We have a new 2023 DX140 that absolutely will not grade. The boom cylinders act like they are full of air. When you raise or lower the boom the entire arm and stick bounce. I saw some posts of a similar problem with one in the UK. Anyone havin g the same issue here? Thanks
Good day Yes you are correct spent many hours on that issue for volvo. Kind regards Uffex
Thanks for the reply. Can it be fixed or should we trade it for a Kobelco or Cat?
Good day Ponch You can make improvements, however my experience was that often the operator was not so satisfied. You have two hydraulic pumps which each power one side of the main valve chest, both sides of the MCV has a boom & arm valve, it means that the pump flow will join and choose the easy way, not the operator. That is Ok for bulk excavation but not for fine work, unless you are determined to stay with the product it may be easier to buy a machine with a load sensing system such as Hitachi, it was a firm favourite for fine control when I was messing with the issue. The best result I had was to connect the arm negative cylinder side to the boom raise. By selection when you pulled the arm in it automatically raised the boom. If you need more information, I have plenty on file. If you go down the replacement route, I suggest you rent one first and try before you buy. Kind regards Uffex
ponch458. Did you just purchase or rent the machine from a dealer? Whats the story for this unit?
By saying trade, I assume you own it. I would guess you still have warranty. I would make Doosan fix it. That trade value will leave a nasty mark in your checkbook.
We have owned it for several months. It is a very well built machine with some great features. It does function well under load like excavating and moving material. I’m not sure what Doosan was thinking when they set this machine up in such a fashion. We don’t do mass excavation with a max hi ne tii hi is small. We think it should be more useful for finishing.
We do have a great dealer. Unfortunately, I don’t think his service people have a lot of experience. Seems to me I should be talking directly with Doosan’s engineers
Wow. You know a lot about hydraulic functions. Thanks so much for your reply. I am going to pass this in on to our dealer. Hopefully, he will get with Doosan.
I guess I should explain our situation a bit. We live in a very small town in Alaska where there is no road connection to the outside world. We get our freight via barge or aircraft. We hardly ever get to try out a machine before we buy it. So far we have been pretty lucky. Most of the time folks we deal with are very honest.
You may end up talking with a Doosan engineer. Your location makes all of this that much more difficult. It would be interesting to see if another '23, 140 handles the same way. If your dealer has another 140 you could run, spend some time in it and see if it's your machine or if they all run that way. That is probably the first thing to do. If they all run that way, I would guess this wouldn't be the first time Doosan has heard about it and may already be working on the issue. If the issue is with your machine only, at least the service tech can start trying to diagnosing it with the help of Doosan. How many hours have you put on it and was it like this from the beginning?
Sorry to be a bit late to the party, just finished looking at a DX140LCR-5. I was testing and had no problem grading, so unless Doosan changed the hydraulics, I would look at the load check/loc valves at the base of the hoist cylinders. Fixed a DX190W-5 with what sound like your problem. Basically, a spool locks the cylinder hydraulically at the base end with a 1-way valve (allows hoist oil to flow freely, but has to shift to lower the boom) it is pilot actuated from the main control valve. If one of the check valves stick, it could create that problem. The pressure in the system would have to rise to the point that feathering that control would be impossible. The other slight possibility is the boom holding valve in the main control valve, that is a fairly large poppet valve next to the boom 1 spool. I found that out on a DX225-3, the operator said it was "almost uncontrollable" when loading trucks. Frankly, i would leave both those repairs to the dealer. Can you say warranty? I understand that it could be an expensive service call, but if the machine is performing well other than grading...... Just for giggles, the 190 had a problem with the hoist not raising. After I changed both valves the operator commented that the machine FINALLY grades properly. Hope this helps! Best of luck, stay safe.
Thank you very much. I passed this on to my dealer. He is a darn good guy but like everyone else trying to run a business in America he is unable to get enough good help. The ones he has who are good are very young and inexperienced. Not sure we will continue to lead anything in the world. Our leadership is non existent at present. Thanks again.
Almost all the dealers and contractors I have interacted with for the last couple of decades have said the same thing "I'TS HARD FINDING GOOD HELP" seems to be their mantra. I am sure that the dealer can sort you out, good luck
Hi ponch458, just had coffee with another field mechanic who's older than me (like, 1 foot in the grave) he reminded me that Doosan has boom priority hydraulics, if your operator is not used to it, could be some of your problems. I will look for a way to mitigate/change that. Remembered on a 140-3 I swapped the boom and stick spools, helped a little bit. Again, good luck!
Sorry I didn’t see this last post. Thank you so much for your great replies. We have forwarded them to our dealer. Apparently the parts are three months away but they are planning to remedy the situation.