Hydraulic Help Please

[Ice Man]

First, I have a complaint. I started reading this board about 3 months ago and I am just addicted. Yes addicted. I have learned a bunch from you all and I have a bunch more to learn. Well I guess admitting that I have a problem is the first step to something or other.

I am also new to all of this tractor stuff having bought my first tractor (JD 4510) about the same time I found this place – so my question may seem very obvious to some, but I wouldn’t ask if I knew – so I appreciate your patience with me.

I have some hydraulic questions that started from my effort of placing grapple-like thumb on my FEL. The brand is The Thumb.

My problem is I cannot get the grapple hydraulic cylinder to work. If I mess with it I can get it to retract, but I cannot get it extend under power. It will fall (extend) under the weight of the thumb. When that happens I can grab the grapple and lift it up by hand easily. I can also get it to react erratically going in a bit, or out a bit and not always based on the correct direction of the joy stick.

So I researched this site and I found many references to quick disconnect problems. (My basic setup is like many folks have done here. Fasse diverter valve from my dump/curl spool - hoses to the front fel-mounted quick disconnects – short hoses to grapple single cylinder.

So in trying to troubleshoot this, last night I disconnected every thing (fasse valve – extended hoses to the front etc.) and connected the grapple cylinder directly to the tractors curl spool and then to the dump spool. Same results. Then I swapped the quick disconnects and replugged them directly into each of the tractors spools again. No changes.

I spent half a day searching here from something else to try. But I found nothing new. I am lost.

So what do you think?

One thing, the cylinder is new (it came with the grapple). Is it bad maybe?

I also have a basic hydraulic question which I thought I knew the answer to before I started this but am now doubting my understanding. Is it true that a normal cylinder hook up works like this: When extending the cylinder – oil pressure increases on base(bottom) side of the cylinder and reduces pressure on the top (ram side) Also the low pressure side returns oil to the tractor . And when the cylinder is retracted the reverse happens. True?

Thanks and sorry about the length of my question. I always see a lot of newby’s question get the first response being we need more info.

- Dave

 

[SFish]

Ice:

I am not familiar with your tractor model. On my 3320 I had a similar problem when I first hooked up my grapple. I read the manual and found that the regeneration function (allows quick dump of the bucket) was the problem. When using the grapple I turn this off. On my tractor the control lever has 3 positions- Top= unlocked (regen on), middle= normal function without regen, and bottom= nothing works (for safety, e.g. grandkids on the tractor).

Steve

 

[kennyd]

Welcome to TBN IceMan

I think Steve hit the nail on the head here, but to be sure try plugging the grapple cylinder into the lift/lower spool and see if the cylinder works.

Read this POST to get a excellent explanation of the REGEN feature, and why it's messing you up!

Please let me know if I can help more...

 

[Ice Man]

First off, thanks Steve and Kenny. Your input has me further down the troubleshooting path. I learned some more too. You’re great.

As Steve suggested I (tried to) shut off the regen for the FEL spools. I have the same setup as Steve described and though I placed the regen control in the mid-location to shut it off - It didn’t correct the problem I was seeing. Yet I was still sure that Steve had it right. What I did to continue testing is I picked up two fittings to connect the cylinder to the 3rd SCV already installed on the back. The cylinder worked perfect from the rear and I am fairly sure the rear doesn’t have regen. So Cylinder works. That’s good.

So now I think we have the problem narrowed down to the regen control not working right. I would really appreciate any suggestions on how to attack this problem if anyone has ideas. Is there a linkage issue maybe?

Thanks again. - Dave

 

[SFish]

Dave:

I have been thinking through your original post and have a couple of questions. Basically, the behavior that your grapple shows should be mimicked by the bucket curl. By doing the following with regen on and off, and the diverter out of the circuit, you can be sure that the problem is with the regen control.

If the grapple just falls down without any force on lower, can you put the bucket on the ground and curl it down so that it lifts the front of the tractor?

Similarly, if you can lift the grapple by hand does the lowered bucked curl up without resistance when you lower the main boom to the ground?

You stated that you had to "mess with" the control to get the grapple to retract. Is this also the case for curling the bucket up?

Once sure that the problem is the regen control then someone here might know what to try next (I don't), or you will have to call the service manager at a dealer.

Steve