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