B7100 loader (B1630C) issue

[Hotmetal]

I completed step one to rebuild the control valve. It did not have any effect on the problem. Bucket acted exactly the same, which is dumping it's load in about 30 seconds. I had hopes because when disassembling, I found the cap on the back of the bucket spool loose. I thought it might not be centering properly as a result. I thought not centering in the wrong direction could effect the bucket dropping so fast, but it was not to be. One screw was buggered and I had to run a tap into the threads and use new screws. I think lower outside temperature might have effected my test results and given me a false result. It seemed to point toward the control being the issue. The rebuild was easy to do, but, now after the fact, I confess I don't see how replacing these seals would effect leak down unless your control is leaking externally which mine wasn't. All the seals I replaced only seem to deal with preventing external leaks and not directing flow within the valve. I am probably missing something as this is all new to me. I still am waiting on the bucket cylinder kits to arrive for step two. I will report back results after I complete rebuilding them. I must say, working on a tractor is a lot easier than a car. Most things have a lot more room to work and you don't have to remove five things to get at the one you want. I do wish this was happening with temps above freezing however.

 

[CJN8]

Keep after it. I think what you will find is that your piston o-rings inside your hydraulic cylinders are badly worn and bypassing fluid. That was the case for me.

 

[Lil Foot]

Keep after it. I think what you will find is that your piston o-rings inside your hydraulic cylinders are badly worn and bypassing fluid. That was the case for me.

Or full of rust & dirt like mine.

 

[North Idaho Wolfman]

I must say, working on a tractor is a lot easier than a car. Most things have a lot more room to work and you don't have to remove five things to get at the one you want.

You clearly have not dove into the tractor repair pool on the deep end!
All of this for one D-ring seal.

On the Loader Valve repair side of things, a tiny internal crack in the housing can cause the problems you have are having.
Don't spend a ton of time on it, if it won't go away buy a new Spool valve and scrap the old one.

 

[ShaunBlake]

All of this for one D-ring seal.

<mournful sigh> I see I'm going to have to invest a lot more in this money muncher! Now I realize that I have to get some high-tech fixed and resizeable stands/supports. Oh, woe!

 

[Hotmetal]

You clearly have not dove into the tractor repair pool on the deep end!
All of this for one D-ring seal.

On the Loader Valve repair side of things, a tiny internal crack in the housing can cause the problems you have are having.
Don't spend a ton of time on it, if it won't go away buy a new Spool valve and scrap the old one.

Wow, I stand corrected. That certainly doesn't fall under the easy to work on theory. I'm just so used to leaning awkwardly getting my knuckles bloody turning something I can't see on my Saabs that this first job on the tractor control was quite a pleasure.

I will rebuild the bucket cylinders and if that doesn't correct the problem I'll replace the control as you suggest. I am going to swap the hoses again per your earlier suggestion for diagnosis while waiting for the cylinder kits. I want to do a much more thorough test this time. As you pointed out, it should give a clear indication on where the trouble lies.

 

[Hotmetal]

I am back working on my loader issue now that the cycle of winter storms seem to be over.(I hope)

As a reminder, my problem was/is the bucket uncurls and drops it's load in about 30 seconds. I rebuilt the control valve with no change. I purchased the cylinder rebuild kits but have not installed yet.(because it snowed every three days for the last month) Today with the bucket off for rehab, I decided to try swapping the hoses again to see if I could absolutely confirm it was the cylinders leaking. The results just leave me scratching my head. I thought the controls should just be reversed. The spool that controlled the boom would now be the bucket, and the spool that controlled the bucket would now be the boom. Yes, they do control the opposite function, but, why would the boom only elevate no matter whether the proper spool is pushed or pulled? I cannot get it to go down. It powers up with the control in either direction. The bucket cylinders operate normally. When the control valve is hooked up correctly, I can operate the bucket normally. Why not the boom when switched? It's just hooked to two different cylinders. Am I missing something obvious? I can't diagnose the leak problem properly when I can't cycle the loader to get the air out of the system. I have a joystick control for what it's worth.

 

[North Idaho Wolfman]

First shut the tractor off and move the lever to releile all the pressure and drop the loader, swap the 2 lines to the lift cylinders and try again.
If you have a newer style of valve the lines backwards will cause some odd results.
Does it have Quick disconnects on the loader lines?
If it does you could have a bad/ plugged disconnect, they will cause all sorts of odd problems.

 

[Hotmetal]

Hi Wolfman,

Thanks for the reply. I greatly appreciate the time you take to help. I will be working on it again tomorrow and will try your suggestion.

I did already find I could lower the loader by cycling the control when off. I believe it is the original valve from 1995 and does not have quick disconnects.

I know I did not swap the lines improperly, but, I will try changing them. Your suggestion got me wondering how mine are plumbed. I do understand the two ports from each spool attach to different ends of the cylinders to actuate them. But, the adjacent ports from each spool(side by side) go to different ends of the cylinders. I am wondering if that is normal. In other words, the two ports closest to the control stick that operate one direction of the lift and bucket are attached to opposite ends of the cylinders they control. The hose for the lift are attached to the solid/fixed end of the cylinders and the and the hose for the bucket is attached near the ram/moveable end. The two ports farthest away from the control stick obviously are the opposite. It says to me, if I had separate control sticks and pulled both of them, lift cylinders would increase in length and bucket cylinders decrease in length. Does this matter to the control, or is it just for operator convenience and a more natural way for the hand to work the control and therefore the loader? I hope this makes sense.

 

[North Idaho Wolfman]

Yes the configuration of the lines is to make the loader control work in a certain fashion.
Normal loader control is:
Up on control is down on arms
Down on control is Up on arms
Right on control is roll forward/Dump
Left on control is roll backwards/Fill

 

[Hotmetal]

Success!!! Wolfman, thanks for all your help and that goes for the others that contributed as well. I am attaching a photo of a new T seal compared to what I found on the pistons of my bucket cylinders. The top one is of course the new one. The middle and bottom are barely recognizable as being the same seal, but, they are. To me, it is a wonder the bucket even responded to the control. The inside of the cylinder and the piston were not scored which is also amazing to me. Once I had the right tools, I found the job was quite easy. I also found it easier to work with the cylinder on the tractor as it holds it so well without harming anything. Oh, and due to the design of the internal wire holding mechanism, it is best not to pull the gland out after inserting to see if the new o rings went in ok. It is likely you will destroy them when removing the gland as there is a sharp edge that comes into play only when removing the gland. Insert it with the new o rings and leave it. Fortunately, it was only a $1.65 mistake, but, delayed the job by an hour to retrieve new ones.