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Discussion Starter · #21 · (Edited)
Info update

Had some time this afternoon to run a few tests. Here's what I found:

When I switched the boom and bucket hydraulic lines, the boom will lift and hold the tractor up. So the issue seems to be in the SCV boom down valve. I also noticed that while they were switched, when I raised the boom, and then curled the bucket, it (the empty bucket) would start to dump. That wouold be the valve that is normally for the boom.

When I switched the lines back, I did the test again. And at first, it also held the trator up, and I was thinking what the heck is going on, it's working. Then I put the bucket and boom to both extremes, and held for several seconds each end of travel, to feel sure that any trapped air would bleed out. After I did that, I lifted the front axle up again, and it dropped right back down in just 2 or 3 seconds. Now I am even more perplexed...

But I noticed that as the tractor went back down, that the tractor was also moving (none of the previous tests had the brake set. So I held my foot on the brake, and lifted the front end again. Now it will stay there. Remove my foot from the brake, and it lowers the tractor as it rolls the tractor backwards.

Should I expect the boom to hold the front end up whether the brake is set or not?

I also tested the hydraulic pressure at the port for the boom down line, and it was 2300 psi. Don't know if that is the way to test it, but at least I know that at 2100 rpm, I have 2300 psi when the SCV valve is held down.

I did try to see if the SCV valve was returning to neutral, or overshooting and going slightly past it to raise the boom. It did not appear to, but I will check it more closely tomorrow.

Thanks for all the suggestions.

Auto part Vehicle

This is how I plumbed up the fittings today.

Green Water Gauge Tire Automotive wheel system

PSI at 2100 rpm, with gauge in-line with Fel. I did not do a dead-head test yet.

Product Water Material property Lubricant Tire

This is the hydraulic fluid that I have in the tractor. In the print at the bottom, it lists as meeting the specs of John Deere, and is compatible with both synthetic and regular hydraulic.
 

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Discussion Starter · #23 ·
Will,

Just curious as to how you are making out, or if you have opened up any of your other cylinders yet?

Clint,

I haven't done the left bucket curl cylinder rebuild yet, but I will do that next. It's leaking from around the outer seal. Assuming that if the front wheels are pushed up off the ground with the boom control, they should stay up whether the brake is on or not, then I still have a problem. If I set the brake (or press on the brake pedal), raise the front end up, and relax the joystick, it will remain up (for the short time I tested it that way).

I wanted to get back out there this weekend, and do some more checking, but this weeked took a different turn, and I have been busy with unplanned activities... that's life.

I'll probably get to that either tomorrow or Tuesday. I'm pretty sure, at this point, that the SCV valve isn't holding pressure, when in the neutral position. But I do want to verify. I have been told that the SCV cannot be serviced, and if there is any valve problems with it, that the whole assembly would need to be replaced. That sounds expensive, so if it's that, I will probably just have to live with it.

Clint, thanks again for your help on the phone, and for the parts.
 

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Discussion Starter · #24 ·
Well, in my post above, I mentioned that somebody told me the SCV valve was expensive. In fact, I remember them saying that it was somewhere in the neighborhood of $700~. So yesterday, I drove the hour drive to the local Deere dealer, to find out first hand, and I did.

It is not $700, or anywhere near that. The price of the SCV valve block for a 4100 tractor is....
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.
...........drum roll please.....
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...........(fasten your seatbelt)
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That part, which they have in stock :yahoo: is only $1882.00 :laugh:

and they will still have it in stock tomorrow, and next week, and next month, and probably next year...

cause I ain't buyin it, and I'm thinking nobody else it either. :lol:
 

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Well, in my post above, I mentioned that somebody told me the SCV valve was expensive. In fact, I remember them saying that it was somewhere in the neighborhood of $700~. So yesterday, I drove the hour drive to the local Deere dealer, to find out first hand, and I did.

It is not $700, or anywhere near that. The price of the SCV valve block for a 4100 tractor is....
.
.
.
.
...........drum roll please.....
.
.
.
.
.
...........(fasten your seatbelt)
.
.
.
.
.
That part, which they have in stock :yahoo: is only $1882.00 :laugh:

and they will still have it in stock tomorrow, and next week, and next month, and probably next year...

cause I ain't buyin it, and I'm thinking nobody else it either. :lol:
:lol:so ur saying ur gonna run ur tractor the way it is:munch:
 
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Discussion Starter · #26 ·
:lol:so ur saying ur gonna run ur tractor the way it is:munch:
BigJim,

The answer to that question is more than a yes or no. I am not 100% convinced that the SCV is actually the problem, since it is *possible* that an internally leaking boom cylinder seal could hold pressure better one way, (lifting), and not so good the other, (pushing down). The seal on the piston does have a taper to it, which is oriented to seal better when lifting. So I will rebuild the boom cylinders first, to eliminate that.

Since the loader functions perfectly well in all regards except lifting and holding the front wheels off the ground while the brake is off, I don't know if that would be much of a problem. If I set the park brake, I can raise the front end, and it will stay *(at least for the time I allowed it to). That's a bit of a puzzle to me.

If the SCV really is the problem, I will look for one on ebay, craigs, forum classifieds, etc.

If that fails to produce one, there are many suitable SCV's for around $200. that would work, IF they could be physically mounted to the tractor. For a $1650~ savings, I'm willing to do some machine shop fabrication.

Maybe I'll win a lotto, and just go get me a new 3038 :laugh: (note to self... ya gotta actually buy a ticket to have any chance to win). :lolol:

Meanwhile, the old 4100 is a good workhorse. just as it is.
 
