I've got a solo backpack(diaphram I think) that is leaking. This is my roundup backpack for the mowing side and cracks and bed edges. It works fine, but when I release the handle it seems to drip. It appears to stop when the pressure decrease...just a few seconds, but it doesn't shut of instantly. If you shake the wand a few more drops will come out. It also leaks some when filled to full, but not a big issue. This could really mess up some lawns if not careful. I have repleaced the tip and checked the screen(screen looked clean and ok, but did not replace. I also replaced the trigger handle. Anything I have missed?? With that said. This back pack is really old and could be replaced. Anyone got any recommendations on good backpacks? I'd be looking for a backpack that can be used for roundup with mowing. I'd also need a good backpack for lawn applications where the ride on will not fit(currently use a similar solo model as the one above). What backpacks do you guys really like?