where is the air valve on the gas tank of a 97 f150, i need to take mine off and blow it out, there is a loud hiss when i remove the gas cap and a croaking noice from the gas tank when the truck runs


next, on the air pressure thing for the rear axles, it has mud in it and i want to take it off and clean that as well, do i just hold the bracket with the brake lines with an adjustable wrench and use a 9/16's to turn it off, i just wanna ask before i goofed up

got new seals in my rear end and replaced the transfercase to drive shaft seal though very pleased with my self

 

Does it throw a code? Mine did and it was the gas cap. I bought a new MC from a dealer.

Is it the axle vent hose you want to clean?

 

no code that i know of, my air bag and 4x4 lights are on idk i have a junkyard gauage cluster and im still trying to figure out what lights are burnt out or just not on

but no code and yes the axes vent hose, the hose was cracked and off when i got the truck and i just wanna clean the fitting into the axel

 

bump please im asking the experts

 

mine does the same thing. Burps, and sucks for air when i take the gas cap off. not worried about it. No codes, so i doubt there are issues.

 

If your's is the same as my '97 F250 (light duty), the axle vent hose connects to a hollow bolt that goes through a brake line splitter into the axle. I replaced my rear brake lines last year and was surprised I didn't have any problems taking that out (considering how rusty everything is under my truck). I'm guessing the dif oil kept it lubed. I'm pretty sure I sprayed it with penetrating lube the day before though.
I was prepared for the worst though and had already purchased a new one (I think they actually had it in stock at my ford dealer).

Edit: I just remembered I posted some pics when I did the rear brake lines. You can see all the parts on this thread
https://www.f150online.com/forums/wh...-my-notes.html

 

i got the rear axel done, when i finally got it broke free i saw what the issue was, the amount of rust/corrosion on the treads was astounding, i got it cleaned up clean out and put back on with fresh hose so thats a check on my list of to do ****

as for the gas tank, gas tanks have valves that allow air in as gas is removed by the pump, other wise there would be a vacuum created by the void. Hence the hiss of air entering the vacuum, and the croaking as the vacuum becoming great enough to suck past what ever is clogging the air vent/valve.
I'm by no means a mechanic but thats just logical, the trick is finding this and cleaning it.
Does anyone know where is its located, im assuming its on the gas tank somewhere.
Who wants to sound like a bullfrog when they pull up next to a hot chick at a redlight?