My Mallory pump locked up after E85 use,but I bought it used about 4 years ago,and it didnt act right when I pumped the cell dry for the switch over. I assumed my Battery was low, after runnung the last race and sitting a few weeks It wont even turn. Mallory has alcohol gasket rebuild kits for the pumps and regulators and offers a rebuild service.I think the paper filters may be prone to failures as well so I deliberately left it fueled as a test.