Air Leak In Tilt Cylinder Hydraulics?

MtnViewRanch

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Thanks for replying Brian.

I have used the diverter for over a year and it works fine. At least all of the functions work correctly.

I'm not sure what you are suggesting is not the issue. Are you referring to the diverter?

I haven't checked the dipstick but will the next time I use the tractor. Good point and thanks.

I was told by the hydraulic guy at Princess Auto not to use flow restrictors, when I was trying to reduce flows to the tilt cylinder for the FEL brush mower I made. He said something about, when the flow is going into the bottom (large volume) side of the cylinder there is a back pressure created in the ram side which was causing seals to blow in their cylinders. Have you experienced anything like this and does it make sense or not.

What size flow restrictors do you use on Kubota L6060's and do you sell / ship them to Canadians?
I do not believe that air is the issue, unless you have it in the whole system, thus the dipstick fluid check.

When you adjust the cylinders, is it difficult to extend the rod slowly? You have a lot of weight pulling on the rod extending the rod quicker that the fluid can fill the base end when the rod extends very quick. When the base end of the cylinder does not have time to fill, a vacuum is then pulled on the cylinder and you get the spongy rod that you are getting.

I provide 2 flow restrictors 99.9% of the time for each individual top & tilt cylinder I sell. .030 for 2" cylinders, .045 for 2 1/2" dia cylinders and .060 for 3" dia cylinders. Yes the same size for both ends works just fine. No issues with thousands of cylinders provided to date.

I build my own flow restrictors, they are for #6 & or #8 ORB ports with #6 JIC-M ends for connecting the hoses. If you do not have those size-type fittings, then you will probably need to get separate restrictor fittings. When you purchase the separate fittings, they only come in the .030 & .060 orifice sizes.

As far as the check valves for the cylinders, unless you have 3/8" British ports on your cylinders, you will not find a pre-made check valve kit for your cylinders. I have to machine the banjo bolts to be used on my cylinders when I supply check valves for my units as well as make restrictor fittings for the check valve.
 
  
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Hilbilly

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I do not believe that air is the issue, unless you have it in the whole system, thus the dipstick fluid check.

When you adjust the cylinders, is it difficult to extend the rod slowly? You have a lot of weight pulling on the rod extending the rod quicker that the fluid can fill the base end when the rod extends very quick. When the base end of the cylinder does not have time to fill, a vacuum is then pulled on the cylinder and you get the spongy rod that you are getting.

I provide 2 flow restrictors 99.9% of the time for each individual top & tilt cylinder I sell. .030 for 2" cylinders, .045 for 2 1/2" dia cylinders and .060 for 3" dia cylinders. Yes the same size for both ends works just fine. No issues with thousands of cylinders provided to date.

I build my own flow restrictors, they are for #6 & or #8 ORB ports with #6 JIC-M ends for connecting the hoses. If you do not have those size-type fittings, then you will probably need to get separate restrictor fittings. When you purchase the separate fittings, they only come in the .030 & .060 orifice sizes.

As far as the check valves for the cylinders, unless you have 3/8" British ports on your cylinders, you will not find a pre-made check valve kit for your cylinders. I have to machine the banjo bolts to be used on my cylinders when I supply check valves for my units as well as make restrictor fittings for the check valve.
Thanks again Brian.

I played around with the tractor again and found that there was air in the cylinder even after sitting for a while. I could not get all of the air out by pushing and pulling the cylinder to full relief many times. I checked the dip stick after doing this and there was air in the fluid, which I expected since I was hitting the relief pressures many times. So I tried using the rear blade to see if I could get air in the cylinder again but after about 20 minutes of pulling and pushing the rear blade there was no air in the cylinder and no air in the fluid. It appears that the problem doesn't develop until I have used the rear implement for a while and it has been bouncing back and forth between catching and releasing. Does this sound like an issue that the restrictors would solve? The ports on my cylinder are ORBF so I guess the valves SC sells would not work for me. If you think the restrictors would work then I will PM you about getting some.

