Problems on home built FEL

[Gary Sweat]

I have been out learning how to use the loader and testing it. Everything with the loader seems to be working alright but two things have shown up that I didn't expect. Tractor is a YM1900.

1) Hydraulic oil from the transmission is seeping out around the shifter boot. I am assuming it is being caused by the return adapter I made in order to route the loader valve tank port back to the transmission. Since I never had this problem before I put the loader return line into the oil fill hole, I'm pretty sure it is the cause. Not sure why or how to stop it. (See photos of the adapter)

2) When dumping a full bucket of dirt, the bucket will speed up once it passes the break over point. Then it will take a few seconds before I can move it further down. I am guessing it is creating a vacuum in the cylinder and the pump can't keep up with the flow rate going out. I am reasonably sure this is not a good thing and could use some help or ideas on how to correct it.

 

[kennyd]

I have been out learning how to use the loader and testing it. Everything with the loader seems to be working alright but two things have shown up that I didn't expect. Tractor is a YM1900.

1) Hydraulic oil from the transmission is seeping out around the shifter boot. I am assuming it is being caused by the return adapter I made in order to route the loader valve tank port back to the transmission. Since I never had this problem before I put the loader return line into the oil fill hole, I'm pretty sure it is the cause. Not sure why or how to stop it. (See photos of the adapter)

2) When dumping a full bucket of dirt, the bucket will speed up once it passes the break over point. Then it will take a few seconds before I can move it further down. I am guessing it is creating a vacuum in the cylinder and the pump can't keep up with the flow rate going out. I am reasonably sure this is not a good thing and could use some help or ideas on how to correct it.

Can't help with #1.

#2-Can you refresh my memory...what valve did you use? It sounds like you are in the regen (regenerative) position on it.

 

[Gary Sweat]

The valve is from Baileynet PN 220-910 and as far as I know does not have regen capability. It's just a straight forward 2 spool, 4 position valve. I could be wrong but I don't remember anything being said about regenerative capability when I bought it. I'm concerned about it possibly creating a vacuum in the cylinder and eventually sucking air into the system past the seals.

 

[wdchyd]

Gary'

#1.....? Is the trans case/reservoir vented..?...it maybe venting thru the rubber boot.....the adapter fittings are very creative, nice work.....would like to see a piece of tubing incorporated in it to deliver the return oil below the oil level to alleviate turbulence at the fitting creating air/foam.......

#2.......Possibly overrunning load creating suction in hyd lines (pump flow slower than load inertia)......flow control may help...Parker F600S Flow Control Valve.....

Hope this helps....

 

[Gary Sweat]

Gary'

#1.....? Is the trans case/reservoir vented..?...it maybe venting thru the rubber boot.....the adapter fittings are very creative, nice work.....would like to see a piece of tubing incorporated in it to deliver the return oil below the oil level to alleviate turbulence at the fitting creating air/foam.......

#2.......Possibly overrunning load creating suction in hyd lines (pump flow slower than load inertia)......flow control may help...Parker F600S Flow Control Valve.....

Hope this helps....

#1... I can add a tube extension as I don't see anything directly below the opening down to the oil level in the transmission. The only vent that I am aware of sits on top of the 3pt assembly. It's a small curved tube. I have not checked to see if dirt dobber's have plugged it up. We have a problem with them here in Oklahoma.

#2... The pump on this tractor only puts out 4gpm which works the loader well enough but may be the problem as you suggest. Would I be able to put the flow control valve in just the bucket lines? The loader goes up and down just fine and a full load does not have the same effect on those cylinders. I don't know enough about hydraulics yet to understand exactly what is going on but I don't like it

 

[wdchyd]

Yes, you can add a flow control valve in just one of the circuits(metering the hyd oil as it comes out of your tilt cyls, ie: meter out) the valve has an adjustment for one way(tilting down) and unrestricted the other direction(tilting up).....

Only one would be installed between the FEL control valve and the tee that splits to the tilt cyls (rod end).....a great valve for tuning and tweaking.....

 

[PILOON]

Wondering if the speed up at breaking point might not be caused by some air lock in the cylinders?

I know that cycling cylinders generally purges things but depending on hose placement there always could be possibility of some 'air lock' in there.

Might try cracking the fittings on the tilt cylinders to bleed out any air.
ie; when fully retracted crack the bottom end fitting and when extended crack the rod end fitting.
A show of bubbles will prove the point.
Either way, nothing to lose. (maybe couple ounces of fluid)

Good luck!

Suggest that placing some rugged object under the bucket and using down pressure til reaching full retraction before bleeding otherwise you'll let in more air and the object is to compress the cylinder fully to force out oir.

Kinda like bleeding brakes on a car.

 

[jlsmith]

Hey Gary, like another member said add a line where u installed the return to go fuller into the trans. This should stop the leak and cut down on the air bubbles which is not good to have in the oil.

 

[Gary Sweat]

Yes, you can add a flow control valve in just one of the circuits(metering the hyd oil as it comes out of your tilt cyls, ie: meter out) the valve has an adjustment for one way(tilting down) and unrestricted the other direction(tilting up).....

Only one would be installed between the FEL control valve and the tee that splits to the tilt cyls (rod end).....a great valve for tuning and tweaking.....

Thanks, I'll order the valve and see if that cures the problem. If I only push the bucket lever about half way to lower the bucket, the bucket will go down ok and doesn't cause the delay in getting it to move again but that is aggravating trying to get just the right position on the lever.

