Hi guys. Having some trouble with a hyundai 210-7 when moving the dipper arm there is excessive load on the engine even if the arm is in the air with no bucket on . With the dipper fully folded in it should naturally want to fall to vertical so there should be no load on the engine to push the dipper out but when i push the left hand stick forward it cuts 200rpm from the engine straight away before the dipper barely moves. If you deadhead the pump when the dipper hits the end of its stroke its cutting almost 500 rpm from the engine which i think is excessive too. At first i taught my problem was in the check/anti burst valve on the dipper cylinder but i got a short hose made up and bypassed the valve but it made no odds. The cylinder was resealed recently and doesnt creep or anything so i think thats fine im thinking its in the control valve now. Any ideas?
I had a Hyundai 210 (not sure what age, maybe late 90's or early 2000's) do the exact same thing. There are a series of some sort of check valves under socket head plugs on the control valve. I pulled them out, one was a bit sticky so I cleaned it up with some emery paper and put it back in. It fixed the problem, however the machine was in a VERY dilapidated condition, so it may have been something else that just happed to come good at the same time. Good luck.
Cheers for your reply. Do you mean underneath hex/allen head plugs? I will check tommorow and can you rember were they on the front/side/top of the control valve? Appreciate your help
Yes, socket head plug that you need to use an allen key to remove. I can't remember exactly where they were located, it's a few years ago, but I got them out with the control valve still in place on the machine.
Good day Irish I believe the valve that is preventing return fluid mostly referred to as the load holding valve, if you follow the tube back to the valve chest it normally located as first valve you meet, if you post a photo of the valve chest we will try to help some more. Kind regards Uffex
Hi guys quick update. After 3 days trying different things we finally tracked it down. Went through the complete chest checked the load holding valve the 2 spools swapped hoses swapped pilot lines on the chest and in the lever swapped relief valves etc had Hyundai out and they wer also baffeled. Ended up swapping the hoses coming out of the main pumps and the problem went from the dipper to the bucket. Turns out the regulator was faulty on 1 of the pumps it was stoked up before the spool was opening and putting load on the engine. Strange that it was doing it only on the way out with the dipper and not as bad on the way in. 1 track was also a bit inclined to take off in a jump as inclined to smoothly and that swapped to the other track when we swapped pump outputs around. (Am sure its the regulator because we swapped the hoses back and then swapped the regulators on both pumps) so thankfully pumps are fine. Havent took the regulator apart yet but a new 1 is $3800!! So i reckon wel be trying a repair! Anybody any experience of this?