Motorcycle Repair: push rod tube, push rod, cork

Question
Is there a trick to getting the tube to seal on 1977 xlh sporty. I just rebuilt engine and three of the tubes leak on start up. It has cork seals not o rings.

Answer
If there leaking from the top or bottom you probably have weak tube springs if its leaking from the center are you sure that you have the steel washer installed in the right order. cork goes against lower tube then steel washer then spring if this is all good then try the blue seals they are suppose to contain silicone.