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Sumitomo SH125X-3 extreamly slow hydraulics

Jari Eronen

New Member
Joined
Apr 17, 2017
Messages
3
Location
Philippines
Hi, I've got a 2003 Sumitimo SH125X-3 excavator and some 7200 hours on it. I got it month ago and have been working with it just maybe 20 hours. There was no maintenance history so first thing after arrival I changed all the fluids and filters, including hydraulic oil.

First problem occurred fairly quickly. The engine was running around 20 minutes and simply shut down. After bleeding fuel line again 20 minutes. I removed bleeding pump and changed worn O-rings and now it goes an hour or so.

Second problem appeared while I was digging a ramp. First I felt slight delay on controls and within minutes the delay became so bad that it was impossible operate. Now it's not swinging right or it will if I fully open bucket and at same swing but even in that case there's seconds long delay. Boom up is the same. If I pull control fully back there's around 5...10 seconds delay and if I release control in the middle the boom continues around 2" up and same downwards. Also if fully open stick and wait control fully pushed out the boom starts slowly travel up. Tracks and bulldozing plate are working well. No delay and plate can lift the excavator up while engine is running idle.

I checked already pressure relief valves in swing motor and valve block. Springs are ok and changed new O-rings without any improvement. There are visible oil leaks.
 

Jari Eronen

New Member
Joined
Apr 17, 2017
Messages
3
Location
Philippines
I was able to fix the problem. I had air in pilot pressure line and after I loosen pilot delivery line from control valve block out came first air and then lots of oil. I believe operating in steep ramp and I had hydraulic oil only up to low level marker. Anyway I filled up the hydraulic oil and now it's working like a new.
 
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