Hi. My first time on here but you guys seem to know your machines. My Hitachi Ex100-3 has developed a very annoying problem. Basically first hour of operation is perfect as usual then hydraulics go very slow. at first it will be just for a split second but will get progressively worse and after another hour of operation it will be slow most of the time. At its worst it could go from normal to slow 5 times in 20sec.sometimes it will stay slow but if I give the boom a quick drop it goes back fast for a few seconds again.. I have bought a new solenoid for top of pump and tried it in both places with no improvement.. there seems to be 24volts to both seconds also.I have had wiring probs a few years ago due to hole in exhaust but cant find any damaged wires now.Also I get this pulsing noise from behind cab like a pipe pressurising very high very quickly then depressurising immediately. this repeats about every 5 second when warm. I would appreciate any help you guys can give as I am a one man band and need to get this sorted or will start loosing much need work. Thanks in Advance.
Do both tracks run slow too???
Do both tracks run slow too???If not then it must be pilot pressures because each track runs off a seperate pump.
yes both tracks run slow.. everything is slow fast,slow fast .... if you know what I mean
Sounds like a relief valve problem,thats where I would start
Thanks for your help. I will check it tomorrow.. is it located on the pump.
hello jimmy i think your machine heat up during first hour. first of all you check both main pump main pressure & pilot pressure in first start (good working condition ) then you check these pressure when operation is slow. if you give me these result i can help u
No. Just one pump.
The pulsing is the pilot system, completely normal. If you figure this out you'll be my hero, I'm one of the crowd with the same problem. Brandt's relief valve suggestion is a good possibility, as is something in the electrical system.
I would be checking the pump angle sensor as it is common for these to play up when they get a bit of heat through them and cause the hydraulics to go slow. Also the engine speed sensor may be worth looking at.
so what ended up being the problem i have the same problem with my ex100
My ex-60-3 had the same problem when the machine lämpesi its power declined. and it came to repair the cockpit under the pilot control box is a safety valve, and it was dirt, it provides pilot pump pressure Which Must Be 45bar + -5bar speed 3.i am Finnish guy and I Hope that this was helpful.