Is it normal for fuel to non-stop gush out the fuel pump when NOT running??

[74k20]

Quick fuel pump sanity question.

New standard mechanical fuel pump on my new sb400.  When I hooked up the truck line INTO my fuel pump (carb not on yet), gas started flowing OUT the outlet (gas all over the place)  NO biggy, I quickly capped off the outlet (after gas all over the place).  But I thought fuel didn’t flow unless it was pumping?  No biggy and I ignored it (after cleaning up gas all over the place).  Then right before firing up the new motor, I decided to do a double check of the brand new QJ carb to insure there was actually a filter in the carb.  YEP…fuel gushes out NON-STOP (gas all over the place).  Carb is higher than pump, but gravity seems to be pushing fuel out with some force/pressure.  I seem to remember changing filters, lines, ect without this much fuel spilling all over thru the fuel pump.

[zieg85]

Heat may be building pressure, to you have your vent plugged at the charcoal canister?

[74k20]

74 had no canister that I know of, as I believe all is original.  It was a bit warm out tho, so maybe pressure was built up in the tanks???  It flows QUITE well out the lines. 

[zieg85]

If 74's don't have vent lines than the gas cap has to be vented.  When you remove the gas cap is there pressure behind it?

[bd]

^^^^^  X 2

The tank(s) have to be vented to breathe and properly deliver fuel - either through lines plumbed to a vapor canister or via the gas cap(s).

[VileZambonie]

Take the gas cap off when you open the fuel system. If your tank isn't vented some guys will drill a small vent hole  on the inside of the cap to cheat

[74k20]

Good points guys...both new caps, but I don't know if vented or not.  I'll check as that makes sense - thanks

[enaberif]

74 had no canister that I know of, as I believe all is original.  It was a bit warm out tho, so maybe pressure was built up in the tanks???  It flows QUITE well out the lines. 

My 74 has a charcoal canister. Its down under the left headlight. Check there.