My question is: Do these have built in internal check valves to prevent back flow? I know for a fact that they will allow fuel to flow through and it seems that I remember mine having the internal check valve to prevent back flow but I need to know for certain. I did a search on the web and one source I found says they do and another says they do not. If anyone has one not installed can you check it by blowing through it and seeing if it prevents back flow. It is model 40108 that I need this info on. Thanks
Mark Jones (N886MJ) Wales, WI Waiting on FSDO inspection.
