genie 4047 drops a lot after raising

[jon holt]

Have a customer that had a leak on the upper cylinder of the platform lift. They removed it and had it welded. After installing it, the platform would drop about a foot after raising. Customer replaced the upper cylinder, check valve and lock valves (counter balance valves) on both upper and lower cylinders. I did find that the orifice was not swapped between the old cylinder and the new one. That did not change anything. I tried stalling it out at the full raised a few times to see if it had air in it, but still has the problem. Was just wondering if anyone has had this problem. Did try an swap the hoses on the upper cylinder and that made the lift not raise up.