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BigJim,

The answer to that question is more than a yes or no. I am not 100% convinced that the SCV is actually the problem, since it is *possible* that an internally leaking boom cylinder seal could hold pressure better one way, (lifting), and not so good the other, (pushing down). The seal on the piston does have a taper to it, which is oriented to seal better when lifting. So I will rebuild the boom cylinders first, to eliminate that.

Since the loader functions perfectly well in all regards except lifting and holding the front wheels off the ground while the brake is off, I don't know if that would be much of a problem. If I set the park brake, I can raise the front end, and it will stay *(at least for the time I allowed it to). That's a bit of a puzzle to me.

If the SCV really is the problem, I will look for one on ebay, craigs, forum classifieds, etc.

If that fails to produce one, there are many suitable SCV's for around $200. that would work, IF they could be physically mounted to the tractor. For a $1650~ savings, I'm willing to do some machine shop fabrication.

Maybe I'll win a lotto, and just go get me a new 3038 :laugh: (note to self... ya gotta actually buy a ticket to have any chance to win). :lolol:

Meanwhile, the old 4100 is a good workhorse. just as it is.


I don't blame u a bit for not buying it for that price. enough to make u sick-huh! why am i still typing in solid black?
:dunno: i would rebuild ur cylinder's and go from their. jeez-now it's back to normal. and i can count on one of my hand's how many lottery tickets i have bought in my lifetime. I bet u thought on the way back home --why did i even come here--why--to loook at all the new tractors:greentractorride: of course:lol:
 
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Discussion Starter · #28 · (Edited)
I don't blame u a bit for not buying it for that price. enough to make u sick-huh! why am i still typing in solid black?[/B]:dunno: i would rebuild ur cylinder's and go from their. jeez-now it's back to normal. and i can count on one of my hand's how many lottery tickets i have bought in my lifetime. I bet u thought on the way back home --why did i even come here--why--to loook at all the new tractors:greentractorride: of course:lol:
:thumbup1gif: lol,,, since I was there already, I figured I should at least sit in the seat of a new 3038, ya know, just to see if I liked it. :laugh:

I didn't even ask the price. :lolol:
 

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I agree that the best course of action if I was in your shoes would be to complete the rebuild of the remaining cylinders. The seal kits are relatively inexpensive, and for a few hours of time invested, it eliminates a huge variable out of the equation and if nothing else should give you piece of mind.

My cylinders never leaked a drop of oil, but the seals had worn to the point of non function.

Additionally, I suggest reviewing the manual for "System Pressure Relief Adjustment" Page 9-25 and 9-26. At fast idle the low end reading deadheading the pressure gauge should be 2347 PSI, high end at 2488 psi.

You seem to be below the low end at 2300 psi, but you were at slightly lower engine rpms. I don't think that it will have any bearing on the issue of holding up the front end, but you have the gauge, the adjustment is easy and it eliminates another variable, again giving you piece of mind. I set mine a needle width below 2500 psi... and called it a day.

With fresh cylinders and full pressure mine felt like a completely different machine. I would get that far before looking into the SCV, chances are pretty good that you may discover irregularities in the boom cylinder seals that solve your problems.

I know you have another leaking bucket cylinder, as an intermediate step, after rebuilding that cylinder, having two known good cylinders in that circuit, can you roll the bucket down and lift the front of the tractor up at all or does it simply extend the boom cylinders?

The SCV although is non serviceable, it can be disassembled, inspected and cleaned with new O-rings installed on the spools (seal only) and the check valves can be also removed, inspected and cleaned. 9-33 through 9-35.

The SCV disassembly would be a last resort. If it is determined that the SCV is unusable, I would pool the forum for the hydraulic experts to see what options of creative plumbing that there are for aftermarket alternatives that could be implemented, and the cost/efficiency of such a system. As well as shopping around for that new old stock SCV kit.
 

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Discussion Starter · #30 ·
Good , Clint. Thank you, that is now exactly my plan. :good2:
 

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Discussion Starter · #32 ·

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I've only used mine once, today but mine held my tires off easily as I was dragging dirt.

How do you put it in float mode?
 

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I've only used mine once, today but mine held my tires off easily as I was dragging dirt.

How do you put it in float mode?
Well not knowing what machine you have I used the 4100 User Manual, though the procedure is universal. You may want to reference your own manual.

Using Optional Hydraulic Selective Control Valve (SCV)
IMPORTANT: Avoid damage! On a model 4100 Narrow tractor the dual SCV is available to operate attachments not having their own valve only. A mid-PTO or loader should never be installed on a model 4100 Narrow tractor.

This tractor model series can be equipped with an optional hydraulic Selective Control Valve (SCV) and hydraulic outlets to operate hydraulically-driven attachments.

MX8993
The tractor-mounted hydraulic outlets are female quick couplers numbered and color coded easy hookup. Decal (A) identifies the couplers: 1 (yellow), 2 (red), 3 (black), and 4 (green).
Attachment hydraulic hoses are also color coded. Match the color coded hose ends to the color coded hydraulic couplers on tractor when making connections.

MX8998
When the attachment hydraulic hoses are connected to couplers 1 (yellow) and 2 (red), move SCV lever (B) left to raise attachment, or right to lower attachment.
When the attachment hydraulic hoses are connected to couplers 3 (black) and 4 (green), move SCV lever (B) forward to dump attachment, or rearward to retract attachment.
Refer to information label (C) if further operating assistance is required.
The SCV is equipped with a float position in order to permit attachments such as blades or loaders to follow ground contours when lowered to operating position. Push SCV lever forward past valve detent to attain float position.
 
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