Hi guys...I have 1998 model S/N:4ss01099 cat 345bl excavator.It has very weak/slow hydraulic on all functions.Strange thing is that engine runs on load but all functions are too weak/slow .When i do any hydraulic function, engine runs on load but machine is too weak/slow.The tracks moves straight but it will not turn,boom can not lift up the machine,swing function is very very slow,stick and curl also similar. thanks for input.
check pilot pressure
Hi there, are the controls any heavier than normal ? I would check the regeneration valve. If it is really bad it will cause high pilot pressure which will make the levers heavy.
Do you get full pump pressures, about 350bar? Could it be you mistake a engine that runs rough/without boost producing smoke/dropping in rpm for a engine loaded from the hydraulics?
Hi there,No i did not check pump pressure but i will do it.We bought this machine,machine was about 21000hrs.It worked perfectly about 10 days.But one day pilot pump stopped working.We opened the main hydraulic pump,we saw that some broken teeths of shaft drive ,shaft pinion,and gear.The broken teeths entered to pilot pump(pilot pump sucks oil from main pump) and stopped the pilot pump.We put new pilot pump and new parts of main hydraulic pump,we replaced,(bearing,shaft drive,shaft pinion,pilot pump,gear).After the replacement machine worked about 2 hours weak/slow and during working engine were not run under load .After 2 hours machine began to vibrate and noisy pump. Again we opened main hydraulic pump.We saw that broken plate retaining.Yes we did a mistake we put plate retainig reverse side.One piston was free from plate retainig and caused to vibrate whole machine. We removed broken particles from main pump and pilot pump..Some particles entered to pilot pump but pilot pump is working.WE replaced shaft drive,shaft pinion,pistons,plate retainings,pin centers,cylinders and gear. If i do any hydraulic function Engine runs under load but The machine was too weak/too slow.Why? If displacement between cylinder and valve plate is high machine would be weak/slow and engine can not run under load.I think pump pressure is good because engine runs under load. thanks for input.
The pilot pump is shot. Same thing happened to one I was running.