John
 

MtnViewRanch

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Thanks again Brian.

I played around with the tractor again and found that there was air in the cylinder even after sitting for a while. I could not get all of the air out by pushing and pulling the cylinder to full relief many times. I checked the dip stick after doing this and there was air in the fluid, which I expected since I was hitting the relief pressures many times. So I tried using the rear blade to see if I could get air in the cylinder again but after about 20 minutes of pulling and pushing the rear blade there was no air in the cylinder and no air in the fluid. It appears that the problem doesn't develop until I have used the rear implement for a while and it has been bouncing back and forth between catching and releasing. Does this sound like an issue that the restrictors would solve? The ports on my cylinder are ORBF so I guess the valves SC sells would not work for me. If you think the restrictors would work then I will PM you about getting some.

John
I would say to fully extend and retract the cylinder a minimum of 10 times. DO NOT hold it in relief.

I have seen where it takes more than 10 full cycles to get the cylinder full of oil, typically less than 5 times, but there are always those odd ones.

Then check the dip stick for aeration.

Another issue that I have seen is once everything is up to operation temps, then things open up and actually suck air into the system if indeed that is the issue.

As far as the restrictors, you can get them and install them at either of the hose ends, which ever end works out best.
 
  
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Hilbilly

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I didn't get a chance to use the tractor today but will try cycling the top link as suggested the next time I'm on it.

I think the issue is as you noted about getting everything warmed up. It seems to me that I have no issues using the snowblower on the way down my driveway but when I start coming back up the blower starts bouncing around because the top link is moving. I may get a chance to use the blower in the next few days, if the snow keeps coming like it has been over the last few days.

Thanks for all your help with this. (y)


John
 
  
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Hilbilly

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Today I got some tractor time moving snow around and tried the top link cycling. Before cycling there was about 2" of play in the cylinder and after at least 10 cycles there was about 5" of play. It got worse, not better, which is weird. I went from full extend to full retract and as soon as it hit relief I reversed direction. Afterwards I checked the hydraulic fluid and there was some air in the fluid. Not a lot but some. I also noticed the sir was in the large side of the cylinder (not the ram side). This is really frustrating. If this keeps up I might have to remove the hydraulic top link and go back to a mechanical, at least for using the snow blower, which is heavy.
 

MtnViewRanch

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Today I got some tractor time moving snow around and tried the top link cycling. Before cycling there was about 2" of play in the cylinder and after at least 10 cycles there was about 5" of play. It got worse, not better, which is weird. I went from full extend to full retract and as soon as it hit relief I reversed direction. Afterwards I checked the hydraulic fluid and there was some air in the fluid. Not a lot but some. I also noticed the sir was in the large side of the cylinder (not the ram side). This is really frustrating. If this keeps up I might have to remove the hydraulic top link and go back to a mechanical, at least for using the snow blower, which is heavy.
Is the implement down on the ground when you are actuating the cylinder?
 
  
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Hilbilly

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I start with it in the air but it ends up contacting the ground and pushing into it, when extended.
 

Leejohn

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On my GL there is a rubber hose on the pump intake side on the right side right where goes thru the fire wall. If it gets cracks or pin holes it well suck air and not leak. I'm not sure if the 6060 has a rubber hose.
 

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I have found that I have much better luck getting the free play from a cylinder if I remove the implement so that there is no external forces. I always assumed it was a vacuum building up when the raised load was hanging on top link so when the extend valve was opened the oil flowed back into the tank unrestricted and faster than the pressure side filled. But whatever, I could get rid of the problem faster w/o weight on the cylinder ????

gg
 

MtnViewRanch

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I start with it in the air but it ends up contacting the ground and pushing into it, when extended.
Have the implement on the ground and cycle it 5-10 times. Feather the controls, don't simply pull the lever to full flow.
 
 
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