Okay so just put in new front tank and new rear 38 gal tank. Also put in a new tank selector valve.

Ran the front tank down to fumes, filled the rear and switched. Thought my gauge was messed up as I only drove 45 miles and my gauge was down past 3/4. Shouldn't do that even on 19 gal tank. Switched tanks and front said full.

Long story short, I pulled my dash apart to find nothing. Went to get fuel and I was able to put 20 gal in the rear tank that should have only been down 3 at the most.

Question is if the return for the rear tank is plugged will it automatically return to the other tank? It's a bran new OEM for selector valve and I can hear it switch as soon as you flip the dash switch.

 

Sounds like a bad selector valve or plumb wrong

 

Well the valve is new, only been on maybe a week. I checked the lines and they are connected correctly.

I disconnected the rear return at the valve and blew air back to the tank thinking maybe it was plugged. I then blew air back from the return by the engine bay to the selector valve and it came out of the port that I had disconnected. We will see what happens now I guess.

 

Just cause a part is new doesn't mean it's good

 

Disconnect both tank return lines from the valve and back-blow the return from the engine again. Make sure air is only coming out of the rear return port on the selector, not the front port at the same time. Throw the switch to FRONT and check the same thing (should go to front return only). The return side might somehow allowing fuel to go to both.

 

I did this two days ago and also blew back to the tank. Might have been something plugging the line I don't know. Drove the truck 30 miles last night, doesn't appear to be returning to the front anymore. Problem fixed.

Now my toe in is off and eating my front tires. Rotated them yesterday so looks like I will be making an appointment at the alignment shop.

 

IIRC, it's the camber that eats the tires on these TTB trucks, not the toe. And you have to find a shop that knows how to set the camber on it.