Help! Curl cylinders acting up

[kennyd]

The valves are new.

What valve do you have Mike?

If the load in the bucket is causing the fluid to pass through the cylinder faster than my pump can make up the difference, wouldn't that indicate a bad valve?

No, not at all.

Should I move my curl hoses over to the grapple valve position and try it there?

Sure, you have nothing to loose.

I have talked to several buddies that have loaders on their tractors, and they all say that in the curl up function, that either you will bend your bucket or pick up the rear end of your tractor.

Any truth to these?

Generally true. Do you know the specs for your machine (PSI and GPM)? Has the relief valve on the new valve beeen set to match the tractor?

 

[J_J]

A 3000 psi hyd gage would help solve most of your hyd problem. It will tell you if you have pressure and how much, and and allow adjusting of the relief valve. Install the gage at the IN port of the FEL valve.

 

[AKKAMAAN]

Maybe I should try swapping the curl hoses over to the grapple valve to see if that solves the problem.

Absolutely

If the load in the bucket is causing the fluid to pass through the cylinder faster than my pump can make up the difference, wouldn't that indicate a bad valve?

No, it just indicate the bucket is curling (dumping) faster than the pump can keep up with. If valve is new it can be assumed not being bad (as broke), but it can be "wrong spool" in the valve, spool for a single action function (power up, gravity down). If so, that function (spool) could meant to be for the FEL lift, or another aux function.....
Who provided the valve? A link to this valve available, or post valve make and all valve numbers....

I have talked to several buddies that have loaders on their tractors, and they all say that in the curl up function, that either you will bend your bucket or pick up the rear end of your tractor.

Any truth to these?

If pressure relief valve is properly set, it will relief before any damages happen. The bucket curl can not lift the rear end of tractor, but the FEL lift arms could, but that is not a preferred or common set up.

Should I move my curl hoses over to the grapple valve position and try it there?

Yes

 

[J_J]

Assuming flow at 10 GPM's, and 2 in bore, with 1 in shaft, the flow out the rod end will be around 30 GPM's

Pump flow plus regen flow would be around 40 GPM's. If this is true, you can see that a good load will generate more flow than the pump is pumping

Retraction flow, base end would be around 13.33 GPM's

What valve are you using, GPM capability, relief setting, etc.

As far as lift circuit leaking or curl circuit leaking, all valve spools have a drops per minutes leak rate. Some will stay up for months, and others you can watch them leak down. Depends on what you can live with. Shut off valves can help with some of that.

 

[Egon]

Seeing as everything was cleaned out maybe check out the cylinder bores as previously noted.

 

[wdchyd]

Seeing as everything was cleaned out maybe check out the cylinder bores as previously noted.

x 2


Seen this many times were the bores were scored but the cyl gets repacked anyways........especially the newer style cyls, the bores need to look almost perfect and smooth when they go back together.....some guys hone out the bore too rough thinking the bores will break in like an engine.....WRONG..!!

like others have said, pressure guages to rule out components will help by process of elimination.....:thumbsup:

 

[BayouMan]

OK guys,
There is a lot of information coming at me and I don't understand half of it. I went and looked at the 3 spool set-up on my tractor. I didn't see any identifying information. I'll have to call the shop guy and see if he has that information. It cost about $420 at the time.

I'll take some pictures of the spools later tomorrow. Got company (Grandson) coming by today. I'm not sure if it will be tricky or not to swap the hoses around. Looks like two different fittings were used.

If I can get BIL to help, I'll get him to video and see if I can capture the stall on dumping.

The leak down rate is not even close to acceptable. You can literally watch the curl leak down. Not good when you are trying to position something by yourself.

 

[dcyrilc]

OK guys,
There is a lot of information coming at me and I don't understand half of it.

If you need to. Take it in pieces and ask specific questions. That way we can give specific answers to help you to understand everything.

 

[TTTTTT]

I have a similar problem, but don't want to hijack the thread. May be resolving mine will help BayouMan. I have curl cylinders that also appear to have leak down. They will drop without any load on and quicker with a load. The main loader stays up with no problem. Including with engine off with no hydraulic pumping hydraulic flow. If I keep the revs up and constantly hold the curl up function on the joystick control I guess the increased flow will overcome the apparent leak down and hold the load (bucket curled) up. I switched the hoses to have the sideways joystick movement operates main loader and up/down on the joystick operates the curl function. Still have the exact problem of the curl leaking down. Returned the hoses to original setup with curl leak down.

The obvious answer is the curl cylinder seals are not holding and fluid is bypassing. The question is, do you assume both cylinders leaking, and if only one is, why wouldn't the other curl cylinder hold the curl up steady. Or do you just rebuild both and take the guessing out of the picture.

Am I missing anything or is it as obvious as it looks.

thx Dave

 

[wdchyd]

The obvious answer is the curl cylinder seals are not holding and fluid is bypassing. The question is, do you assume both cylinders leaking, and if only one is, why wouldn't the other curl cylinder hold the curl up steady. Or do you just rebuild both and take the guessing out of the picture.

Am I missing anything or is it as obvious as it looks.

thx Dave

It is as obvious as it looks......you did your homework, now proceed to the head of the class and repack those cyls.......

Only takes one bad cyl to make both in that same circuit to creepdown.....the best way is to do both cuz they both have the same amount of wear on them and you'll regret not doing them both.....that said some guys will figure out which one is bad first, then repack it make sure it is good, then proceed to number two to finish the job......DONE......:thumbsup: