75 gas tank question

[Ken B.]

I have been told that my 75 has a bladder in the tank..I really don't know what it is and what it does..Is it like a lining? Does it make the tank last longer? Thanks in advance..

[Joe L.]

Re: 75 gas tank question

Ken-----

You were told correctly. All 1975-77 Corvette fuel tanks have a seperate fuel bladder which installs inside the tank through the fuel meter/fuel filler port in the top of the tank. The fuel tank and the bladder are completely seperate parts. The purpose of the bladder is increase safety in much the same way that bladders are required and used in many classes of racing. The bladder, being more resilient and "pliable" will prevent fuel spillage in SOME cases of steel fuel tank rupture or compression.

The 75-77 fuel tank has been available in reproduction for several years now. The 75-77 bladder, however, is not currently available that I know of. It was discontinued a LONG time ago by GM and is not available in the reproduction or replacement market.

Incidentally, all 1978-96 Corvettes also have a fuel bladder in the tank. However, for these years the bladder is manufactured as an integral part of the tank and is not seperable.

[Jim T.]

Re: 75 gas tank question

Joe just this year I removed the fuel pump assembly from my 96 LT4 because of a engine miss setting a "check engine" light on the forward left oxygen sensor. I was looking for water condensation in the gas tank. I found no water on the bottom of the tank. I did not purge the tank of fuel for this. However I did see the steel tank and no bladder. I inspected the bottom of the tank for rust and found none. The engine miss was intermittent and after couple days driving the "check engine light" went off on its own after no engine miss. Several years ago I replaced the fuel pump on my 85 Corvette. With fuel still in the tank I also inspected the bottom of the 85's tank for any water. Although it has been several years, I remember it having a steel tank and no bladder.

[Joe L.]

Re: 75 gas tank question

Jim------

All 1984-96 Corvette tanks have an internal bladder. However, it's comprised of a clear material and it's fairly thin. So, you might not see it unless you know its characteristics. Believe me, it's there.

By the way, you don't want to need one of these tanks. GM list price is currently $1,914.34 and I don't know of any other source for it.