My Tractor Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter · #1 · (Edited)
I have a '79 JD 410 with two hydro problems. Not sure if they are related or not.

First was slow hydro when the machine got warm. Pressure was down to 1200psi or so after it was warm and sometimes down to 700psi. If lucky the pressure would run at about 2000psi I never really got it higher then that since replacing the pump.

Secondly, and just happened last week. No pressure at the pump. Reverser still works and that is it. No power steering or any other hydro.

So I started cleaning the reverser filter valves. I will be damed if I can figure out how to get the tranny filter pressure relief valve out of the tranny case. I can get the plug out but cannot seem to jimmy the valve it self out. Thought I had before.

The reverser filter relief valves came out clean. I decided to let the machine run for about an hour. The only thing that was warm was the reverser so I decided out it comes. Found a relief valve that was pitted and might of been sticking. New gaskets and valves on the way. Fingers are crossed.

I am also trying to figure out the stroke relief on the pump. I replaced the pump a few years ago. Never have been able to get it up to proper pressure, best was about 2000psi. I got a serialized pump from JD (diagram below). It did not match the original pump as I think the original had the electronic destroke valve and no manual destroke. The diagram of the stroke control valve looks in the old manual I have looks completely different then the ones on the JD site.

I am thinking that the electronic destroke valve is not working. Motor is starting fine without it even hooked up. I am going to order the electronic destroke bypass valve and remove and clean the stroke control valve. I ordered the o-rings and such to do this.

I only assume that I have a serialized pump it is the only pump diagram that has a bolt for the manual destroke versus the t-bar thing.

Question being..... Adjusting the pump pressure yielded no change in the actual pressure even when the pump was new? Could something of been stuck in there since new?

Secondly.... How do I get the bottom part of the stroke control valve out? I barely have enough room to get to the adjustment screw down there, yet alone take the valve out. While I am not at the machine now, I think I have front weights in the way, which might not be standard?

Any thoughts on my procedure?

Thanks,
Geof
 

Attachments

·
Registered
Joined
·
1,346 Posts
For your first question, Anything is possible with new pump. Never saw a defective one, but always possible. More likely, you might have a high pressure leak somewhere that is stealing so much oil, that it can't build pressure.
Second question, usually there is enough room to remove stroke control valve. If weights are in the way, you will need to remove them or remove the pump to get to the valve.
Are you sure the pump shaft is actually turning? Sometimes I have seen the splines strip out of the coupler. Also, are you sure of a good flow of oil from the transmission pump to the main pump? Have you changed filters and cleaned sump screen?
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #3 · (Edited)
For your first question, Anything is possible with new pump. Never saw a defective one, but always possible. More likely, you might have a high pressure leak somewhere that is stealing so much oil, that it can't build pressure.
Second question, usually there is enough room to remove stroke control valve. If weights are in the way, you will need to remove them or remove the pump to get to the valve.
Are you sure the pump shaft is actually turning? Sometimes I have seen the splines strip out of the coupler. Also, are you sure of a good flow of oil from the transmission pump to the main pump? Have you changed filters and cleaned sump screen?

Thanks JD110.

On the stroke control valve. I looked this morning and it is not the weight that is in the way but the front end (or whatever it would be called). I think I can gain a little room if I jack up the the machine and let the left side axle drop down some. I am hopeful on cleaning out the stroke control and replacing the electronic pressure relief with the plug. I never trusted the electronic thing nor was able to get the pressure to actually change with the stroke control. I am not sure it will not change the problem, but at least it will give me piece of mind.

Last time I checked there was a little over 4gpm from the tranny pump.

About 40 hours ago filters and oil were changed. Tranny screen was and sump was cleaned about two years ago.

I am hoping that it is the reverser that valve that was clogged. It does look suspicious to me. I will try both the reverser, stroke control and plug the electronic pressure relief.

If that does not solve the problem, I am thinking about just ripping out the main pressure relief, reverser filter and relief, tranny filter and relief and going through all of them.

Again I am hopeful on the reverser being stuck open as it was the only part that was warm when run for a while.

Any other thoughts?

Good idea on the spline. I will definitely check that the next time I can start the machine.

