shannon3115
Member
New to the group. First big excavator. I’ve got a 1988 hitachi ex200 lc. Bought it new it had a crack in the radiator. Could only run it in the yard without being able to dig with it, just going through the motions. Had the radiator rodded, cleaned and repaired. Changed hydraulic filters in the tank, they were dirty. Changes the pilot filter. Changed oil and filter and thought I’d be ready to go. I can run the excavator digging shale rock here in tn for about 30 minutes , and I start getting some hydraulic whine and a little shutter. Every hydraulic function is effected, even final drives trying to track is effected. One mechanic told me the main hydraulic relief valve was bad, so I replaced it. Still same issue. Seems the harder I run it the sooner it happens. When I dig dirt it takes longer to happen. Seems like the harder it strains, the sooner it happens. Or when I dig shale, I do more repetitive short passes before I scoop a full bucket and load into a truck. I took a heat temp gun and have even temps at my oil cooler and pumps and at reservoir. Doesn’t seem my hydraulic fluid or pumps or reservoir are excessively hot. Just curious if anyone has any suggestions where to start checking. TIA