Slow curl action

[DonRybak]

Early last year I installed the diverter valve sold by Rural King as a kit for my RK37 along with a grapple made by Homestead Implements. Yesterday I removed the grapple and installed a hay spear to move a couple round bales. After spearing the first bale I noticed that the boom lifts fine but the curl action seems slow. The fluid level is fine and I ran the attachment thru full curl/dump several times to eliminate any trapped air but it's still slow. I timed it right at 13 seconds from full dump to full curl. Since the boom lifts fast I'm wondering if maybe the flow is restricted through the diverter valve and just not as noticeable with the grapple. I'll be putting the grapple back on tomorrow and see if I notice it being slow too. Any thoughts?

 

[DonRybak]

Today I removed the hay spear and watched the empty quick attach while doing a dump/curl procedure. Still extremely slow without anything mounted. The with the grapple attached I tried opening/closing the jaws and they function as advertised. Since the jaws and the dump/curl function use the same pressure lines and the jaws work, the only thing I can think of is some obstruction internally in the diverter valve to the dump/curl ports feeding the cylinders or in one of the hydraulic lines between the valve and the cylinders. I guess the next step will be to bypass the valve to see what affect that has. Anyone has any ideas of what to try?

 

[DonRybak]

Haven't done any troubleshooting on the issue due to not using the tractor and the problem not making the tractor non-functional. It's just annoying. Talked with my neighbor who does some tractor work on the side and he said his Kubota did something similar when just a little over a year old and the dealer replaced one of the curl cylinders saying that the internal seal on that cylinder was leaking allowing a portion of the fluid to go around the seal rather than put full pressure on the piston. Like I said previously the grapple jaws function perfectly so his suggestion makes sense. Rather than pulling both cylinders to have them tested at a shop I'm wondering if I raise the bucket off the ground and curl it up then disconnect one of the cylinders from the quick attach, wouldn't the bucket slowly droop down if the cylinder was allowing the fluid to leak past? If it didn't droop down then I could reconnect the cylinder and try the same thing on the other side. The closest shop I found a reference to is about 25 miles away so trying to avoid having to pull them to find out that's not the problem. Any thoughts or suggestions?

 

[Harry in Ky]

So the problem you have is the bucket curl cylinders work as you feel they should (extend, retract, hold weight) without issue, they just seem to be operating too slowly? The grapple seems to operate as fast as you would expect? This "slow action" appeared after you installed a diverter valve? What valve would that be, and are you SURE it doesn't include some sort of restrictor fittings somewhere intended to slow down the action? Just guessing here, but I would expect the grapple cylinders are smaller diameter than the bucket cylinders and should be expected to travel faster.

 

[DonRybak]

Thanks for the reply Harry. You are correct that the curl function works as it should except slow. The loaded manual says the bucket should curl in 5.2 seconds. Mine takes about 17 seconds as close as I can time it with my watch. I agree the grapple cylinders should be faster due to size. The diverter valve has been installed for over a year and there's been no issue until a few weeks ago so I don't think that's the issue unless there's a restriction inside it.

 

[Harry in Ky]

Well, I'm not sure an internal problem with cylinder piston seals would cause that without some other symptoms going along with it. If the cylinder action is suddenly slower than usual it's more likely the flow in and out has reduced for whatever reason. The new valve you installed is the first place to suspect an issue. If nothing obvious jumps out at you, I would probably just disconnect the hoses from it, hook them back up as they were before it was installed and see what happens. If the problem is still there that's one thing. If it's gone, then the valve has got to be involved.

 

[DonRybak]

I mentioned in my second post that I thought maybe bypassing the valve would be an troubleshooting option. I stupidly ditched the original hoses after installing the valve so I'll probably have to purchase a couple or maybe a couple fitting to just connect them together.

 

[oldnslo]

Is this a new problem to a system that was working fine? Diverter valves can get debris in them causing a partial shift so would possibly start there. If you run tractor at idle are speeds close to what you would expect?

 

[Jrasband]

Are the rods bent?

 

[DonRybak]

Thanks for the views and replies. I have an update... Last night laying in bed I wondered to myself "Rather than starting to disconnect lines why don't I just swap the dump/curl lines with the up and down boom lines at the control valve?" Well this morning I did just that and of course the joystick works different but with the lines swapped the curl/dump function works perfectly but now the lift function is very slow. That eliminates any problem with the diverter valve. I'm now thinking maybe something has became lose on the bottom of the joystick. I'll have to pull the kick panel and see if there's something obvious with the linkage. If it's not there then about the only other thing in play is the control valve itself.