The International Cessna^® 170 Association

My 55 170B has started having very tiny rust particles in the fuel cup when I sump the tanks. I can see that the filler necks are steel. Are the tanks all steel, or are they aluminum with steel plates on top connecting the filler necks? I'm thinking I will pull the tanks to have them rolled and sloshed if they are all steel. Does anyone have experience or tips before I start pulling the tanks?

ToolHead
4424F

Tanks are aluminum. necks and cap parts are steel.

From this post and a few of your other posts and your post count, sounds like you may be a new 170 owner? If your plane has been sitting, the filler necks (like some170's) may have a bit of surface corrosion which just by the mechanical action of removing and installing the cap, may liberate the material into your tanks. Did you find any evidence of contamination when you drain your carbs fuel bowl? It's unlikely you'll find anything unless the contamination is super fine but removing the drain plug and looking might give you a warm feeling. Do you have a fuel valve drain installed? I'd ensure a liberal water check from all drains and the gascolator bowl drain and monitor. If it were me I'd continue to diligently check and see if the flakes begin to disappear with subsequent fill ups.

ToolHead, those are good suggestions above. Unless you are experienced at working on things mechanical, and you may be, I would get a qualified mechanic to determine if your aluminum fuel tanks need to be removed. Removal of those tanks is not a project for just anyone. Should you decide to undertake that project I highly recommend checking out member Jim Wildharber's detailed information available on this forum. Its quite a big job and Jim's procedures are well worth studying prior to that project. I can say this because I removed my tanks several years ago and it can be a bear of a job.

From Toolheads question about the throttle position, I don't think he's ready for pulling a set of tanks.

Yes you are correct. I am a new owner, just since Oct. Thanks for all the great info and your experiences. I will indeed refer Jim Wildharber's information. I'm pretty good mechanically, but to experience working on planes.

Again thanks,

ToolHead

Well your asking questions before diving in where you shouldn't be and finding out after the fact. That's good.

It is my opinion that a very small amount of rust depending on how much and where you found it is unavoidable. This is why we have finger strainers, gasolators and carb finger filters. Like Jim said if you find this in your carb bowl it is a whole lot more interesting than if you found it in the gasolator or coming out of the fuel sumps.

It has been my experience that the sump drains themselves can be the source of rust. As they are steal and they theoretically sit where any water would accumulate, it just make sense they rust when the corrosion preventing plating wears. Here is a tip. These drains are expendable. When they start to foul just replace them. And I don't say that lightly. And to save you some time, taking them out and cleaning them with say a wire wheel or any other abrasive means will just promote more corrosion as you will be removing even more cad plating. Takes about two weeks or less for them to be frozen up with rust again in my first hand experience.

You mention taking out the tanks and having them rolled and sloshed like you might do to your '67 Camaro resto. You can not do that to airplanes unless the process is approved by some method. Welcome to the airplane world. All parts, methods and practices must be approved.

Thanks for the advise Bruce.

ToolHead

ToolHead wrote:Yes you are correct. I am a new owner, just since Oct. Thanks for all the great info and your experiences. I will indeed refer Jim Wildharber's information. I'm pretty good mechanically, but to experience working on planes.

Again thanks,

ToolHead

Once again! Get a qualified 170 mechanic to go through your plane before you fly it. I can't believe what I'm reading. A percieved bargain is not when I see these posts of yours. Always get a prebuy inspection or at least a high time 170 owner to hold your hand when buying!! Again, park it until you get a good annual!!!! I don't want to hear about another smoking hole in the ground, EVER!!

Toolhead, the process of removing/reinstalling your fuel tanks is a big project. Just getting the fuel tank cover screws removed can dispel any future inspirations you might imagine about performing little maintenance tasks.

The gascolator in your fuel system will catch any little particles of rust, as it's designed to do. Quit worrying about the occasional little rust particle. Just drain your fuel sumps regularly and that process alone will serve the need for that matter. Trust me... your airplane ownership tasks will be numerous and lots more important than a few little specks of rust.