My shut off valve is leaking on my Snapper 1855. Has anybody ever replaced one of these? I have not found any info for replacement part or the procedure to replace it. It looks to be a rubber grommet/bushing with the valve. Does the grommet just pull out of the tank? There are many valves on eBay, don't want to get wrong one. There is no vertical screen on the one I have. This is such a simple thing but I don't want to damage the tank in replacement. Any help would be appreciated.