3rd function was installed by dealer at time of purchase. Two buttons to open/close grapple. Grapple opens and closes as it should, just issue with curl/dump. Some bubbles in hyd fluid after running, but wouldn't call it 'foam'. Dealer said that shouldn't be an issue, but that was not in the context of a discussion about the problem I'm discussing. Just a question I'd asked him. Not aware of a 'cleanable' hyd filter. Will be running this weekend and try to pay closer attention to what's going on. How do you go about finding a suction leak? Can I bleed the bucket cylinders?
I understand that when running a shredder, I need to keep rpm up for proper rotational speed. That being said, is it okay to run at lower rpm to attempt to compensate for bucket jerkiness until I come up with a permanent solution? Will it even help. I realize that lower rpm will make everything run slower, but can it do any damage? For instance if I'm lifting a load of dirt in the bucket, will it hurt anything to run at lower rpm, or just make raising and lowering slower? I do understand that at lower rpm, I won't have the same amount of torque/power when I'm pushing into the dirt pile so could raise rpm to fill bucket, and then back off to lift, dump, etc. I still consider myself a newbie, so not sure if that makes sense or not. Thanks all.
Well, then from what you are describing it's probably not a suction leak. Rule of thumb is that a few bubbles don't count. If a suction leak isn't sucking enough air to notice some foam on the hydraulic fluid while the tractor is running, it probably isn't causing your problem. Foam does go away anywhere from ten minutes to overnight after shutting down - depends on the fluid type and how much condensation is in the fluid.
To answer your question on how to find a suction leak....well, it's difficult. The problem is that a suction leak is a leak where air is going in, but maybe no oil comes out. And it only happens when it is running, Foamy fluid is a clue, but that goes away half an hour after you shut it down.
The way I find a suction leak so far has been almost by accident. What happens is that I am under the tractor and notice that the outside cover of a suction hose or fitting is getting oily. and dirty. It can do that for a long time and not even cause a problem running. But finally it will begin to wet the undercarriage and
may even begin to drip a bit overnight. That is diagnostic because the outside of those suction side hoses and fittings should be dry.... not have any oil on it at all.
Regarding bleeding the system: It's an open hydraulic system. The hydraulic/transmission common sump is open to the atmosphere via a vent. Most loaders will bleed themselves in 5 minutes or less once the fluid gets warm if you waggle the bucket and lift up and down a few times. Hydraulic fluid traps and removes the air which is then vented out the sump.
It could still be a plugged hydraulic filter - especially the cleanable one if it has that. Ask the dealer about it.
But if it were a plugged filter it would be causing the same problem throughout the whole hydraulic system - including the 3pt lift and sometimes the power steering.
Lots of guys run the PTO slower than rated speed. I'm one of them. I've never heard of it causing a problem as long as you are making enough HP to keep the temperature down. But I am careful to listen carefully when I run slowly. I want to keep rotation smooth....to make sure that things are still rotating nicely. If anything on the PTO or implment starts to shake or rattle, that is WAY too slow. Speed it up... but that is the same on any machine anywhere.
As far as the FEL and gapple go, you can use them at an idle if you want. It won't hurt a thing. Some tractors want high RPMs because that is where their emissions control systems work most efficiently, but as far as hydraulics go you can run the FEL fine with the motor on low idle.
Frankly, as you look around on TBN I think you will find that not all 3rd functions and grapples work smoothly with bucket curl. Mine does - but that is partly luck of the installation. Here on TBN we all hear about others that do not work smoothly. Some even have "crosstalk". You have already got some advice about adding variable flow restricting devices. I think that is good advice and you may end up doing that. Just be careful with it; any flow restriction is a high pressure point. You want to make sure that any place where you put restriction is a circuit protected by a relief valve. Most are, but check.
A lot of the time I suspect that an irratic grapple/3rd function/bucket curl it is in the way that the plumbing of the "power beyond" and the "return line" was done for the 3rd function install. Give some though to that and even ask the dealer if this is his custom install or a factory kit.
A return line should be absolutely without restriction. It should have flow velocity, but not pressure. Multiple valves can use the same return line, but it sometimes needs to be slightly larger diameter. Best practice is to "Y" into a return line rather than using a "T".
Sounds to me like you are on the right track. So far I'm not hearing anything worrysome. Just a problem to be addressed. No red flags.
rScotty
