mike515
ArboristSite Operative
My hydraulic pump (pto pump on an XT-55) is starting to make a knocking noise. It doesn't do it most of the time. It's usually when it's cold outside and when it's first engaged...even if it isn't the first time that day. It will get much louder if you move an outrigger or the boom. But it doesn't last for very long...usually 20 seconds or so if you start flying the boom. But if you engage the PTO and let it sit, it may knock lightly for a while.
I talked to a mechanic in a different state (not many in my area who work on this kind of stuff) and he said it's a piston style pump and he thought maybe the compensator in the pump is going out. The compensator is what tells the pump that a hydraulic action is taking place and it should pump more...meaning the pump is sort of passive until you move the boom, etc. But if that were the case, it would probably do it on and off throughout the course of use....not just at the beginning.
I thought maybe it was cold fluid but it will do it even after the fluid is warmed up if I shut the PTO of for 10-15 minutes. I thought maybe somehow there was air in the line so I bled the pump numerous times but that didn't help.
Also, the pressure gauge at the filter can be all over the place when this is happening. It may be in the green and move up to the yellow of it may be topped out at the yellow and gradually fall into the green area as you lower an outrigger. The oil is full and the filter is new.
So this is kind of puzzling and may be something simple but I've never seen a boom do this...even in the extreme cold or heat. Does anyone have any ideas or experience with this? Any thoughts would be appreciated. Thanks for taking the time to read this.
I talked to a mechanic in a different state (not many in my area who work on this kind of stuff) and he said it's a piston style pump and he thought maybe the compensator in the pump is going out. The compensator is what tells the pump that a hydraulic action is taking place and it should pump more...meaning the pump is sort of passive until you move the boom, etc. But if that were the case, it would probably do it on and off throughout the course of use....not just at the beginning.
I thought maybe it was cold fluid but it will do it even after the fluid is warmed up if I shut the PTO of for 10-15 minutes. I thought maybe somehow there was air in the line so I bled the pump numerous times but that didn't help.
Also, the pressure gauge at the filter can be all over the place when this is happening. It may be in the green and move up to the yellow of it may be topped out at the yellow and gradually fall into the green area as you lower an outrigger. The oil is full and the filter is new.
So this is kind of puzzling and may be something simple but I've never seen a boom do this...even in the extreme cold or heat. Does anyone have any ideas or experience with this? Any thoughts would be appreciated. Thanks for taking the time to read this.
