Bobcat 909 backhoe unit

[akmike]

Hi, I have a 909 backhoe that the boom bleeds off as soon as you lift it and release control. There are no visible leaks on the outside of ram. Where to start looking for problem in control unit or packing in ram?

 

[Wayne440]

The simple answer is "yes" - pick one and start looking. IF it was mine, I would probably start by checking the cylinder.

 

[foton]

not that it means much but I agree. cylinder first.

 

[Lowe.Buuck]

There is a simple procedure for testing cylinder piston seals. Disconnect the hose at the base end of the cylinder and cap the hose and the cylinder connection. Attempt to RETRACT the cylinder with the control valve.

If the cylinder EXTENDS the piston seals are bypassing.

Technical explanation in attached video.