Thanks again for the help.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #4 ·
JD110,
First, reverser rebuilt no pressure. Spline on pump is spinning.

Got the parts in and the stroke control valve out. Took a pretty good tap from the top to get the stroke control valve to fall out.

Anyways, According to the diagram above part # 43 (thrust washer) and # 42 (o-ring) are suppose to be in the pump, but I cannot find them. Looking down the port from the top it appears to be a straight shot through.

I did get the parts #42 and #43, but have no clue where they belong. The backup ring and the o-ring fit fine (#41 and #40) onto the stroke valve. Just no clue where 43,42 go. They fit snugly around the top of the top flat part of the valve, but I can only see them sliding down into the skinny part of the valve. I put a pic up to help. Also note the dark ring on the top of the original stroke control valve (I did not get a replacement stroke control valve.

Any help would be greatly appreciated.
 

Attachments

·
Registered
Joined
·
1,346 Posts
The area of the dark ring is where the oring should be in the pump body. It is nearly impossible to see it while the pump is in the tractor. If you did not remove the pump I doubt you will be successful changing that oring and thrust ring. The valve is a close tolerance fit in the bore and I don't think it would hurt to reuse that oring. What does the tapered seat on the valve and valve body look like? The seating surface needs to be clean and smooth or the pump will not build any pressure. I would also recheck the sump screen and change the filters again if you haven't already. 40 hours is plenty of time to clog them if there is any contamination in the system. Even a small amount of moisture can cause the screen and filter to clog. They get kind of slimed over.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #6 ·
Thanks JD,
Your advice is worth it's weight in gold.

So the pressure it took to unseat the valve was probably just friction from the o-ring and thrust?

I can now put this back together tomorrow. I am pretty sure I will end up with zero pressure still. At least I will have piece of mind that the stroke control is fine. Plus I spent the $ to get rid of the electronic stroke control relief and put in the test plug. The replacement pump had the manual stroke control so if I ever need it, it is there. Machine starts fine without it. Needs a shot of either when cold, but I heard that is common with this motor.

I read in another post where you helped a fellow out stating that you were not sure if if the stroke control could be dropped back in from the top. I might try because it would be a lot easier to keep clean.

Can the filters being clogged cause 0 pressure?

I am thinking that I will dead-head the pump tomorrow. That way I know which way to go. If the pump builds pressure, I am going to drain the hydro, pull the reverser housing and filter and clean and inspect it. Than again I think I have to pull that filter housing to get to the screen. God what a pain getting that hose off is to get to the screen.

Also going to pull pressure relief valve and body. With all that out of the way I think I should have good access to the tranny filter relief valve and should be able to pull that out.

Is this a good plan or should I be looking at other valves and pressure reliefs? As far as finding leaks at the loader valves or backhoe valves I am at a loss.

Or should I just be dead-heading the backhoe and the loader before I start tearing everything apart?

I will at least change the filters when I drop the oil. Cheap insurance.

I see you have 30 years on these machines meaning you saw the straight 410.... or 4100... I have to hand it to you fellows for working on such a machine. I have heard time and time again that the Case 580 is a lot better homeowner machine due to being able to fix the hydro when it comes to issues like this.

Are the new machines easier to diagnose?

I want to mention this much. I have a stabilizer piston that is leaking bad. I will fix it soon ($180 for the repair kit is the issue) but this would not be any part of the issue I am having of current?

Thank again for all the help.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #7 ·
Opps I forgot.

The needle part of the valve??? looks fine. I am not sure 100% as where it seats into the valve body looks a little weird. Not chipped or nicked just not like you would think when new. I am 80% sure it is seating well.

At $63 for the valve I will see what dead-heading the pump leaves me.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #8 ·
Went to dead head the pump today. Could not find the JIC plugs to do such. So I tore apart the pressure relief, Hydro filter and associated valves, tranny filter, tranny pressure relief valve, and tranny screen. Tranny screen was a mess. Cleaned all and replaced o-rings as needed as well as replaced both filters. Fired her up and still no pressure. LEt her run for a while and still could not find anyplace getting warm.

On a whim, I dropped the valve next to the stroke control valve. Found metal in the bottom cap under the valve. Enough to fill a thimble almost 1/4 way. Cleaned that all up and still no pressure.

