Gas Tank Vent diameter

[johnj92131]

Anyone have a Comanche gas tanks out of the truck that could give me a measurement of the internal tank vent diameter?  Also, how much room is there from the vent to the top of the tank.

 

I am thinking about raising the vent inside the tank to gain more tank fuel capacity like Go Jeep did with his Cherokee here:

 

http://gojeep.willyshotrod.com/HowtoFuelTank.htm

 

Any measurements would let get a head start on this little project.  Thanks.

 

JJ

[ParadiseMJ]

Well, as the article in the link says...it's 5/8"...the rubber vent hose and the tubing on the OUTside is 5/8" too.  It looks to me like all the measurements are right there in GoJeep's article, including how much you can add to go mild or wild.  It's the how to. Good luck.

[johnj92131]

Well, as the article in the link says...it's 5/8"...the rubber vent hose and the tubing on the OUTside is 5/8" too.  It looks to me like all the measurements are right there in GoJeep's article, including how much you can add to go mild or wild.  It's the how to. Good luck.

 

The GoJeep how to is for the Cherokee tank, not the MJ tank.  Suspect the 5/8 O.D. is the same.  Did not think about looking at the rubber vent hose on the outside - GREAT idea!  Unfortunately, with the Comanche, I have to drop the tank to get access to modify the vent tube (unlike the Cherokee).

[ParadiseMJ]

Dropping the tank is actually easier on the MJ than it is on an XJ. 

 

But, be advised, since you live in CA, when (if) you start looking for a replacement filler hose set, vent and filler, different from XJ's, everyone I looked at said "not legal for sale or ship to California", which is total crap.. So since the auto parts stores didn't carry it, and I couldn't buy it to be shipped to me, I just made my own. Easy enough..  The diameters of the filler and vent are the same as an XJ.

 

It's also a good idea to check out and replace if necessary the rollover vent valves ($28 each at dealer) and vacuum lines on the top of the tank.  They get old, corrode and break, crack or fall out...and you will fail your CA smog tests if those aren't working properly.