fuel tank strainer removal

russfarris · Post by **russfarris** » Mon Apr 10, 2006 2:42 am

Somehow, a lot of trash has found it's way into my right fuel tank - it appears to be organic, as in tiny bits of leaves or insects. Even after draining almost a gallon, I was still getting debris.

So the plan is to remove the sump valve and drain and flush the tank with fresh gas. This got me to thinking - has anyone ever removed the fuel strainer assembly to check the finger screen for debris/clogging? After 54 years, this might be a good idea!

My fuel strainer bears no resemblance to the picture in the IPC - it's a straight fitting, the IPC shows a 90 degree elbow fitting. I'm assuming it's a NPT thread; if it doesn't come out with moderate force, I'll leave it in.
Plan B would be to blow some low pressure air, like 10-15 psi through the fitting to knock off any accumulated trash, then flushing the tank.

If anyone else has been down this road, I'd appreciate some input...Russ Farris

N2865C · Post by **N2865C** » Mon Apr 10, 2006 2:09 pm

I had the similar problem several years ago. "Appears to be organic" is a good discription. Tiny flecks that would not go away. I was told by an A&P that it was caused by a type of fungus that can live in the gas. I have no idea if that is true or not, but he did say it with a straight face. I drained the tanks out the sump (I did not flush them, but that sounds like a good idea) and the problem was gone.

Post by **GAHorn** » Tue Apr 11, 2006 1:04 am

There are bacteria that can live in water (keep your tanks sumped), and eats diesel and jet-fuel/kerosene. The body-wastes can produce a bio-mass/matt that can be "junky" and clog filters/screens and cause corrosion. I've never heard of it in gasoline tho'.

There are commercial products which control/kill the bacteria, one of which is produced by the old "Twenty-Mule Team Borax" folks, ...called JB-Biobor. I've purchased it at Aviation Supply houses for jet fuel.

Russ, do you/have you used autogas? (Not trying to start anything, folks. Just trying to search for causes/solutions that I've found previously.)

russfarris · Post by **russfarris** » Tue Apr 11, 2006 4:35 am

Sure George, you're not trying to start anything

Yep, pretty much autogas with an occasional fill-up of avgas.

I drained the tank today...I identified a leg and part of a wing, so the current working theory is some bug made a bull-eye hit on the fuel vent and ended up in the right tank.

Like George said, I've never heard of bacteria living in gasoline. In the mid 1970s working as a lineboy, I remember using Prist in Lears to kill the bugs.

Removing the fuel strainer was a non-event. Came out easily, and the coarse wire finger screen looked perfect. Unless you suspect a problem, I wouldn't bother removing it. Installed a new CAV-170 drain while I was at it, since the old one was seeping (autogas???)

Thanks for the input, guys...Russ Farris

Post by **GAHorn** » Tue Apr 11, 2006 4:39 am

Ha! Well, just to make you feel better, my right CAV-170 will be replaced before Kelowna. It's dripping AvGas.

BTW,...Prist no longer claims to fight bugs (bacteria/fungus) in the fuel. I've been anecdotally informed that the bacteriacide has been removed as an ingredient. Prist only claims anti-icing properties these days.

Also, (some of you guys are gonna love this one...) I have an "undocumented" modification to my fuel system. I discovered one day (while fooling around with an empty Alcor TCP can) that the screen/strainer at the bottom of the pickup tube in that can is EXACTLY the correct size for the gooseneck fuel vent in a 170. The screen is "hat" shaped...just like a top-hat.... so it's body fits right down into the tube with a nice friction fit, ...but the "brim" prevents it from going on down into the tube. It's made of fine-mesh stainless steel screen. No bugs larger than a molecule of air will get down there. It's been at work on my airplane now for about 4 years.
Now I once mentioned this before, and someone out there contacted me and asked me for the next screen that came out of my next can of TCP, and I told them I'd send it. The problem is: I didn't buy anymore 1 qt. cans of the stuff....I bought it in 1 gal. cans which don't have that pickup tube. (And I can't remember who I made that promise to, so I can't contact them to apologize and explain. Is it someone who's reading this now? Please contact me.)

N170CT · Post by **N170CT** » Wed Apr 12, 2006 3:26 pm

George,

C'est moi.

But if you do find one, I'll be happy to pay for it

.
chuck

mrpibb · Post by **mrpibb** » Sun Apr 16, 2006 3:15 pm

Hey, don't discount the possibility of the fuel float deteriorating. I was getting little specks of matter out of my left sump, this occurrence almost hasn't happen as I don't let my left tank ( only 12 gals) get low to were the float bounces and vibrates on the tank bottom. this is my sop until I get into changing or resealing the float.