Seeing the metal I am worried that when I dead-head the pump tomorrow I will see that the pump is bad.

Is the pump toast or can I rebuild it?
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #9 ·
Well today I was able to cap off the pump. Got a cap onto the pressure line running back to the pressure relief valve and a cap on the steering line. No pressure at the pump.

Any thoughts as to what Io should do next?
 

·
Registered
Joined
·
853 Posts
Well today I was able to cap off the pump. Got a cap onto the pressure line running back to the pressure relief valve and a cap on the steering line. No pressure at the pump.

Any thoughts as to what Io should do next?

You've got me a little confused with some of the comments you've made along the way. Firstly, the non-serial and serial pumps are of similar design. Serial pump has metric threads and a tin serial plate on it which makes it pretty easy to ID. As to the manual shut-off with a hex-head bolt? That's one I've never seen, but I haven't worked for Deere since 1991. I've added manual shut-offs to all three piston pumps Deere used . . . little German pump with key-way shaft drive (.68 or 1.3 cubic inches per rev), USA 2.4 and 3 cubic inch pump with splined drive, and 2.4 and 3 cubic inch metric serial pump also with splined drive (maybe some 4 cube pumps also). All used T-handle manual shut-offs if added. Later USA and Metric pumps also came ported for electric destrokers, usually used for machines that get parked where no electricity is available for block heaters and very cold temps. The metric pumps DID use a hex-head bolt for the stroke-control adjuster, unlike the non-serial pump that used an Allen head or a flat screwdriver slot head.

The Deere piston pump cannot draw oil to itself. It MUST be fed oil by the transmission pump. So, all main pump tests are useless until you verify you are getting feed oil to the pump. If in doubt, stick a 5 gallon bucket under the feel line when unhooked. Start the engine and see how fast that bucket fills.

If you verify the main front pump IS getting proper oil (at least 5 GPM per minute), then proceed to find out what's wrong with the pump. Main wear item is the stroke-control valve at the tapered seat. If that is not the problem, pull the pump out and fix it. Not very complicated and if there IS a problem inside, it will be clear to see. Eight pistons and springs, eight inlet valve, eight outlet valves, and that's about it.

Deere tractors often develop oil starvation problems to the front pump when the main pickup screen inside the transmission case plugs - and stops the feed/transmission pump from sending proper oil up front.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #11 ·
JDE,
Thanks for the reply. Original pump had electronic destroke. The pump in the machine is a replacement pump. The fact that it is green is a dead give away. It has a serial plate. The replacement pump had a regular bolt for the shut-off as shown in part number 15 of the diagram in my first post.

To test the tranny pump where do I open up the line at? I would think where the feed line to the pump where it the two lines are coupled with a piece of rubber hose? The line from the reverser to the pump? If so I will give this a try tomorrow and report back.

I just took apart the stroke control valve and cleaned and repacked it. All looked fine.

What are your thoughts on the metal that I found on the other side of the stroke control valve?

The machine is stuck with the loader and stabilizers down and the backhoe in a trench. I sure hope it is not the tranny pump as the machine cannot be split where it is.

Are their actually parts in the pump that could break?

Thanks again for all the help.
 

·
Registered
Joined
·
853 Posts
JDE,
Thanks for the reply. Original pump had electronic destroke. The pump in the machine is a replacement pump. The fact that it is green is a dead give away.

New replacement pumps from Deere, serial or non-serial have always been green, or orange-green. Serial pump is easy to notice since it has a serial tag and metric fittings.

As to that bolt your's has? Must be a running change they made which seems kind of dumb to me. I attached a Deere image showing the T-handle on the metric pump (how it used to be). The idea of the manual shut-off is that you can turn it off and on, by hand - thus the need for the "T" handle. But . . . many older pumps did not come ported for an electric destroker, whereas all the metric pumps did. So, maybe Deere figured if you needed to use the destroke often, use the electric and not the manual? Who knows. It's still dumb and if it was mine, I'd weld a T-bar onto it.

Those machines don't need any destroker if everything is perfect. But, on a used machine, things will never be perfect. So, you get small internal hydraulic leaks that force the hydraulic pump to make pressure oil while cranking. This burns up starter motors left and right. Thus the need for a destroker in most. It also why jiggling the steering-wheel why cranking somethings improves cranking speed.

