Gday all, have been looking around here for quite a while have found great info that's helped solve lots of issues with some machinery we own used around our place,thanks for all the info... Have some problems with the old ex200...has about 15000 hrs it has started feeling weak and has developed a hissing noise through the oil cooler pipes,also now has high pitched sound when operating and a rattling sound I think from the pump after its used for a while...i am not sure if I should keep spending on it or use the money towards something else...any help will be greatly appreciated.. Cheers
Gday all,really didn't explain this well I guess,overall this machine is not that bad just concerned about the issues I mentioned,not against maybe replacing the pump just concerned about the other issues it has,most likely noise in pump is cavatation.it hasn't been used much since the odd noise started,not sure what the hissing noise through the oil cooler is,could be causing problems?thought maybe someone could give me an idea of what could be wrong. Any input would be appreciated... Cheers James...
Welcome to HEF James ! I think the Hitachi's have a restrictor valve in the oil cooler return line to the hydraulic tank. Make sure that didn't fail.
Gday mg2361,thanks for the reply and welcome,yes had a look at the parts catalogue today there is 2 in this machine,will have to drain fluid again to check them, worth a look but,the parts catalogue looks a bit vague in regards to the joins in the steel piping are there orings in those or some other type seals I would have to buy genuine? thanks again Cheers James
This picture is from a newer Deere but should be similar to what you have. I don't think they sell the seals anymore by themselves. You would have to buy the coupler. The coupler should be part number 4067834 if the tube is the same diameter (about $40 US).
Thanks for the info mg2361,yes it's the same, do you know what 07 in the picture is?has a different parts number, I might check it and the oil cooler at the same time... Cheers James
That is the oil cooler bypass valve.
Gday mg2361 thanks for the info,i am still trying to rule out other issues before I go and drain the tank and start removing parts,went and got a stethoscope to have a listen around,the sound I mentioned is real loud on the pipe coming out of the control valve to the cooler,maybe the bypass valve you mentioned?also the pilot relief is louder than any other relief,pulled the cap of the pilot relief to check,couldnt work out how to remove and check thought it would pull out as an assembly not sure if I should remove to check also, borrowed some gauges will do my best checking pressures see how they are might give me some clues aswell. Cheers James
Gday all,just a quick question for anyone who might be able to point me in the right direction,checked and adjusted relief pressures all now at spec although not sure about checking main surge relief , the machine now feels a bit better,just not sure about the pump pressure at idle is only around 20-25 bar,seems like something is bypassing maybe causing the noise and low pressure,not sure where to go from here,any input appreciated. Cheers James
The pump will always put out some sort of pressure at idle with the levers in neutral. 20-25 bar sounds about right although there is no spec for that that I know of. If you have both a system relief and a surge relief, then the system relief has to be turned up by turning it in 2 turns, then adjust the surge relief to specifications, then adjust system relief back down to spec. That is how it is done on a Hitachi 120-2. I don't have access to any 200-3 information so it is just a guess on my part. Maybe @LACHAU can enlighten us .
Gday mg2361,thanks for your reply,new to forum forgive me with my reply's. I will go back through and check the pressures again, that makes sense to me now after reading through the process you explained. The manual I have says 100 kgf> in neutral for the pump although then says 40-100 when using dr ex,not sure maybe I have misunderstood the manual.thanks for your help with these issues.i will also still check the restriction valve in the cooler pipe you mentioned previously... Cheers James...
Sorry, meant to ask, would that mean that after adjusting the system would relieve though the main relief 1st then the surge relief then the reliefs for each function,i think they are called overload relief in this machine,i think they also act as anti cavatation returning fluid to the tank? if I read it right,just trying to get the working thought my own head apologies for all the dumb questions... Cheers James...
System pressure is controlled by the system relief. The surge relief protects the hydraulic pump from pressure spikes. The circuit reliefs (what you term as overload) really don't come into play except for maybe the boom down circuit which is usually set lower than the system. They protect each individual circuit when the spool for that circuit is in neutral. Picture slamming your boom down to the ground against the bucket teeth. All that pressure created from that has to go somewhere. Rather than bulge the barrel or blow out a cylinder seal, the circuit relief opens to relieve the pressure. The circuit reliefs also act as anticavitation valves.