Rust in gas tank - how much is too much -

[ZCAT3]

In replacing the fuel level sender seal on my 69S I noticed some corrosion in the gas tank. It is not too bad, but I am wondering whether it needs to be addressed now. Here are a few pictures:

[Rick Cabell]

Check your fuel filter to see if there is rust debris there. If so, it's probably time to get the tank refinished.

[VincentVega]

I just replaced the pump in my SC. I drained the tank and took out the screen, I think thats the only way to really tell what you have in there. If the screen is full of crap thats a good sign of crap in the tank.

Is there a screen in a 69?

[ZCAT3]

Chris - I don't know. The 69 fuel system is a bit different. In my car the pump is in the engine bay (it was originally in the driver rear wheel well). I did recently change the filter and although there were no chunks in it, the as that flowed back out of it was quite dirty. I may do a Por-15 tank renu process at some point, but I was hoping it was not critical at this point. For a 35 year old tank, it looks to be in good shape, but there is enough crap in there to have me a bit concerned.

[B D]

Good thread and question. To add to the discussion what constitutes a chunk? I have seen some particles in my filter after many miles but never chunks.

[drummer323]

When I dropped my tank, I was amazed at how much rust (chunks) were in the tank. I can't believe the car still ran. In my opinion any is too much! Thank God for a good fuel filter.

[Grady Clay]

Chris,

Do the right thing and remove the fuel tank for proper cleaning. Sooner or later (probably sooner) you will get stranded by the rust particles clogging the screen filter in the tank. The fine rust particles that are getting through the screen are dong damage to your electric fuel pump. The big MFI filter in the engine compartment is preventing damage to the MFI pump but is filling with fine rust particles.

Best,
Grady

[Mookster]

Based on my experiences:

Flush it, seal it and replace the fuel filter, $250.

I think this topic should be added to the neglected maintance thread.

[ZCAT3]

Grady - from the pictures I posted I presume you would recommend I also pull and clean the tank? If so, what do you think about the POR-15 fuel tank sealer product seen here: http://www.prp-porstore.com/page/por15/PROD/TankSealers/FTRK

[Grady Clay]

Bill,

I won’t pretend to be an expert on tank sealing products – I just don’t know. There is a lot on this Forum, do some searching.

You will probably need a new tank-to-chassis gasket and some new fuel line. Clean the screen filter with carb cleaner and a fine wire brush. If you need to replace the screen filter, only use the brass version, not the plastic 914 type.

Depending on your budget, this might be a good time to replace the (still properly functioning) electric fuel pump. I have read about the fuel pipes and other plumbing being contaminated/restricted. You can use a nylon gun cleaning brush system (.23 cal – .25 cal) to clean. Wait a few weeks after the cleaning and then replace the MFI filter – the old filter can catch the debris from the cleaning process.

Best,
Grady

[Randy Webb]

Mookster - I agree - do you want to post there?

[ZCAT3]

Thanks Grady - I actually replaced the fuel pump with a Pierberg and switched from a single fuel filter to a dual filter setup last week. I also replaced the engine bay fuel line. The car definitely has more pep to it after those changes. I am sorting out a bad alternator problem right now and then can tackle the gas tank. I replaced the speedo gear seals last week based on a post you wrote - that was not the easiest of jobs, but the leak seems ot be gone.

[Oracle]

Bill.
In my case the rust in the fuel tank jammed the fuel distributor piston and I was fortunate enough that a good clean and soaking cleaned it but I can tell how much damage was caused by the rust.
The fuel filter will not do anything because eventually those metal particles will make it through and most important the rust is the result of the water in the tank so other parts will rust as well...
My suggestion is to act now, get a new/replacement fuel tank.

Some have said that POR-15 will fix it but if there is a tiny little spot that you missed then you're at full risk again...

Here's a picture of my old fuel tank...



-J

[Jay Auskin]

I didn't take care of mine, and it choked off fuel flow to my engine. It would just die out after ~20 minutes of driving. I say clean it, and seal it...or have someone do it...that's what I did. I want with the Renu process.