Jeep YJ Gas Tank Capacity Conversion:Increase Gas Tank Capacity from 15 to 20 Gallon(56.7 Liters to 76.7 Liters) in less than 30 mins!

Daimler Chrysler made only one tank for the YJ  (1991 to 1995)and if you did not pay for the extra capacity option,they installed a longer vent tube in the tank which "fooled" the pump at the gas station and forced it to shut down at 15 Gallons (56.7 Liters),leaving the extra 5 gallons(20 Liters) impossible to fill.
The fix is simple.Loosen the lug nuts on rear driver side tire .Release vapors from fuel filler capRaise the Jeep on the rear driver side and remove the tire.(Safety First regarding jacking) Remove the plastic shroud that covers the underside of the fender in the wheel well.(Plastic Rivers hold it in place) Locate the two hoses in the back of the tank.The  vent hose is smaller than the filler hose.Unscrew the clamp,pull out the hose and locate the  inner vent tube that sits flush inside the tube that the vent hose clamps on.use a screwdriver to deform the inner tube enough to get a good grip with needle nose pliers.Due to limited wiggle space it will require some effort to pull the inner tube out a few inches.After that you can grab it with your hands and pull the rest of it out(about 10 inches or so).You can either trim the inner  tube to 2 1/2 inches and put it back inside the outer tube or just leave it out totally;you really don't need it. Put the vent hose back on the vent tube,screw it tight(just a little tight;don't over tighten) Replace the shroud ,put rivets back in,put the tire back on,tighten the lug nuts to correct torque ,lover the jack/jackstands ...and...you're done!!!!!

Torque Specs :as per Suspension U-Bolt size (S.A.E.)

3/8" -   30 ft. lbs  

7/16" - 45 ft. lbs
 
1/2" -   65 ft. lbs
 
9/16" - 95 ft. lbs
 
5/8" -  125 ft. lbs
 
3/4" -  225 ft. lbs
 
7/8" -  325 ft. lbs
 
1" -     625 ft. lbs