The International Cessna^® 170 Association

I want to remove fuel tanks on my 170A. Who has the best price for the two filler area gaskets? Where do I find NAS228 screws?
Thanks
Dave

N73087 wrote:I want to remove fuel tanks on my 170A. Who has the best price for the two filler area gaskets? Where do I find NAS228 screws?
Thanks
Dave

NAS228 - I assume you are talking about the fuel tank cover screws? I'd get in touch with D&D Aircraft Supply and get a stainless steel screw kit. ( http://www.ddaircraft.com ). Gettin' those old buggers out can be a royal pain in the butt.

The screws need to be structural grade. Not sure about the A model but the B model uses two different lengths. Some " Blaster" from NAPA will help losen the old screws, and a "screw nocker"used very carefully, will get most of them. Some of the rear and outboard ones can be reached with vise grips from the inside of the wing after the heads have been broke or drilled off.

I just removed my RH tank last week and pulled my LH tank last year. As stated above it can be a B@$^h of a job. Do a search for "fuel and tank and screws" and you will find some good info. This time I put I put some WD-40 on the screws the 3 days before and the night before and I think that may have helped. It's a good idea to have a tap handy to chase the threads if necessary when you put in the new screws. I also used a SS kit from D&D as recommended by my IA and I'm very happy with it(Waiting for incomming from George ).

getting rusted screws out can be great fun, many owners can't believe why all that labor time was needed, "all you had to do was look it over!"

for the first step if you have time, use penetrating oil at least a day in advance. my favorite is Mouse Milk, others are Kroil, WD40, Liquid Wrench, etc. let them soak.

then for a tool, I use a speed handle with a Snap-On ACR bit or a drywall bit - the snap on bit has little grippers on the flutes to grab the screw head, the drywall bits are pointed to get down into the screw and grip it good. #2 size screws, don't try using a #1 phillips bit or you'll just cam out the heads (rip out the head). use the speed handle to allow you to lean down on the screw and get a good grip while you turn it.

if it still doesn't move, and BEFORE you start slipping in the head, put some valve grinding compound on your bit - more extra grip.

try TIGHTENING the screw a tiny bit, sometimes that loosens up the threads enough to then remove it. take it slow.

any screws that get cammed out, you can try a #1 ez out, or cut a slot into the head with a dremel and try a regular screwdriver bit, or give up and drill the head off. rats, more work.

can't get the remains out of the nutplate? drill it off and install a new nutplate. same goes for rusted nutplates. these are probably supposed to be locking nutplates, so you shouldn't really run a tap through them - but I've seen it done

new screws - I'd use the proper MS screws here, preferably MS27039 if you want some with grip length or MS 35206 if not, these have the raised heads with deeper area for your screwdriver bit, you'll like them next time coming out. ss screws aren't actually supposed to be structural, and these are kind of important (not just insp covers here). plus ss screws are actually easier to cam out the heads, and the threads never seem to be quite right so you're always feeling like you are crossthreading them in anyway. (although as it was explained to me once, "crossed threads are as good as torque")

wow, no wonder I charged you all that labor. sorry about that, hopefully it's better the next time out in 50 yrs

In addition I've used a battery operated drill with a clutch so that it acts as a mini-impact wrench. Really works. Well, sometimes anyway.

Use proper MS screws. No stainless here please.

WHOOO-HOOOOO-HOOOOOO! CAREFUL using electric or battery operated power tools on the fuel tanks or anywhere near fuel. SPARKS!
Use either air-tools or hand tools.

I've spent enough time and patience on removing rusted tank cover screws to feel that a guy would have to be a real masochist to install other than stainless screws. I realise that the screws are supposed to be "structural" screws, but there is about fifty or sixty screws in each cover and I consider that enough overkill to justify the use of the stainless screws.
I wouldn't, of course, make a log entry about it, but then, my opinion is that log books are too cluttered up anyway.

gahorn wrote:WHOOO-HOOOOO-HOOOOOO! CAREFUL using electric or battery operated power tools on the fuel tanks or anywhere near fuel. SPARKS!
Use either air-tools or hand tools.

Thanks George, very good point A bit of brain fade on my part and I've never used the electric clutched dill near the tank but have in other areas.

But then how does one use the Dremel with a metal cut-off wheel to slot the heads? I guess you don't. There are ways to protect the tank from igniting that have been discussed here before.

I know I could remove my tanks pretty easily as I have to tighten the screws occasionally. I guess someone decided to use a tap on the nutplates at one point.

I've heard that this tool works well for removing stubborn screws: http://www.aircraftspruce.com/catalog/t ... ractor.php

n2582d wrote:I've heard that this tool works well for removing stubborn screws: http://www.aircraftspruce.com/catalog/t ... ractor.php

I used a similar tool and it removed screws that I'm sure I otherwise would have had to cut off.

Check with Velvet. She has an Association CD that covers fuel tank removal and associated repairs with lots of color photos and helpful hints. It was being sold at the Dearborn Convention for a very reasonable fee.

Hey Jim W., are you sure your B model is a 56? I thought 55s went to about serial number 26997 or thereabout.

Do yourself or the next guy a favor and spray the screws with LPS2 or the like prior to installation. A bit messy but in my experience it keeps 'em from "freezing in place" for years.

Steve

Tracy, Yup it's a '55 model year You are the first to catch that my profile was wrong. Jim W