B6000 Slow Bucket Dump Speed

[littleorangetractor]

Hi everyone. I bought a B6000 4WD about a year ago. Been on this forum since then and learned a lot from the members here. This is the first tractor I’ve ever owned.
The problem that has developed is the bucket dump speed in now very slow. Curl speed is OK. The loader is not a Kubota brand so I have no specific information on it other than the 4 cylinders rods are ~ 1-1/2 inch diameter. The trans/hydraulic oil level checks OK, the engine oil was black when I changed it, but there was no trace of water in it. There is no leaks of trans/hydraulic or any of the hydraulic lines. The hydraulic pump was replaced in the fall. When lift cylinders dead-end (up or down), or the bucket curl cylinders dead-end the engine loads up as the relief valve opens. There is NO engine loading when the bucket dump cylinders reach the end of travel.
What is likely causing this...Cylinder seals or a control valve problem.
Thanks in advance for your help!

 

[procraftmike]

Is there a filter in the system that could be partially plugged? I have had this happen with my FEL, but it sounds like your system is different.

 

[North Idaho Wolfman]

Do the lines that feed the loader have quick disconnect couplings on them?

If they do then there is where i would start to look.

If it doesn't:
To isolate the issue swap the lift hoses for the curl hoses, if the problem moves to the lift circuit it's the valve, if it stays with the curl it's lines or cylinder seals.

Does the loader bucket drift down when sitting or loaded?

 

[littleorangetractor]

Procraftmike- there is a metal screen filter in the transaxle case but I have not removed it. The transmission/hydraulic fluid was absolutely clear when I bought the tractor, however due to replacing the hyd. pump because of a cracked case and fixing a few leaking hose connections, I have cycled through about 5 gallons since I got the tractor.

NIW - There is no quick connect couplers on the loader hoses. I***8217;ll will swap the lift ports with the bucket ports to see if the problem follows.
The bucket seems like there is air trapped in the cylinder. The bucket cylinder will compress when it is loaded.
On my tractor, the lift lever is held up to raise the loader arms; down lever to lower the loader, but the bucket lever has to be held up to dump the bucket, and down to curl the bucket. Is this how the bucket connections should be... sounds like the connections are reversed.
If I can get the tractor in my shop this weekend, I***8217;ll try the troubleshooting tips recommended by you guys.
Thanks