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If someone can help me understand the expansion bowl and the vent fittings at the rear driver side of the tank.

From the two external vent fittings, is there an internal hose/tube that connects to the vent holes on the expansion bowl, or are the expansion bowl's two vent holes open to the tank?
The soup bowl has no lines that go into it. It just has the two pin holes in it. Again, the vent lines do NOT go into the soup bowl. If you coat the inside of the tank the only problem you may have is plugging up the two pin holes and then the soup bowl will do absolutely nothing other than take up space. Also to answer your other question, the two vent lines get tee'd together and then connected to the filler neck, the third one used to go toward the front of the car and connect to the charcoal canister. We should not re-visit this, it has been discussed many times on the forum. We have to find one of the old threads and just link to it - found a good one read the whole thread. Most of them are associated with gas smell inside the cabin.
 

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Opeler
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Discussion Starter #22
Thanks Mark, tracking all. So if the two vents were clogged up, there would be no issue with venting?


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No....its not a Buick....
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Is this bowl mounted under the filler neck? I'm confused????:thinking:
 

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Is this bowl mounted under the filler neck? I'm confused????:thinking:
It is inside the tank, I believe on the passenger side toward the front of the car near where the vent line goes into the tank from the outside. It is spot welded to the top of the tank. If you have a tank that is nicely cleaned up you can see the circle of spot welds on the top of the tank.
 

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It is inside the tank, I believe on the passenger side toward the front of the car near where the vent line goes into the tank from the outside. It is spot welded to the top of the tank. If you have a tank that is nicely cleaned up you can see the circle of spot welds on the top of the tank.
So from Gordon's pictures you can see I was wrong and that the soup bowl is on driver's side with the fuel level sender.
 

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I have coated both my fuel tanks myself. My 72 has three vent lines and the 69 has two vent lines. I used the POR-15 ( Paint Over Rust) kit sold at most Auto Parts and Body Shop supply houses ( or online) Once you clean with Marine Clean the metal prep (included in kit) let dry then you coat. I let the tank dry out real good ( a week or so) or use a vacuum cleaner in the fill tube to evaporate moisture.
I coated my tank on a hot summer day. I plugged all the openings, Then Pouring in the coating and rotating 360 degrees until all the surfaces are coated. pouring out the extra.Then let dry upside down..this will drain anything left in vent bowl
I never had any venting issues with this method, except when the canister clogged on the 72 GT, and cause a vacuum lock, and stalled the motor...no fuel to carb.

My vents now exit bottom of the car and vent to atmosphere, just like the 69 GT does ( no canister) see photo of aluminum vent line under car next to rubber boot.
Vents are made of aluminum and are pitched to prevent trapping fuel. After years of repairing cracked and broken vent lines smells inside my GT's I find this the best way to resolve the problem.
When the canister clogged or faulty there is no real replacement. Just my Thoughts here.
 

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Just dropped the tank from my 73 Manta. My fuel filter was getting clogged and fuel color was red. Once it was out of the car I shook it a bit and what looked like coffee grounds came out. Also found a rag in there that the PO must have been used as a temporary gas cap (oops!). Found out why my fuel gauge didn't work. It was seized up do to corrosion. Luckily the spare parts that came with the car included a NOS fuel sender.

I am looking for a shop to clean and line the tank. The tank looks almost new outside and has no leaks. It's just the side that needs help. There's a radiator place that was recommended to me but it is a 90 minute drive each way. Found another radiator shop only 15-20 minutes away but he says they don't guarantee the work anymore do to inferior lining materials available compared to the past (epoxy). I'm going to bring the tank to him to have him take a first hand look and see what he recommends.
 

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I noticed there appeared to be no gasket at the sending unit connection to tank. Is this correct? The FSM gives no details about changing the sending unit.
 

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I noticed there appeared to be no gasket at the sending unit connection to tank. Is this correct? The FSM gives no details about changing the sending unit.
There is a gasket for the sender. OGTS has them. I just got a kit from them that included the gasket, new rubber filler hose and the vent lines and tees. I'm sure you can make one. I can get you the name of shop in Methuen, MA that was referred to me by a neighbor. The local places want to use the red tank liner which is not what I'd like to use.
 

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Opeler
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Moyer Fuel Tank Renu - antique gas tank repair restoration, classic car gas tanks GASTANK

Yep, you have to ship the tank to them, but they have instructions on how to safely do that.

I have used them before and would do so again.
I agree with using the RENU process on a tank. A local RENU shop redid my old Porsche tank last year and did an excellent job. Before blasting, they cut inspection tabs in the tank so that they can see and reach all sides of the tank and between the baffles with the media blast nozzle. Then they re-weld the tabs closed. They also repair any rust holes or leaks that they find and pressure test the tank.

Finally, after blasting and repairs, they coat the interior with tank liner and coat the exterior with Dragon Skin coating, then put the tank in an oven to cure the coatings. There is a lifetime warranty on their work.

Mine cost $450, but I wasted nearly that much trying to clean it by a halfway measures, like repeated flushing. Residual rust, varnish and tar in the tank plugged my electric fuel pump, filters, lines, and fuel injectors.
 
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