Loader refurbishing worse than when I starte

[LD1]

I thought I posted a reply, but guess not. phone may have acted up or I got one of those "leave this page" things and it failed to post.

In either case, I have never needed more than ~5psi to find a suction side leak doing what I describe. I have a little regulator that gets tons of use. male air fitting on one side, female on the other. Hook it in when painting, pressure testings things, etc. as it is easier than dialing the one down on the tank that is behind the workbench and has a crappy gauge.

Isolate the suction line up to pump. Dont pressurize the tank. But it should be vented anyway.

 

[Coyote machine]

Just curious if the filter head is plumbed correctly? In and out direction toward reservoir/tank. If it were my tractor I'd get some of the multi colored tape rolls, available in most hardware stores, and tag each line on both ends with a particular color, and then make a 'key' to what goes where.
I can't tell from your pics how the pump is oriented, but it seems to me the suction line goes highest and then makes an awkward 180* entry into the pump. I wonder if you're creating cavitation in this series of fittings where the pump is pumping faster than the suction line can supply 'airless' hydraulic fluid, especially when you open the FEL valve wider than say idle?

Also, you've used T-tape, yes? to seal all your connections. If so, is it possible there is a fitting that is allowing air into the system on the suction side, because of a tight, but not sealed threaded fitting? You might be able to use a soapy solution of water and soap to see if suction is present at any suction side fittings.

Just throwing stuff out here, I'm no hyd expert by any means...

 

[TomSeller]

This isn't plumbed into the normal 3Pt yanmar setup. Hopefully the images I uploaded will be more accessible and give a good idea of what I'm working with.

I drained and cleaned the tank before refilling. The cylinders had clean fluid in them (rebuilt them about 3 months ago). The only place there could have been junk, is in the suction line since I never removed it. The high-pressure line is brand new. When the fluid in the tank has been sitting I can look to see if there's anything in it. It should be pretty clean but it's worth checking.

How can I tell if my filter is letting air into the system?

I did not know your hydraulics were not integrated into your tractor transmission as a tank. With your setup, you may not have a strainer. But you might. It would be at the point the suction line picks up the fluid from the tank. It would not be letting air in since it should be immersed in fluid. if a strainer is PLUGGED, the pump draws in what it can and any small hose/tube/fitting leaks let the air in. A strainer in your case is intended to keep out any debris that gets into the tank from the opening or in transmission tanks, any metal bits or whatever. In your configuration, I would have put the filter on the suction line and done without the strainer.

 

[GPintheMitten]

I did not know your hydraulics were integrated into your tractor transmission as a tank. With your setup, you may not have a strainer. But you might. It would be at the point the suction line picks up the fluid from the tank. It would not be letting air in since it should be immersed in fluid. if a strainer is PLUGGED, the pump draws in what it can and any small hose/tube/fitting leaks let the air in. A strainer in your case is intended to keep out any debris that gets into the tank from the opening or in transmission tanks, any metal bits or whatever. In your configuration, I would have put the filter on the suction line and done without the strainer.

His loader is NOT using the transmission and 3 point hitch hydraulics.

 

[Coyote machine]

His loader is NOT using the transmission and 3 point hitch hydraulics.

The tractor has two separate systems. The FEL is now isolated from the original hydraulic system, and runs off a front shaft on the tractor, to supply hydraulic fluid/pressure to just the FEL.

 

[TomSeller]

His loader is NOT using the transmission and 3 point hitch hydraulics.

Sorry, typo. Corrected. I at that time knew they were not integrated, hence the rest of that post.

 

[woolyAcres]

Just curious if the filter head is plumbed correctly? In and out direction toward reservoir/tank.

I believe it is. Picture 004.pdf shows a view looking down on the valve, filter, and tank. In my version (which is probably higher resolution than what I was able to post) there's an arrow visible on the filter (not the green one I added). It shows flow entering via the flex hose and then exiting right into the tank.

I can't tell from your pics how the pump is oriented, but it seems to me the suction line goes highest and then makes an awkward 180* entry into the pump. I wonder if you're creating cavitation in this series of fittings where the pump is pumping faster than the suction line can supply 'airless' hydraulic fluid, especially when you open the FEL valve wider than say idle?

Sorry the photos aren't great. The pump sits right behind the front grill, below the battery. I've removed the hood and battery stand to get to the pump. The photo showing the pump (006.pdf) is looking straight at the tractor. I'm standing in the FEL bucket. The lights would be about a foot above the pump and shining right into your eyes. I agree that the suction line makes an akward 180* turn just before entering the pump. I thought cavitation might be an issue, though I hope it's air suction.

If I were to remove the valve from the system and plumb the tank to the pump then to the filter and then the tank that might tell me if the valve is too limiting? I have run this pump once before when testing to see if it worked. The fluid was milky and garbage, but I don't remember the fluid getting frothy.

Is there any problem with pumping straight through the filter?

Also, you've used T-tape, yes? to seal all your connections. If so, is it possible there is a fitting that is allowing air into the system on the suction side, because of a tight, but not sealed threaded fitting? You might be able to use a soapy solution of water and soap to see if suction is present at any suction side fittings.

