OhCustomer I sympathize with your situation and I understand your distress.
Tell me, is your fuel tank metal or a compressed fibre?
The reason I ask is to determine the flexibility of the material used in the construction.
Most newer tanks are a fibre, not a metal. This is partly to reduce cost but it is also partly to reduce weight and ribs in them are there to provide strength.
So, can you tell me if the tank you kept has any visible signs of collapse when looking at it from all angles?
Also, do you have the original paperwork from the first collapse, one that includes a Toyota Part Number?
Did they also replace the charcoal cannister in the engine compartment, or say anything about it in the paperwork or verbally when they gave you a diagnosis.
Collapse of a gas tank is a seldom heard of thing, I have had tanks that leaked, never one that colllapsed.
The way your fuel system is supposed to work is pretty simple if you forget about the car running.
The gas is stored in the tank where the pump sends it to the injectors under pressure where it is vaporized and injected into the engine. The unused gas, there's always more being pumped than your engine can use, is allowed to flow back to the tank and the gas vapors are sent to the filter cannister under the hood where they are recombined and sent back to the tank too. All this happens without you know what's going on because your engine is a closed system that only takes in air thru and intake system that measures the amount of air that enters.
If you got all that then you will understand that in order to collapse a solidly constructed fuel tank that is made to exacting specifications you would need to be pulling a vacuum supplied by the operation of your engine and the pressure of your fuel pump that was strong enough to cause your tank to fail.
Something sounds fishy here.
Could it be the dealer???
AnywayCustomer get me the answers to these questions so I can try to figure this out for you. Like I said, this sounds a little fishy. Strange or odd anyway.
Let me know, and
Thanks for using Just Answer
This is one of the really good questions.
P.S. Write me AFTER your route. It's late and I'm going to sleep in tomorrow.. jdm