Go Bottom4000 series hydraulics
 | Jeff H.
Join Date: Posts: 1 
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2000-10-21 20738
I am trying to figure a hydraulic problem out on my 4600. It is a 2000 model and has about 30 hours on it. I have a 460 loader that I am using. Problem: When I go to grab a bucket of dirt, tilt back, then drive to pour it out (stopped), the bucket goes down to pour the dirt out but then stops, hesitates for about 2 to 3 seconds and then at a high speed goes the rest of the way and rams itself into the end of the cylinder ends. I don't know if there is still air in the system that can't get out some how? I have tried higher rpms and lower rpms and nothing has worked yet. Have talked to the dealer about it which they are looking the problem up. Any comments would be appreciated... ThanksAlso for those of you that run the 4000 series compacts, be careful of the flat head screw that holds metal plate to the forward foot pedal for the cruise control. The plate is for the electro-magnet to hold the pedal in place. Anyway, that flat head screw is pulled down tight but sticks out just enough to catch the housing of the electro-magnet when you let off from full speed and causes the pedal to stick on and you are fearing the destruction of the expensive green paint on the front let alone the other obstruction you have in your way. Just a note to let you guys be aware and maybe check it out on your machines.
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| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley 
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2000-10-22 20742
Tractor hydraulics are open systems, not like brakes on a car. Ordinarily, any air goes through the system and bubbles out of the oil in the reservoir. Sometimes hydraulic cylinders are cycled to clear any air in the cylinders. Cycling is done by moving a cylinder one way to its end position and holding a few seconds, and then reversing. The relief valve should be heard while holding at the ends. What you're describing seems somewhat normal, but the high roll forward speed and crashing into the cylinder ends may be extreme. A bucket with a load doesn't need hydraulic pressure during much of its dump. The weight of the load will rapidly expel oil out the return side of the cylinders back to the reservoir. After the load is dumped, there is little weight, and the bucket won't roll further forward on it's own without hydraulic pressure. I believe it can take the pump a few seconds to 'catch up,’ at least mine works a bit like that. A restriction in the dump pressure side of the circuit could produce what you describe. ....
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| Jeff H.
Join Date: Posts: 1
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2000-10-22 20756
I understand the theory of weight not needing any help from the system, but maybe this is common in all the 4000 series. I have not seen this with my dad's case skidloader in all the numerous hours I've spent in it. Resriction, could be too, but why would it go slower when dumping and then when the bucket is empty it waits 2 or 3 seconds then takes off at full speed. I thought this might just be the weight causing a reaction like this so I tried it empty, and it still does it. It doesn't really bother all that much other than the fact that this tractor has 30 hours on it and my dad's skidloader has how many hours on it. His other tractor with a loader does not do it either. So I was raising the question to you guys out there to see if it is common with the little deeres or if I need to be seeing my dealer about it so it can be turned in under warranty. I just don't to ignore it and then something breaks or snaps after the warranty is up and then my green in my wallet will be paying for it. Thanks for the reply! ....
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| Brent B
Join Date: Posts: 1
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2000-10-22 20773
I have also noticed the delay when dumping an empty bucket, and have chalked it up to air in the cylinder, but have not tried to bleed it yet. There are also those extension lines along the left
push arm which are dead-ended and might hold some air. My 420 loader has a dump circuit regeneration circuit, which means when the control lever is pushed all the way to the right the rod end oil is fed back into the head end along with the pump flow. This speeds up the dump cycle. Could this be why it is
speeding up on you? ....
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 | harvey
Join Date: Sep 2000 Posts: 1550 Moravia, NY 
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2000-10-23 20781
Your dump or curl forward has a two position valve. If you move your SCV lever a little to the right it will dump slowly. If you move it all the way the the right it will dump fast. The hesitation you are noticing is in between the two. One of the operator manuals for tractor or the bucket shows it, I do not remember which. Of course I did not read the manual either but went looking after experiencing the same stuff. Yes and I asked the mechanic he knew it. The JD dealer in Cortland, NY has some sharp people there. ....
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| Kenny
Join Date: Mar 2004 Posts: 46 sale creek
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2000-10-23 20822
Jeff, the regenerative circuit that Brent mentioned is supposed to prevent the delay tou are experiencing. It could be that the regenerative circuit is blocked out. There is an adjustable stop in the linkage which may be in the wrong position for loader operation. The stop needs to be in position if the scv is to be used for nonloader work. Ask your dealer about this. ....
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