Vermeer 504SI Density Cylinders Stroke

I just rebuilt the density cylinders on my 504SI. When I went through the recharge process (disconnect & stroke the cylinders 12 times) the left cylinder (setting in the tractor seat) would return much slower than the right. I disconnected the right side cylinder and isolated the left cylinder and it still did the same thing. Thinking I had a rebuild issue I took the cylinder to a hydraulic shop and had it bench tested. It tested good at over 2,200psi and moved at the same speed in both directions. Thinking I may have had something plumbed wrong when I isolated the cylinders I went back and doublechecked the plumbing. I even removed and capped off the check valve & line but the cylinder moves the same, extending at normal speed but retracting about half as fast. I talked to my local Vermeer dealer and he said he has seen this before and never really figured it out either and suggested reconnecting everything back up, recharging and checking the pressure rise. I did this and I can adjust the pressure up to 2,000 psi (adjust valve pressure). I set it at about 800psi.

 

Since the cylinders don't really 'stroke' as a normal driver cylinders do but instead are pulled out by the bale being formed, do you see this as a problem?

Any ideas on what may be going on?

Vermeer 504SI Density Cylinders Stroke