2014 Hitachi zx60 with 3700 Hrs. The machine performs great when cold but after 45 min-1hr of hard use it will become heat soaked and be borderline unusable. Every function weak including swing and drives. Idling down and waiting for the machine to cool does not help much once everything is heat soaked. I have cleaned the radiator and hydraulic cooler the best I can. The engine is running at a normal temp i think, 2/5 on the monitor. Here are the temps i am getting after about 45 min of hard use. (Checked with temp gun) Boom/Stick cyl 70 deg c. Hydraulic cooler top 67, bottom 65, Radiator top 67 Deg, Radiator Bottom 60 deg, Oil pan 64 deg, engine block 71 deg, cylinder head right side 70 deg, cylinder head left side 80 deg (muffler is on left side of enigine bay). Main pump 78 Deg C. Thanks!
To my mind those temps aren't to bad. Leak or sticking relief valves or a crack on the control bank or pump can cause this symptom. It's going to be a bugger to find. Maybe if can find someone with a HiDac mapper, it would be invaluable .
You have a machine serial # ? Suggest to cycle time a few functions like high speed travel or boom up with an empty bucket when oil is cold and again after 1 hour run time. The procedure isn’t important along as it’s consistent.
HCM1NB00E00010060. Thanks that is a good suggestion
ZX60USB-3F. . From a running start, the fast speed travel cycle time over 65 feet (20 meters). Check in both forward and reverse Spec is below. . With an empty bucket and the machine in position shown below , the boom raise cycle time is 2.3 +- .3 seconds.