The other night at work I tried pressurizing my fuel tank to try to find my leak in the supply system. It didn't work very well because it seems as if there is a vent line up near the tank. There was a small rubber hose that follows the filler neck and I pinched that off and still all the air I put into the system escaped right at the fuel tank somewhere. Is there a vent hose somewhere that needs to be pinched off? What is the proper way to pressurize the tank? Thanks in advance guys!

 

get your shop vac and put it on blow, stick the hose in your filler neck. make sure to clean out your shop vac good first.

edit: I haven't done this but it seems like it would work

 

Most aluminum tanks don't want more than 2 psi test pressure. I'd be careful with plastic.

 

I take it your trying to pressurize your fuel system to look for leaks? Take an old filler cap, drill a hole, Tap 1/4 pipe. use your regulator to keep it @ 3-5psi.

You will have to block vent best you can. you're going to have some other leaks at the tank. This is where the regulator comes in.

listen along your fuel lines, fuel heater and lift pump.

 

I use the method Timmy describes exclusively for finding leaks, filling and bleeding the filter. There is a vent on top of the fuel tank but most compressors have no problem keeping up with the amount of air it leaks. The vent hose by the filler hose stays pressurized.
What I've found that helps immensely is to have the tank as full as possible otherwise it takes too much air.
I set my regulator at 5psi.

 

OK, thanks for the info. Hopefully I can make some progress on finding my stupid priming issue.