# Liebherr Excavator



## 4theroc (Jan 28, 2007)

hey guys. Lookin at an old 1984 912 Liebherr excavator. Its a county machine but they tell me the drive motors for the tracks are slow. I know alot of you guys arent mechanics, but how do u know when then things are about to go out completely. ANy idea of what it might run to fix it. All I plan on using the machine for is loading topsoil at my lot where I keep my equipment. I dont plan on using it to for work.


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## Elast (Apr 4, 2007)

Hey Roc, you should be cautious whenever anyone tells you that one of the most expensive parts of the machine are showing signs of failure. As far as being able to tell how far gone the drive motors are or even if the drive motors are the problem can only be done with a flowmeter. You could try and get the cycle time tests for the unit and do those which will give you a prelim result to base your decisions on. If the cycle times are down on all functions is is a symptom of low pump FLOW not pressure, if the cycle times are good then it mat be a symptom of pressure. Without real solid test results you could be buying a very large paperweight. They have told you that this problem already exists, what are they not telling you? As far as cost is concerned you need to know where the problem is. If it is a pump then it could be 15,000, a drive motor 5,000 or just a 500 releief valve. Impossible to guess at. Who knows maybe issue is not hydraulic maybe engine down on power. Remember RPM=GPM
Elast


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