Gas spills out neck when full

[Master7122]

When i fill my comanche up to full, gas shoots out of the filler neck then it stops. Is there like a check valve that could go wrong? It used to stop the gas pump on its own... been doing it for about 3 fill ups now. It’s a lwb if it makes a difference with tank size

[HOrnbrod]

The tank vents (2) are probably inop need to be replaced. They are on top of the tank. Get the rubber washers they fit into also.

 

https://www.quadratec.com/products/51315_9001.htm

 

            

[Master7122]

13 minutes ago, HOrnbrod said:

 

The tank vents (2) are probably inop need to be replaced.

 

Thank you! Judged ordered the 2 valves and gasket

[ParadiseMJ]

There are also two hoses going into the tank at the filler.  One is the Big one, the other is a 5/8" vent hose (can't see it unless you get under the Jeep with a flashlight. 

Don't know for sure, but it could be backing up there too. 

 

https://www.extremeterrain.com/omix-ada-fuel-neckfits-both-yj-1774303.html?utm_content=XT%20Engine%20and%20Performance%20-%20Other%7COmix-ADA&T5_Var4=J12443&intl=0&utm_campaign=XTW+Wrangler+Vehicle+Medium&dialogtech=ppc&utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&T5_Var3=orange&gclid=Cj0KCQiA8f_eBRDcARIsAEKwRGcX3yUgNZc9_RC6MNN4DN6fEVSO2a25Y0JuQbAPboDTMbfdsbeRjJ0aAjtyEALw_wcB&gclsrc=aw.ds

 

This one is from a Wrangler, (and it's upside down)but you can see that there are two tubes going in.

[gogmorgo]

Just to illustrate the vent hose:

Ignore the shiny new XJ tank on the left. The old crusty one on the right is a LWB 23-gallon MJ tank. The bigger hose is the filler neck, the smaller one beside it is the vent line. 

Also visible are the two tank vents Hornbrod mentioned, the two round things on the top of the tank. 

If the tank vents are clogged, it allows pressure to build up in the tank, which blows up the vent hose. Once the level of fuel in the tank hits that vent hose, the gas gets carried up with the air rapidly exiting the tank. 

I pumped gas back in high school. Due to how much gravel cars saw where I lived, so many of them had clogged vents. That fine rock dust just gets everywhere, so you start figuring out tricks to get gas into cars. I never could get gas to flow at full pump speed into my MJ. Pull the nozzle out slightly to allow vapours to vent, and down pull the pump handle wide open, or set it to a less open stop. Listen closely to it, so you can slow it down if you hear it starting to gurgle back up. Just some suggestions if you need to get gas before you get the vents installed. You don't want to be forced into doing that every time, though. For me it was all well and good until I drove it to California, where they have a boot over the filler nozzle to stop vapour from escaping, with a switch that shuts off the pump if you don't have it pressed up against the fuel filler. On some fancier stations there was a vacuum in the handle to draw out vapours, but on many it was just a sealed boot that forced everything out through your evap system... Getting gas was difficult sometimes.