mines it leaking pretty bad, its almost entirely empty after about 10 days. it's not the aisin one, i can't quite make out the name of it. anyways, i was looking at them on MAF's site and they're $220 and not even AISINs!?! pre 1975s are half that price. what's the big difference? i've never had to replace a brake cylinder before so this is going to be a learning experience for me and i'd like to make an educated decision. thanks.