 

[Gary Sweat]

Wondering if the speed up at breaking point might not be caused by some air lock in the cylinders?

I know that cycling cylinders generally purges things but depending on hose placement there always could be possibility of some 'air lock' in there.

Might try cracking the fittings on the tilt cylinders to bleed out any air.
ie; when fully retracted crack the bottom end fitting and when extended crack the rod end fitting.
A show of bubbles will prove the point.
Either way, nothing to lose. (maybe couple ounces of fluid)

Good luck!

Suggest that placing some rugged object under the bucket and using down pressure til reaching full retraction before bleeding otherwise you'll let in more air and the object is to compress the cylinder fully to force out oir.

Kinda like bleeding brakes on a car.

I'll try your suggestion tomorrow. Maybe it is just air. I had to cycle the cylinders the very first time about a dozen or more times until I could stand on the bucket without it moving a fraction of an inch or so. I've been concerned about how to get all of the air out of the lines and maybe this will work. The bucket will raise the tractor off the ground without hesitation but that may not mean there isn't still air in the lines.

 

[Gary Sweat]

Hey Gary, like another member said add a line where u installed the return to go fuller into the trans. This should stop the leak and cut down on the air bubbles which is not good to have in the oil.

I guess I will have to make a new piece that is longer. I thought about just threading the inside and screwing an extension on it but the idea of it coming out and falling into the tranny is a little unnerving. I'm sure there are ways to lock the threads against that but it would always be on my mind that it could happen. I'll let everyone know if that cures the problem.

Thanks guy's for the suggestions.

 

[wdchyd]

Gary,

That link I gave you may not be the best place to buy the valve, I used it only for the picture and description......there are other brands out there just get the type that is adjustable in one direction and unrestricted in the other.....don't be confused with a normal needle valve (restricted in both directions)......they are available in whatever size your hoses are (1/4", 3/8"ect)..........

 

[Jay4200]

Gary,

That link I gave you may not be the best place to buy the valve, I used it only for the picture and description......there are other brands out there just get the type that is adjustable in one direction and unrestricted in the other.....don't be confused with a normal needle valve (restricted in both directions)......they are available in whatever size your hoses are (1/4", 3/8"ect)..........

Here's one for about half the dough - I think it's the same:

https://www.surpluscenter.com/item.asp?item=9-5300-38&catname=

JayC

 

[Gary Sweat]

Here's one for about half the dough - I think it's the same:

https://www.surpluscenter.com/item.asp?item=9-5300-38&catname=

JayC

Thanks for that link. I took a quick look at Baileynet and they want $40.00 for the same style valve. I do have a question about the gpm rating on the valve.
Should I select one that is close to my pump gpm of 4 gpm or does it matter?

 

[wdchyd]

Just use the same size approx as your hose coming out of your work port from the valve

 

[Gary Sweat]

Just use the same size approx as your hose coming out of your work port from the valve

Thanks, I'm ordering one today and should have it around the middle of next week. I'll let you know if that solves the problem.

 

[Gary Sweat]

Ok, I found something else I am not sure about.

With a full bucket of damp dirt, the gauge shows 750 -800 lbs pressure max. The 3 pt with a 4' bush hog shows about 800 lbs lifted all the way up. The loader relief valve is set from the factory at 2200 lbs. Should I lower this reading to something closer to the working load of the implements or just leave it where it is? It will hit the 2200 lbs real fast when the cylinders reach max travel.

 

[wdchyd]

It wouldn't hurt to back the PRV down to a manageable setting till you feel comfortable about your setup......running up to 2200 psi at end of stroke is Ok and won't hurt anything......

The mechanical integrity of your structure/frame/weight balance is what I be worried about......the hydraulics will be just fine.....a pressure guage somewhere visible when operating might make you feel more confident of the proper pressure setting.....

 

[Gary Sweat]

It wouldn't hurt to back the PRV down to a manageable setting till you feel comfortable about your setup......running up to 2200 psi at end of stroke is Ok and won't hurt anything......

The mechanical integrity of your structure/frame/weight balance is what I be worried about......the hydraulics will be just fine.....a pressure guage somewhere visible when operating might make you feel more confident of the proper pressure setting.....

Thanks for bringing up the issue of the mechanical integrity. I built the loader and bucket to a size I hoped wouldn't be a strain on the tractor. I'm not an engineer so I don't know how to calculate what would be a safe working load. I built the loader using the PF Engineering plans for a SCUT and modified them a little to fit my YM1900 hoping that if a SCUT could handle that size bucket, then my tractor should be ok.

I don't know what I should lower the PRV to for a safety margin or how to calculate a safe working load. If anyone has any experience with this, I could really use the help. Thanks.

 

[AKKAMAAN]

I don't know what I should lower the PRV to for a safety margin or how to calculate a safe working load. If anyone has any experience with this, I could really use the help. Thanks.

As long as cylinder is rated for the set PRV pressure and cylinder is taking all the stress from stalling, your current setting should be fine. But if you grab a very heavy load, you might stress the structure. To fully protect the structural integrity, I would advice a work port PRV, set at whatever 700-900psi. That would protect the structural integrity, if you travel/move, bouncing, over uneven ground with a heavy load in the bucket, as well as protect from excessive pump pressure. This way you also have your 2200psi available for a future PB application