Service Bulletin HB-0113-09

Lift Cylinder Drifting Complaint

We have had warranty claims submitted to us for faulty down valves due a complaint of platform drifts down. After evaluating these valves, we could not find anything wrong with them. What we have determined is that there may have been some small particles that were dislodged and introduced into the hydraulic system.

If you are experiencing this problem, the following procedure should be performed before condemning any component in the hydraulic system.

Start by taking off the right (pump) side cover and locate the manual lowering valve. Push in the knob & rotate it counter clockwise. Release it & the knob should pop up. Next, unclip the upper control from the railing and set it on the platform floor. The reason for this is that you will need to reach the upper and lower control at the same time.

Now, push the enable button & the up switch on the upper control along with the down switch on the lower control all at the same time. Continue to hold all 3 buttons at the same time for approximately 10 seconds. What this does is open both valves and allow the pump to circulate the fluid, creating a flushing effect. Close the manual lowering valve and test operation.

I have personally found that by following this procedure, it has proven to be effective in eliminating cylinder drift.