JD 4400 hydro problems I need your input please.

[Hillbilly]

Guys,
My tractor developed a serious problem this past Tuesday and it is currently back in the shop and the dealer cannot get it to duplicate the problem[hmmm].I need your input if you have experinced a similar problem because my dealer has no clue to what might be wrong since the problem will not duplicate itself for them.Any information you supply me I might be able to help the dealer trouble shoot this problem.
Heres the story:
About a week prior to May 30 I carried a rock up a steep incline in my bucket and was amazed at how well my tractor performed the task.I got to the main road and started travelling towards the house and I noticed something happen which felt like a lost of resistance in the Hydro-pedal and a momentary drop in speed and then the tractor started performing normally again.
Tuesday May 30: I am using the 4 in 1 loader to grapple a couple of logs and I back away and stop for a second and in the meantime I set the backblade on the ground and I get ready to raise the blade and the hydraulics will not pick it up,and at the same time I try to raise my 4 in 1 off the ground and it will not move,I try to curl the bucket and lift the front end of the tractor of the ground and no luck,well I wait a couple of minutes and everything starts functioning properly.Now I decide to go to the woods and do a little work.I start out the road on a small incline and I notice the tractor does not go up the very small incline/raised place in the road very well(just a momentary thing).
Well down in the woods I go and I pick up about a 500 lb rock and start up the hill and the tractor keeps going slower and slower and I have the engine running at 2600 rpms.I let off the hydro pedal to try and nurse this sick tractor out of the woods,I finally get it up on the road and it will not hardly crawl on the flats,the same time I notice the hydraulics are sounding funny and my engine temperature is running hotter than normal and I can feel the heat going up my pants legs, coming off the rear end .I put the tractor in 2nd and try 3rd gear and it seems to do okay on the main road,well I drive to the house about an 1/8 th of a mile and I shut the tractor off and you cannot even hold your hand on the rear end it is so hot,I decide I need to clean this thing up because it is going back to the shop and I spray a little water on it and the steam rolls off of the rear end.The bullseye on the gearbox was full and I could actually detect a scent of hydraulic oil because this thing was so hot and not a leak to be seen anywhere.
The dealer cannot get the thing to duplicate the problem,my warranty epires June 28 of this year.

<font color=red>CAN ANYONE HELP ME ?I NEED TO GIVE THE DEALER SOME IDEA OF WHAT COULD BE WRONG.</font color=red>

Thanks
Hillbilly

 

[TerryinMD]

Hillbilly,

Let's do some basic "just the facts, sir".

1. How long were you operating the tractor?
2. What were the exact sequence of events to lead up to incident?
3. How about topology just prior to the incident?
4. What is the dealer doing to try to reproduce the incident?
5. Is the tractor leaning to one side or the other prior to this happening?

Sounds like a combination of inclines/slopes and what you are carrying to me which triggers the problem to me. I would have the dealer haul the tractor back to your site and do exactly what your are doing to reproduce the problem.

I wish I could provide some other insight but this is all I can think of to help.

Terry

 

[Hillbilly]

Thanks Terry.

 

[Anonymous Poster]

<font color=blue>…up a steep incline…and start up the hill…on a small incline…</font color=blue>

Is it possible, you have “FOD” foreign object debris (…military was foreign object damage) inside the “rear-end” body that is floating around within the hydraulic fluid… and when going up some incline… this debris (being large enough) plugs up a internal “suction” port or severely restricts the port causing this overheating/cavitation/starvation of hydraulic fluid… then when you are back on level ground… the amount of suction will keep this “debris” at this port until it randomly breaks from this suction…and starts floating around again…?

 

[gewpe]

I'm a new forum member. Just got a used 4400 a couple of months ago and have been learning rapidly.

I had a similar problem. Soon after I got the tractor, I experienced a clogged rockshaft filter that is described on the forum. During the process of correcting that I noticed that the hydraulic oil in my tractor was overfull. The dealer said that would not harm anything. Because I have learned to never overfill engines and such, I drained it do to the recommended level (at the bulls eye). Might have been as much as a gallon of extra fluid. Afterwards as I went up a long hill I started to loss power as you describe. It stopped when I got to level ground. I continued and on another longer uphill stretch the same thing happened but I wasn't at the top of the hill so it stopped completely. I was able to turn around and back the rest of the way up the hill.

The fluid level may have been a little low as I am just now learning to lower the fel and to check the level. I added more hydraulic oil and have not had any more problems.

So maybe you should have the dealer operate the tractor up an extended slope and see what happens.

 

[Anonymous Poster]

I have the same problem on my 4700 HST. There is a safety switch under the seat which can cause the engine to loose power if it senses that the operator is not in the seat. This only occurs when the pedals are being depressed. It always happens on a slope and never on level ground.

Tony,

 

[Hillbilly]

This is not a problem with a safety switch.I know how the tractor acts when the safety switch is not making contact.

 

[Hillbilly]

Did your hydro get hot like I described mine doing?Where is the rockshaft filter? There is a wire mesh filter that I have had out underneath my tractor at one time.My tractor is approaching the 500 mark which the service manual calls for the hydro oil/filter to be changed.
I am going call the dealer tommorow and recommend they drain the hydro and install new filters etc and see how the oil looks,if there is a lot of debris etc,and if they cannot get it to duplicate the problem have him bring it home to me and let me try it again.

Best regards
Hillbilly

 

[gewpe]

Hillbilly,

The rockshaft filter is a small mesh filter located in one of the connections to the rockshaft control valve. It’s under the seat and a pain to get too. Apparently JD has had some problems with it. If it gets clogged it becomes dislodged and can cause problems with your 3 pint hitch. I found parts of my filter in the rockshaft control valve. There is a good thread on the forum. Search for rockshaft filter. I don’t think it’s related to your problem, I mentioned it because that’s how I noticed my hydraulic fluid was overfull.

I did not notice my fluid getting hot. I parked it as soon as I could, but I expect that it was. My problem was corrected just by added more fluid.

Good luck.

 

[Tags]

Hillbilly,
Not fer nothin',but could it have been low on fluid??I think even if it was a little low that would make a big difference,especially since the everthing on the machine is driven hydraulically,you need a certain amount of oil to keep the proper operating temp,and if was a little low and you were climbing slopes it may have been starving for fluid and heated the fluid in there over operating temp.I would check with the dealer and see if 1 the oil was at the correct level 2 if the oil smells burnt,if none of these are a factor see if the dealer will send a mechanic out to your site while you run the heck outta the thing and see if it happens again.Hope this helps,cause it sucks to have a problem and not be able to pinpoint it.