Hitachi EX30-2 Overheating and Engine Stalling

[amc1794]

Disclaimer first that I’ve only purchased this older excavator in the past six months with no warranty and I’ve no experience working on it, but I’m having 2 issues (maybe connected) that I’d appreciate guidance on.

Issue 1 is that over the past 6 months I’ve found that it heats up quite quickly and within 30-45mins of normal work the red temperature light comes on. At that stage the coolant reservoir is boiling and I can hear the radiator boiling too. Reservoir contents are brown liquid but no oil that I can see. Any suggestions for solving this?

Over the 6 months it has intermittently taken to ramping down and almost stalling under minimal load e.g. tracking on flat ground or just moving the arm up or down. This issue has now become persistent and only when I leave it sitting for a few mins can I then track a few meters before it starts to ramp down and stall again. I’ve read elsewhere that it could be dirt in the filter in the inline banjo fitting from the fuel tank - is that correct?

I have had it serviced, air/oil/fuel filters changed and hydraulic oil topped up but issues are still persisting. Any ideas?

 

[Diesel Dave]

Welcome to HEF amc1794 .
Are the radiator fins clean and not obstructed also check for good airflow through the radiator. Any sign of the water pump moving coolant through the rad. The engine over heating isn't helping with the overall engine performance , I would focus on the overheat first.
I know there is generally a screen on the fuel transfer pump inlet on an Isuzu engine , not sure on a Kubota engine.

 

[Gary Layton]

This may help