You ask if anything can wear or break in the pump? Heck yes. We had the most hydraulic problems with wheeled loader/backhoes. Crawlers don't use piston pumps or common sumps and held up better.

Remember that your machine has a common hydraulic sump in the transmission case. So, any part that wears or fails anywhere winds up in the hydraulic oil. The only protection to prevent that debris from being sucked up by the transmission pump is that long round filter I told you to check. If a machine fails, e.g., transmission tooth, brake linkings, bearing wear, etc., it all winds up in the hydraulic oil.

You say you found metal in the main pump. That could be from that pump itself, or from anywhere else on the machine including transmission, hydraulic cylinders, etc. The biggest problem we had with backhoes - once there was a failure - is getting them cleaned out which is near impossible to do completely.

The transmission pump (a simple gear pump) feeds the reverser and the main front pump. If the reverser is still working 100% OK, that you know the trans pump is still working to some degree. If a trans pump is worn, it will get worse as the macine heats up, but ought to work to some degree when you first start it. 410 probably has something like a 7 gallon-per-mintute trans pump. Main pump up front needs at least a couple of gallons per minute to work well WHEN you are using hydraulic functions. But, when not - at first start and hardly using anything - it requires very little oil. Just has to be kept wet. That is why the main pump has the extra test-port. That port taps into the feed-oil from the trans pump. ANY pressure indicates the main pump has feed oil available, and ZERO means it is starving.

Considering the reverser still works well, I'll assume you don't have a general wear problem. More of something broken.

Again, you have to verify oil is getting to the main pump. Does not matter is it's 1 PSI or 20 PSI. Just must be oil present for that front pump to operate. Obviously, if it DID only have 1 PSI, it would probably quickly drop to zero as soon as you used a function, since such low pressure would indicate little feed oil available.

Transmission pump cannot be repaired; just replaced. It's a simple gear pump with no small parts.

Main front pump has many parts. Big shaft on two adjustable cone bearings. 8 Lifters/pistons riding on a roller-bearing off-set journal, eight inlet valves, and eight outlet valves. Also a small filter inside the stroke-control housing.
Main pumps can be repaired, but the pistons ride directly in bores in the main housing. If they get scored, the pump loses capacity, which may or may not matter to you. If it's a 4 gallon-per-minute pump that has gotten scored -it many only pump 3 GPM once you fix it -which is still a lot of oil and you may never notice the difference.

Often, brake linings are the big problem in wheeled backhoes. The come apart and get into the hydraulic oil, but the brakes are so powerful they still work fine even when the linings are gone and all is now metal-against-metal.
Subsequenlty, the oil and both pumps get metal filings running through them that ruins both over time.
 

Attachments

·
Registered
Joined
·
56 Posts
Discussion Starter · #13 ·
JDE,
Thanks for the detail. It will really help me out. I was just about to go outside and test the tranny pump.

I previously took the entire passenger side hydraulic system apart and cleaned and replaced whatever needed to be repleaced, (reverser filter and relief, tranny filter and relief, reverser itself, main pressure relief, and tranny screen). Tranny screen had a lot of sludge on it (non metallic).

This machine had the electronic destroke. Never really needed it. In the process here I got the plug to replace it.

The metal in the pressure pump was more like flakes. About a quarter the size of your small fingernail. Is it possible for something like that to travel up to the pump or is it more likely from the pump it self?

Seeing that the reverser works well does that show that the tranny pump is at least pumping something? On the up side, after rebuilding the reverser I can now feel the indents in the reverser control handle. Something that was missing before.
 

·
Registered
Joined
·
1,346 Posts
Actually the metal you are seeing is probably from the pump itself. Oil from the transmission is filtered through the main filter in transmission housing before it gets to the pump. So, unless someone ran the machine with filter missing, no "flakes" should get through the filter. As jdemaris mentions, frequently brakes cause contamination but usually that is very fine metal filings and some of that is so fine it can get through the filter. It doesn't sound like that is what you have. I am going to guess you will find that the pistons in the pump have seized. If so, then the pump is trashed and will need to be replaced. Let us know what you find out.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #15 ·
JD110,
Thanks for the advise. As far as I know the machine was never run without the filters.

