topdog63

OK so I've notice ed that whenever I take my fuel cap off u get a long hiss from air pressure that has built up in the tank and its quite alot of air releasing. What causes this and is it anything I should be concerned about?

drmix

Im sure its normal mine does the same thing too. The fuel system has alot of pressure that builds up.

I wouldnt worry about it. I think that it would be better than not having any hiss at all meaning a possible leak somewhere

BMcEL

Normal.

[/THREAD]

WHAHAHAJR

I'm having the weirdest deja vu right now

ahhhh... figured out why
https://www.yotatech.com/forums/f120...on-lot-248643/

thatsmyYOTA89

like drmix said i would worry if it didnt. i cant remember a time that mine hasn't hissed when i took my cap off to fill up. it will release more air if you wait longer to fill up also ha

zerokelvin

cause: Fuel systems are designed with a sealed system in attempt to prevent fuel from being released into the atmosphere. As you drive your truck around.. using fuel->emptying the tank a bit-> this CAUSES a negative pressure in the gas tank. When you remove the cap (break the SEAL) air is being sucked (actually pushed, but we won't go into that) into the gas tank and you hear that "hiss". It is perfectly normal and it also lets you know your gas tank is sealed and working properly.

concerns: You should have ZERO concerns about this as the system is designed to function as you described Have a nice week

topdog63

Thanks guys
BMcEL I sent you a pm the other day. When you get a chance can you check it out and respond.