I used a teflon paste on all new connections. I suppose a tight but not sealed fitting is possible. Would suction show up using soapy water?

Just throwing stuff out here, I'm no hyd expert by any means...

Neither and I I do appreciate all the suggestions. I couldn't get away from other things to work on this today but did have internet access so I've been doing more research than fixing. Hopefully tomorrow. Besides, it's supposed to be warmer tomorrow (high of 19F instead of today's 10F).

 

[woolyAcres]

I did not know your hydraulics were not integrated into your tractor transmission as a tank. With your setup, you may not have a strainer. But you might. It would be at the point the suction line picks up the fluid from the tank. It would not be letting air in since it should be immersed in fluid. if a strainer is PLUGGED, the pump draws in what it can and any small hose/tube/fitting leaks let the air in. A strainer in your case is intended to keep out any debris that gets into the tank from the opening or in transmission tanks, any metal bits or whatever. In your configuration, I would have put the filter on the suction line and done without the strainer.

I didn't explain the setup at the beginning very well. I was trying not to overwhelm the reader. My apologies.

My setup, for the FEL, doesn't have a strainer. The only thing here that could remove any bits is the filter. I hope that's sufficient. I really don't know.

I dithered about the location of the filter but based on this article, I opted for return-line filtration. I suppose I could move this if there's good reason to (like way too much air getting into the system).

Could I have this whole dumb thing plumbed backwards? Looking at the pump (006.pdf above) which side is the high pressure side and which side is the suction?

 

[TomSeller]

Could I have this whole dumb thing plumbed backwards? Looking at the pump (006.pdf above) which side is the high pressure side and which side is the suction?

Is the pump not marked? In should say in for your suction and out for your pressure. There are quite a few fittings in that suction line from looking just at the pump end. What fluid did you use? Do your supply or tank hydraulic lines get very warm?

Soap on a suction line is not good if there is a leak, you would only do that on a pressurized line.

 

[Coyote machine]

I believe it is. Picture 004.pdf shows a view looking down on the valve, filter, and tank. In my version (which is probably higher resolution than what I was able to post) there's an arrow visible on the filter (not the green one I added). It shows flow entering via the flex hose and then exiting right into the tank.

Assuming your direction of flow throughout the pump and lines is correct then this would make sense.



Sorry the photos aren't great. The pump sits right behind the front grill, below the battery. I've removed the hood and battery stand to get to the pump. The photo showing the pump (006.pdf) is looking straight at the tractor. I'm standing in the FEL bucket. The lights would be about a foot above the pump and shining right into your eyes. I agree that the suction line makes an akward 180* turn just before entering the pump. I thought cavitation might be an issue, though I hope it's air suction.

Cavitation is essentially air turbulence caused by scarcity of fluid to be pumped through the system. That's why I question the possible uphill run of the supply from the tank to the pump, AND it's shared and narrow bend 180* turn, with the current fittings... This could be a flow restriction point that allows the pump to get ahead of the fluid flow? Hypothesising here...

If I were to remove the valve from the system and plumb the tank to the pump then to the filter and then the tank that might tell me if the valve is too limiting? I have run this pump once before when testing to see if it worked. The fluid was milky and garbage, but I don't remember the fluid getting frothy.

Can you describe further how you ran it? Was the direction of flow the same as it is now?
Do you know the rotational direction of the tractor's front shaft? Clockwise or CCW?
Is it possible the noise you hear when using the FEL valve above idle is the pump straining- bad bearing, cavitation, etc?

Is there any problem with pumping straight through the filter?

Only if the filter's particle size is too small and therefore restricts the flow/return to tank.


I used a teflon paste on all new connections. I suppose a tight but not sealed fitting is possible. Would suction show up using soapy water?

I think so, but not sure. I think if there is enough suction, the soapy fluid would be drawn into the site of the leak.


Neither and I I do appreciate all the suggestions. I couldn't get away from other things to work on this today but did have internet access so I've been doing more research than fixing. Hopefully tomorrow. Besides, it's supposed to be warmer tomorrow (high of 19F instead of today's 10F).

I didn't explain the setup at the beginning very well. I was trying not to overwhelm the reader. My apologies.

My setup, for the FEL, doesn't have a strainer. The only thing here that could remove any bits is the filter. I hope that's sufficient. I really don't know.

It might be worthwhile to change it out, to see if it's possibly full of the milky old fluid, which could be contributing to the frothing you're experiencing. And if the current filter is full, then it's not doing any good anyway...

I dithered about the location of the filter but based on this article, I opted for return-line filtration. I suppose I could move this if there's good reason to (like way too much air getting into the system).

I'd hold on moving the location for now, and wait and see if the flow is correct through the entire loop.

Could I have this whole dumb thing plumbed backwards? Looking at the pump (006.pdf above) which side is the high pressure side and which side is the suction?

Refer to earlier questions about rotational direction of tractor shaft, etc.
That's why I suggested earlier to map out with colored tape, the entire flow pattern.
Where was this pump before you attached it to the front shaft? Was it an integral part of the tractor or a complete add on, as far as you know?