Bobcat 443B Slow boom, and makes noise when raising.

[BBaker]

I purchased a well used 443 and haven been getting it into usable shape. Prior to serviceing, the machine the boom moved slow. Book says 5-6 seconds to full raises position and it takes it about 11-12 seconds. Also it makes a lot of noise like there is air or something in the valve and lines. I changed the hydro fluid, and filter hoping that would take care of it, but it hasn't helped. It seems to run and drive ok, but the slow hydraulics has me concerned. I do not have a pressure gauge here to check the hydraulic pressure, but I can get one if need be. Any ideas/help will be greatly appreciated. I just know compared to my 753, this little one is way slow....

 

[Tazza]

Its possible the hydraulic pump is worn, providing less flow to the lift cylinders.

 

[BBaker]

Its possible the hydraulic pump is worn, providing less flow to the lift cylinders.

Could the releif valve have a weak spring and cause this? Or could I just have air in the system?

 

[Fishfiles]

Could the releif valve have a weak spring and cause this? Or could I just have air in the system?

A relief could do that , I don't see a lot of 443 , just a few but I think I remember it's got a drive belt turning the pump , it could be loose ---------- is the tilt function also effected if so then what I would do at this point is hook the flow meter/pressure tester into the aux quick couplers and flow the machine then check results against the spec book , sounds like the gear pump which operates the boom , tilt and aux is going bad

 

[BBaker]

A relief could do that , I don't see a lot of 443 , just a few but I think I remember it's got a drive belt turning the pump , it could be loose ---------- is the tilt function also effected if so then what I would do at this point is hook the flow meter/pressure tester into the aux quick couplers and flow the machine then check results against the spec book , sounds like the gear pump which operates the boom , tilt and aux is going bad

There isn't any lines or a handle to operate the aux part of the valve. I spoke with somone last night and he seems to think there may be a screen in the pickup line out of the oil tank that may be partially/mostly plugged causing the problem. So I think I will start there, and then check the relief while I have the oil out of it. I realize I am not much of a mechanic, but am a pretty good wrench at removing and replacing, so maybe with a little help I can get this thing going, as I need to use it.