Just recently got this excavator. Worked fine then stopped swing and travelling left track without warning. Fluid level is good. It makes no attempt to swing or travel left track. No change in motor while trying to swing or travel. Right track travels fine, main boom operates fine, dipper not fully operational. Any suggestions where to start looking for problem?
Check hyd filter
Pump destroyed all 9 pistons. I rebuilt pump. It works, but seems to be building up internal pressure and blew the gasket. All lines are clear and the filters have been changed. Any Ideas?
You probably have pump debris in some of your valve body components. Pull and inspect your relief valves.
I'm new at this hydraulic repair, where are the relief valves located?
If this were my machine and I had that type of failure, I would pull the main control valve completely apart. It's the huge metal block in the middle of your machine with all the hoses and tube lines on it. If your new to hydraulics, I would get some serious help with it.
Thanks. I'm working towards that.
I don't know if it was a 51u , but it was an new 85. 225 with 3208 eng what a pos! It had the new style single pump. It was a fast machine but suddenly it would slow down so much it barely moved making a loud foghorn noise. I had to shut it off and restart, sometimes repeatedly multiple times a day. I called it Moaner. That year ho penn mechanics spent a lot of time on site trying to figure what was wrong! Even the shop mngr came by often giving me a cat hat every time, I got them all over time. They changed the swing pump and alotof other parts to no avail. Apparently there's a small air pump to charge hyd tank that they changed. It worked much better but not totally. The noise, to me sounded like cavitation in pump, making sense to change air pump to charge hyd system. IMO if I didn't shut it down it might have burned the pump without hyd oil! Keep this in mind when repairing yours. Check the little air pump on yours! I don't know what happened to machine as I only worked 1season for its owner. Just a wag as I don't know what finally happened to it . Good luck! Take hyd oil sample to Cat, have it checked for particulates,