98 Toyota Sienna - Leak in Fuel tank

[JC1]

I have a leak on my 98 Toyota Sienna's fuel Tank. The leak is at the top of the tank near where the filler neck enters the tank. I cannot tell exactly where the leak is, since it's a small area and I cannot get a good view without removing the tank. The tank is 3/4 full at the moment.

Gas will only leak if it's full or if the van parked on sloped pavement the rear of the tank is lower then the front.

I would be using most of the gas in the tank first, then draining the remaining gas using the drain bolt.

A couple of questions.
(1) Would a patch kits work on this type of repair?
(2) What should I look out for if I remove the tank myself for this repair?

I'm sure there are a few rusty clamps or connectors for the lines.
Should I just get a shop to repair the tank?

Regards, JC.

 

[toneydoc]

Take it to a reputable repair shop or replace it if necessary.

Don't know if you have family or not but I would not want to place them or myself in jeopardy in the event gas leaked, fumes come out, get ignited by exhaust heat or if it gets blown on muffler or pipes if you get my picture.

Pay somebody to do it correctly or replace it. Half [censored] job is not worth the risk of a catastrophic event and burning up.

Hope this helps your thinking

 

[Merkava_4]

Is that tank metal or plastic?

 

[JC1]

Originally Posted By: Merkava_4
Is that tank metal or plastic?


It's a metal tank.

 

[mongo161]

It could be the fuel pump since most Toyota's have the fuel pump located on the top of the fuel tank.

 

[JC1]

Originally Posted By: mongo161
It could be the fuel pump since most Toyota's have the fuel pump located on the top of the fuel tank.


The tank only leaks when it's full and it's parked on a slope so that the rear of the tank is lower than the front of the tank. (for example when it's parked in my driveway and the front bumper is closest to my garage).

If it was the fuel pump, wouldn't it be leaking all the time?

I do see rust on this spot of the tank, however without tank removal it would be hard to be 100 % certain. I will call a few shops on Monday morning to see what they say.

Thanks for your input.

Regards, JC.

 

[Number_35]

Some years ago I took a leaky fuel tank to a rad shop. This was out of my '85 Mazda 626 c. 1998. The people at the shop brazed or welded a leaky spot, but the tank still leaked afterwards. There were all sorts of pinholes where salty muck sits on top.

Japanese vehicles of the day (80s & 90s) used a sort of tar-like undercoating that would eventually dry out and crack, trapping salty gunk underneath.

Using a wire brush on a drill, I took the undercoating right off the entire tank, and painted it with POR-15 epoxy.

I also used POR-15's fuel tank sealer on the inside. The entire process takes several days, but I never had another problem with the tank. I did another tank a few years later on another high-mileage older Japanese vehicle (a '90 Mazda MPV c. 2000) and it also worked out well.

I will do it again if I ever have another leaky tank, but now buy the vehicles a bit newer and get them oil-sprayed regularly to delay the rust.

Each fuel tank would have been well over $500 from the dealer.

As an aside, I was very greatful to have the fuel tank drain plug on both vehicles.

 

[Doog]

Get a new tank installed. Major safety issue. Might as well get a new fuel pump while there as well.

 

[Ducked]

I patched one with fibreglass many years ago and it held for 2 or 3 years until the car was disposed of.

I'm told current formulations of petrol dissolve styrene resin. Vinylester resin is better and epoxy is probably better still, but no guarantees with any of them.

I've been told it is (or used to be) possible to get them welded or (better) braised. They orient the tank so the leak is the highest point and fill it with water or sand.

 

[Trav]

It may just be the filler neck. When the tanks leak on these its usually at the seam, that's were the rust gets hold of it.
Check this out first before tearing the tank out.