by Dave Reina in the July 1991 RootesReview:

sunbeam gas tanks
Thanks to Dick Keith for the photo.

Did you know that the inside of your gas tanks (both Alpines and Tigers) were painted with a black paint at the factory? This coating has perhaps allowed them to exist to their present age without rust holes. However with the age of all our cars being 23+ years, the paint is now a problem which can affect the driveability of the car.

What happens when the paint flakes?

What can happen is flakes of paint are floating amidst your gas and get sucked up through your fuel lines. They get pulled by the fuel pump’s suction and can become caught at several points in the fuel system. When this happens, the paint flake acts just like a little flapper valve and closes off the supply of gas to the motor.

Many times this restriction will allow just enough gas to pass by for the engine to idle or drive on level ground. But when you try to accelerate or climb any type of hill the engine will lack all power and may stall.

This happened to my wife and I when driving over the Rocky Mountains to our SUNI event. We were going up a very steep switchback. My wife was already nervous from the tight, narrow road with its sheer shoulder drop off when the car started sputtering and threatened to shut off. I found a little stop to pull over alongside which also had marker stones depicting where people had died on the mountain. This did not help a general feeling of nervousness. However, I felt confident it was a problem we would solve as soon as I opened the hood and looked at my clear fuel filter. I could see a bunch out of black flakes in the filter.

Having experienced this problem before with other Series IV & V Alpines and a Tiger (I’m not sure if Series I & II Alpines with their flat lay down gas tanks have painted tanks) I had installed a clear fuel filter before the fuel pump. Although it’s not always recommended to place a filter before the fuel pump, I went this way because I felt that any restriction caused by the filter to the pump was out- weighed by the benefit of preventing this junk from getting in the pump.

Also knowing that this problem can hit anytime on the road, I put in a filter that was openable. You have probably seen the kind I used in the auto parts store. It is a glass cylinder held between two chromed ends with a nylon cylindrical filter screen inside. When I opened this up in the Rockies, I found several curled up paint chips–one as big as my thumbnail (and I have big thumbs!). As soon as they were cleared out the car ran fine again.

Where else can chips collect?

There are several places I’ve seen the chips collect and stop cars in their tracks. From 1964 – on,  when the cars got two gas tanks:

  • the chips can block the fuel line at the middle of the back of the car where the fuel line is screwed to the large pipe which joins the two gas tanks.
  • The next place is the fuel pump (either electric or mechanical) and fuel filters (either before or after the fuel pumps).
  • Finally, if there is not a screen or filter in the system then the dirt and paint can go into the carb/carbs.

Dual gas tanks can be taken out and cleaned.

There are four bolts which hold each tank in place–two inside each rear fenderwell and two on the back end of the tanks inside the trunk. There are also a bunch of hose clamps and rubber connective tubes which must come off the tanks.

I start by draining the tanks from the rear underside middle of the car where the fuel line is connected. There is no drain plug–the fuel line has to be disconnected.

Then with a short, medium blade screwdriver I take off all the hose connections. Next I unbolt the tanks and remove the large springs which hold the trunk lid up. The tanks can now be tilted out of the fender wells.

I haven’t done a Series I or II Alpine in a long time, but I’m sure I will as I’ve just bought a ’60 car. However, I remember Series I and II gas tanks were easier to remove .

Once the tanks are out, they can be boiled out by one of the restoration services. Hemmings Motor News might be a good place to look, under its “Services Offered” section to find a listing for a chemical stripper/cleaner in your area.

I understand that there is a chain called Redi-Strip which is reported to do a good job. I’ve heard one person say they used the local radiator shop but that they didn’t seem to get all the old paint out.

Talking with Scott Woerth about this problem, he says that you can blast off all the loose paint with a water pressure washer. The nozzle goes into the tank through the tank filler holes and through the gas gauge sending unit holes.

Concerning the advertised tank sealants that can be poured into the tank and sloshed around to coat the walls of the tank, I personally would not recommend them because, as Scott pointed out to me, usually the inside surface is not truly cleaned enough for this sealer to adhere properly. Perhaps after a good chemical boil-out they would work. If anybody in the club has experience with the coating I’d like to hear. I wonder if there is any place which could galvanize a boiled out tank.

When reassembling, it’s good to replace the gas tank vent hose which connects the two tanks at the top, and the gas filler rubber connection. Even if these don’t look bad, at this age they are deteriorated enough that gas fumes pass through their material.

This problem can be lived with (with frequent filter changes) just so long as you are aware of its blockage symptoms if it happens to you on the road.

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