I’m having a problem with an 1995, EX400LC-3. The pump was going into minimum pumping mode after the machine was run for 10-15 minutes. Then after sitting for ½ hour the machine would run fine for 5-10 minutes then go into minimum mode again. Now the machine is in minimum mode all the time even after sitting all night. All functions (Travel, swing, boom, dipper, bucket) of the machine seem to work fine, but very slowly. It tracks straight also. One other thing I also noticed is the auto idle does not work now either. The machine will stay running at an increased speed all the time even when the controls are left in the neutral position or the pilot shut off valve is in the locked position. If you select General, Ditching or Precision modes that seems to have no effect on the speed at which the boom moves either. Any ideas? Thanks.
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EX400LC-3 Hydraulic problem
- Thread starter Scrapper
- Start date
John C.
Senior Member
Your machine has a controller either behind the cab or over in the battery compartment on the right front of the house. There are two diodes which will tell you what the computer is doing. Let us know what is going on there.
You can also disconnect the solenoid on the pump and it should go to full output when something is operated. The machine will still work but it will pull the engine RPMs down. If the pump does not go to full stroke then there is a pump problem and it will most likely need to be torn down for repair.
Also have you checked the oil in the bell housing. It was common for the rear main on the engine to leak and fill that compartment full. The oil acts as a fluid brake and will actually get hot enough to burn the paint off the bell housing.
Let us know what you find.
You can also disconnect the solenoid on the pump and it should go to full output when something is operated. The machine will still work but it will pull the engine RPMs down. If the pump does not go to full stroke then there is a pump problem and it will most likely need to be torn down for repair.
Also have you checked the oil in the bell housing. It was common for the rear main on the engine to leak and fill that compartment full. The oil acts as a fluid brake and will actually get hot enough to burn the paint off the bell housing.
Let us know what you find.
cutting edge
Senior Member
Does it have wiring for hydraulic counterweight removal?
a short in this harness often causes slow hydraulics on the deere 450 clc's
a short in this harness often causes slow hydraulics on the deere 450 clc's
machine
Well-Known Member
The 2 controllers are under cover that looks like a tray behind the seat. The PVC is the larger unit on the bottom. the top unit is the throttle or EC. They each have a red LEC (light emitting diode) . They both should have a slow steady pulse. You will find if you cover one while observing the other they are easier to read. However first check the fuses. Looking over the seat on the left row starting closest to you they should be 1A 1A 5A 1A 1A 5A 1A 5A 5A 10A Make sure the 1A fuses are correct. They protect the controllers,a 1.5A < and they will toast the controllers in the event of an electrical fopaw. I have found that on older machines the insulation on the wires breaks down especially under the hydraulic tank. After verifying the fuses remove the cover and look at the red LEDs if they flash you at least have power. No flash, remove
them and open them, if they smell burnt it would be a good idea to replace the harnesses or you may burn the new units regardless of the correct fuses.
If all looks ok and all wires are connected start engine. Now go to the main control valve and find 2 DP sensors with 3 wire connectors. Disconnect 1 and you should here 1 pump go into stroke reconnect it, the pump goes out of stroke. Repeat with the other DP sensor.
them and open them, if they smell burnt it would be a good idea to replace the harnesses or you may burn the new units regardless of the correct fuses.
If all looks ok and all wires are connected start engine. Now go to the main control valve and find 2 DP sensors with 3 wire connectors. Disconnect 1 and you should here 1 pump go into stroke reconnect it, the pump goes out of stroke. Repeat with the other DP sensor.
machine
Well-Known Member
Cutting Edge is right. Even with out the C/W device the harness is there and a problem in it will de-stroke one pump. If the wires on the pump solenoids can move or are dangling the wires at the solenoids can break inside the insulation.
Check them with an ohm meter. If they check out then check to see if one wire for each solenoid has 24v. The other wire is the ground which is done by the PVC.
Check them with an ohm meter. If they check out then check to see if one wire for each solenoid has 24v. The other wire is the ground which is done by the PVC.
John C.
Senior Member
Hey guys, this is a Dash "3" and not a dash five. There is only one computer that has two diodes on the face of the box. I've never seen a Dash 3 with a counterweight loader but that doesn't mean there can't be one.
Sorry for not getting back sooner, I was out of town for the weekend. The main wiring harness for the machine was replaced a few years back. The machine hasn't been run but maybe 600 hrs since then so the harness is still in great shape. The machine currently has about 16,000 hrs on it and had just over 15,000 when I purchased it in 2002. I had a problem with the engine not speeding up when you pushed any of the buttons to select the power setting. The harness was very brittle and missing insulation in spots around the pump and engine. The mechanic that looked at the problem suspected that a short in the harness caused the EC to burn up since someone had replaced some of the fuses with larger fuses at one point in time. Long story short, new harness, EC and correct fuses and the machine ran like it should. I pulled my aftermarket AC unit lose which sits behind the seat and on top of the EC and PVC (there are two boxes) so I could see the diodes. The box on the top which according to my service manual is the EC and it blinks 5 times then pauses and then blinks another 5 and keeps doing this. The PVC which is supposed to be the lower box does not blink at all. I unhooked the solenoids (sensors on the regulator block) to see if that made any difference in how the machine (pump) ran and it did not. I used a volt meter to check for voltage at these solenoids and have non (0v). Both solenoids ohms out at 13.6. I have used a test light and a volt meter to check all the fuses behind the seat and they are all good (24v). I do not have the hydraulic counterweight removal but even if the wiring is there like I said the main harness was replaced a few years ago and is in good condition so I don't suspect that is my problem. Plus both sides of my pump is basically dead not just one side. If I had to make an uneducated guess, I would suspect the PCV is the problem but don't want to spend the money ($1600.00) on a new one if it is not. I guess having a spare one on the shelve would not be a bad idea for situations like, but could do without. Any suggestions?
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I took each of the 1 Amp fuses out and checked them with a ohms meter and they were all good. After re-seating the fuses I now have a blinking light on both the PCV and the EC controller. Could it be that I had a bad connection on one of the fuses? The machine seems to be operating properly now. I'm now going to run it for a while and see if the thing will quit after a 30 minutes like it did before. I sure hope it doesn't.
machine
Well-Known Member
It is possible to have bad connections, also check under fuse box for corroded
joints and wire terminals. Make absolutely positive that water from the A/C can not drip onto control units. Cover them with something that will shed water.
OK, I just run the machine for about 15 minutes and it blew one of the 1 Amp fuses. The fuse that blew is the one that is removed in the picture (forth one over from the left on the bottom row or closest row to the seat). Does this pretty much single out the controller or could it be something else? I have one solenoid on one of the regulator blocks that the insulation is cracked on both wires near where the wires go into the solenoid, but I have that taped up pretty good and I don't think the wires are able to touch. It has been like that for some time. But who knows maybe it has gotten to the point where it is shorting out inside. If I replaced the fuse and run the machine with that solenoid unhooked would it tell me if the solenoid is possibly shorting out if the fuse doesn't blow again? Or would a Dr EX tell you if one of the solenoids shorted out from a stored code?
machine
Well-Known Member
From the picture the bottom row if it box were installed looks like the left side row with 2 1A fuses closest to you. after them they should read 5A then 2 more 1A fuses then a 5A then a 1A that had failed. Then the next 3 fuses should be 10A. The fuses in the picture do not appear to be in the correct order.
The fuse that is missing in the picture is for the monitor controller that is beside the 2 computers behind the seat. I am reading out of the Hit. troubleshooting book. IF there is a faulty sensor causing the 1A fuses to fail disconnect all the 5 volt sensors. Than run the machine with 2 sensors connected I would start with the DP sensors in the control
valve. If they survive the test of time connect the 2 angle sensors.
The fuse that is missing in the picture is for the monitor controller that is beside the 2 computers behind the seat. I am reading out of the Hit. troubleshooting book. IF there is a faulty sensor causing the 1A fuses to fail disconnect all the 5 volt sensors. Than run the machine with 2 sensors connected I would start with the DP sensors in the control
valve. If they survive the test of time connect the 2 angle sensors.
machine
Well-Known Member
And after time if the fuses haven't not failed connect the 2 pressure sensors. There is one other 5v sensor in the throttle to keep in mind. Verify your suspicions until you are completely convinced you have the proper sensor before you buy new. I am not sure but
I don't see why the #7 fuse failing would cause the main controllers to stop operating.
I don't see why the #7 fuse failing would cause the main controllers to stop operating.
machine
Well-Known Member
I have a conflict between the book and the wire diagram. according to the book #7 fuse is protecting the PVC. The schematic has it going to the monitor controller.
hahaha..
JackDeere
Active Member
Hey Scrapper, You might check the speed sensor. It can effect both pumps. Typically the speed sensor on the -3 will get debris on it from the starter. Sometimes if you clean it off and reinstall it will do the trick, if it is not damaged.
Thought I might as well give an update as to what caused the problem with the PVC fuse blowing.
It turned out that when the A-sensor heated up it would short out and cause the fuse to blow.
I had the local dealer come and scan the machine with their Dr. EX. We replaced the fuse and ran the machine when it was cold and he noticed that one of the A-sensors was installed 180 degrees off. About a month prior to this problem I had the hydraulic pump completely rebuilt and apparently even though I was told that the pump was run on a test stand and checked out OK, what they didn't tell me was that they had no way to run the electronics associated with this pump. That explained my sudden increase in fuel consumption and the black smoke coming from the exhaust after the pump was replaced. I just thought it was from the extra power the pump was taking to run being newly rebuilt and not having any bypass on the pistons.
The local mechanic correctly set the A-sensor and then we ran the machine again. After about 15 minutes the fuse for the PVC blew and then he unhooked both A-sensors and found out that the same A-sensor that was installed 180 degrees off was the one causing the PVC fuse to blow. He replace that A-sensor and we ran the machine again. The fuse never blew again but the Dr. EX was still showing an "open" to the other A-sensor which the dealer did not have in stock. After ordering an A-sensor and a return service call ($) to install it, the machine was running well until my recent alternator problem.
It turned out that when the A-sensor heated up it would short out and cause the fuse to blow.
I had the local dealer come and scan the machine with their Dr. EX. We replaced the fuse and ran the machine when it was cold and he noticed that one of the A-sensors was installed 180 degrees off. About a month prior to this problem I had the hydraulic pump completely rebuilt and apparently even though I was told that the pump was run on a test stand and checked out OK, what they didn't tell me was that they had no way to run the electronics associated with this pump. That explained my sudden increase in fuel consumption and the black smoke coming from the exhaust after the pump was replaced. I just thought it was from the extra power the pump was taking to run being newly rebuilt and not having any bypass on the pistons.
The local mechanic correctly set the A-sensor and then we ran the machine again. After about 15 minutes the fuse for the PVC blew and then he unhooked both A-sensors and found out that the same A-sensor that was installed 180 degrees off was the one causing the PVC fuse to blow. He replace that A-sensor and we ran the machine again. The fuse never blew again but the Dr. EX was still showing an "open" to the other A-sensor which the dealer did not have in stock. After ordering an A-sensor and a return service call ($) to install it, the machine was running well until my recent alternator problem.