Well, it's really difficult to tell what's really going on if you're not there, but becuase your tpa is broken, you won't be able to adjust the point that pushes the piston on the lever blade, so to someone who hasn't had much experiences with maguras would think that the piston in the lever was getting stuck, i can almost guarantee it's not. The problem isn't the piston not coming out far enough, it'll be the prong on the lever blade not coming in far enough. However, you can replace what you have now with these: http://www.tartybikes.co.uk/search.php?category_id=53 (I'd suggest the cheapest one) Some come with a tpa, some don't. So if you decide to go with one that doesn't come with a tpa you'll need one of these: http://www.tartybikes.co.uk/product.php?pr...p;category_id=5 The whole thing would come to just over £10.