Today I tested the tranny pump. Best I can figure I got about 4 to 4.5 gpm. Out comes the hydro pump tomorrow. :)
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #16 ·
jd110,

Well finally got around to getting the pump out. The pump spins pretty easy by hand. Right now all I have done is take the stroke control unit off the pump as well as taken apart the two valves within the stroke control portion. Found a little more metal flakes (about as much to cover half your small fingernail.

I can still spin the pump by hand freely and cannot feel any roughness. I cannot see anything moving looking at the pump from the stroke control side.

Should I pull it apart more or is this what a pump that has all the pistons seized would do?

Thanks again in advance.
 

·
Registered
Joined
·
853 Posts
jd110,

Well finally got around to getting the pump out. The pump spins pretty easy by hand.
Should I pull it apart more or is this what a pump that has all the pistons seized would do?

Thanks again in advance.
There are eight big caps on the outside of the pump. Each cap holds a piston and spring in. Pull each cap off, and pull each piston and spring out. That's how you're going to see condition of the pump. Each piston rides in a cylinder bored directly in the pump body. Usually, you just stick your finger in the end of each piston and pull it out.

Basically, as far as moving parts go - the main shaft (that rotates) has an offeset crankpin on it - just like a single-cylinder gas engine would have. That crank-pin has a roller bearing on it. All the pistons ride directly on that roller bearing surface. So, as the shaft turns, the pistons all go up and down. The other moving parts are self-actuated. Eight inlet valves and eight discharge valves. All basically just one-way hydraulic check-valves that open and close with flow.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #18 ·
Jdemaris,

Thanks for the help. I did as you instructed. Got 3 caps off. I cannot get the pistons out of the life of me. It took a pretty hard hit with a brass drift to get them back down. Turn the crank and they jam up at top again. Takes a pretty hard tap again to get them to go down.

Took the fourth cap off. Half of the inner spring is gone / hole in the piston.

I wish the pump was repairable by me, but I am sure it is not. Short of buying one is there a way to have someone rebuild it? I found a guy down South that has them rebuilt for $785 + $300 for core. Funds are tight here and just trying to get out on the cheap with this machine!

The current pump was rebuilt by "John Deere" in May 2003...... :(
 

·
Registered
Joined
·
853 Posts
Jdemaris,

Thanks for the help. I did as you instructed. Got 3 caps off. I cannot get the pistons out of the life of me. (
Sounds like you've really got a mess. A pump that bad is unusual, but I've seen a few. A far as I know, there IS no true way to "rebuild" the pumps. They get patched up and resealed. Unlike a gas or diesel engine, the cyinders in this 8 piston-pumps have no replaceable sleeves and no over-size pistons available. At the Deere dealership, they got thrown together as-is, or got chucked on the scrap pile. One disclaimer though. Since over the years these pumps have gotten SO expensive, maybe somebody somewhere is actually boring them out and sleeving the cylinder holes. I've kind of lost track. I haven't worked as a Deere mechanic since 1991.

I know you mentioned a price for a "rebuilt" pump. If you're even considering it, ask what that word "rebuild" means to the person sellling it. That word is abused and misused by many. Same goes with fuel-injection pumps, but that's a different subject.

About your pump. If you get the pistons out, and . . . and by some miracle just find mild scoring inside the pump - you can hone it a bit and put in new pistons and springs. It might only work at 75% capacity, but you'll never notice the difference. All depends on how scored it is.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #20 ·
Jde,

Thanks again. I just spent a while on the internet. I might go with the guy with the $785 pump. Seems like a nice outfit. I will call and get the warm fuzzy. I would rather deal with someone that is actually "rebuilding" them.

I bought this machine with the new JD Reman pump as I thought it would be worth it. After all it was a John Deere rebuilt................ Worth about nothing to me now and I only put about 300 hours on the machine and I am guessing 40 hours on the pump itself. I am really disappointed in the JD reman pump. I really tried to keep the machine as clean as possible hydraulic wise.

After seeing the pistons are $51 each at JD.... that was enough for me to suck it up and buy a whole new reman unit.
 
1 - 20 of 29 Posts
Top