My guess is that the relief valve in the loader valve isn't working correctly but there's no special plumbing for that so maybe I assume too much about how this valve relieves pressure.

On the replacement brand valve did you remove the power beyond plug? The relief valve drains to the "T" tank port on the brand valve. If this valve is not connected and plumbed properly the relief won't work.

On the chattering and noise. Is the pump on the front of the engine a new installation? If yes is the inlet hose sized large enough to allow full flow to the pump? Also if the valve isn't plumbed correctly could cause the jumping and jerking along with air in the system.

 

[/pine]

Can you post a picture of the valve and identify all four of the lines connected to the working ports...?

 

[woolyAcres]

On the replacement brand valve did you remove the power beyond plug? The relief valve drains to the "T" tank port on the brand valve. If this valve is not connected and plumbed properly the relief won't work.

I've got this Brand valve plumbed as follows.
1. 3/4" hose comes from pump to "IN" on the valve. There's a T on this line where my pressure gauge is installed.
2. 3/4" hose leaving the valve via outlet port which goes to a filter then to the tank.

On the chattering and noise. Is the pump on the front of the engine a new installation? If yes is the inlet hose sized large enough to allow full flow to the pump? Also if the valve isn't plumbed correctly could cause the jumping and jerking along with air in the system.

This pump isn't actually a new installation. It was there when I bought it but not coupled to the engine, front shaft. In reality it's a 'new' installation for me.

 

[woolyAcres]

Can you post a picture of the valve and identify all four of the lines connected to the working ports...?

Here's a clip from the link at the top. I can post a photo of MY valve installation tomorrow.

 

[woolyAcres]

On the replacement brand valve did you remove the power beyond plug? The relief valve drains to the "T" tank port on the brand valve. If this valve is not connected and plumbed properly the relief won't work.

I did not remove the PB plug. Which port on this valve is T port?

Thanks

 

[/pine]

Here's a clip from the link at the top. I can post a photo of MY valve installation tomorrow.
View attachment 453913

Without knowing more where this valve is installed (i.e., with the 3ph etc...) and the PB setup I can't offer an observation...this could be your problem...but my first thought was...it is easy to cross working port hoses in confined spaces and if you're not familiar with multiple spool valves the labeling can be a bit confusing...never have understood why A1 and A2 don't work one spool and B1 and B2 work the next etc. etc...

 

[skyhook]

I'm by no means an expert on this, but I did read the pdf for your model. Have you tried to loosen the relief vale and adjust it "down"...To adjust relief pressure: First, remove the acorn nut with 1/2 wrench. Next, loosen the 1/2 hex jam nut. Using a
5/32 allen wrench on the relief adjustment screw one full turn clockwise will increase pressure by 200 psi, turning it counterclockwise will bring the relief pressure "down".So turning it down 8 or 9 full turns should drop down the relief pressure. "If" that is the problem, it does sound like the relief is not kicking in or, the hose are installed incorrectly.

 

[woolyAcres]

Without knowing more where this valve is installed (i.e., with the 3ph etc...)

This should be a pretty straight forward install because it's really a stand-alone setup.
pump is mounted to front of engine (via shaft)beneath battery
pressure line goes from pump to loader control valve
return line goes from loader control valve to filter
from filter it goes to tank
suction line goes from tank to the front mounted pump

That's it. No power-beyond, no other remotes, etc. Just a simple, contained system.

I've checked that the A1,B1,A2,B2 go to the correct places, but it's certainly worth checking again. I think they are right because the functions all work. I briefly tested them by moving the joystick just a touch. I'll confirm this later today but my memory is that moving the joystick just a bit (no fully opening the valve) and the function works. However opening it all the way is what causes the pressure to spike.

It's a pretty confined space so it's certainly possible something got connected incorrectly. I'll checking that everything goes where it should before trying it again.

 

[woolyAcres]

I'm by no means an expert on this, but I did read the pdf for your model. Have you tried to loosen the relief vale and adjust it "down"...To adjust relief pressure: First, remove the acorn nut with 1/2 wrench. Next, loosen the 1/2 hex jam nut. Using a
5/32 allen wrench on the relief adjustment screw one full turn clockwise will increase pressure by 200 psi, turning it counterclockwise will bring the relief pressure "down".So turning it down 8 or 9 full turns should drop down the relief pressure. "If" that is the problem, it does sound like the relief is not kicking in or, the hose are installed incorrectly.

I'll try this. Is it possible to unwind the relief too far? I suppose something would come flying out.

 

[LD1]

Before you do anything I would like to see some pictures of how you are setup. And if possible, try to get shots showing where the hoses go to.

I am intimately familiar with this valve after having just installed one of them on a IH 444. Exact same valve actually. With first spool regen and second spool float functions. Some of the literature supplied by surplus center is just plain wrong, confirmed by contacting brand directly.

 

[TomSeller]

I'll try this. Is it possible to unwind the relief too far? I suppose something would come flying out.

It would not hurt to run the relief all the way to the lowest pressure as suggested above until you figure this out. A sketch of how you piped it would help in addition to the pictures.

A1 and B1 go to the same cylinder (Curl). A2 and B2 go to the same cylinder (Boom). Wouldn't hurt to check that. 1s go together and 2s go together. Not As and Bs. Diagram is in the PDF showing which port gets the rod end of the cylinders

http://www.brand-hyd.com/lv/catalog.pdf

 

[woolyAcres]

Here are some photos of my setup and how I intended to plumb it. I tried to stay consistent. RED indicates high pressure lines, green indicates low pressure, suction, or return lines. I need to confirm that all the ports are connected correctly (A1,B1, etc). I've got to move some cows but will check on that as soon as I'm done getting those heifers to the barn.

Thanks in advance for all the input. I really didn't think I was taking on too big a project. In my head, this isn't a very complicated system. I've either made a simple mistake, or underestimated the difficulty and overestimated my understanding- wouldn't be the first or last time


I can't seem to upload any files right now so I'll have to try again later.

 

[woolyAcres]

Maybe this dropbox link will work:

 

[woolyAcres]

I confirmed the lines are connected correctly and in fact, after adjusting the pressure relief valve (down to 1000psi) things seem to be going better. I think maybe the relief valve was stuck. I plan to adjust it back upward to 2000psi but I've still got a problem to solve. It seems the system is really sucking air from somewhere. After running for about 3 minutes the tank overflowed because of all the air it had drawn in.

What's the best way to identify a suction leak?

Secondly, what symptoms should one expect from a system where the pump is too large for the valve? To this day I've not been able to find any markings on the pump to identify it so I don't know what volume it is. The valve should handle up to 10GPM. The tank is about 4 gallons so I expected the pump to be close to that. However, I think I'm assuming too much about the previous owner.

 

[LD1]

Valve too small for pump would cause a wine and overheating.

Suction.leak...did you have one before. Or are you still trying to expel the air out of the system?