One of our customers has a Mast Explorer H30DA-2wd serial# 2HD6378D. We cannot seem to get in touch with any one that can give ue any information on the mast construction and the type and layout of the lift cylinders. The RH cylinder does not come down properly. Our suspicion is that the flow valve or velocity fuse valve is mal functioning. We would like to know what we are up against before we take the cylinder apart. Also we don't even know where to get parts here in SW Ontario Canada. Can anyone help