Caterpillar 303 CR Travel Valves Leak (Part 1)

My Caterpillar 303 CR leaks hydraulic fluid from the travel valves. It has done this since I bought it and I suspect quite a while before that. With the help of my Dad we dig in to see if we can get it fixed. Having never done this before and not finding any technical data we muddle around for a while trying to figure this out. Mistakes are included in the video.