The International Cessna^® 170 Association

I have my fuel tanks out for service. Has anyone changed the fuel fill to one that does not have the depression that looks like it holds water? Does water get into the tank from this fill? This is on a 49A model.

Monarch has a mod to cover the "moat". I'm not at my home computer and cannot give the web link.

Thanks for the info, as you can tell I'm new at this. As I looked at the tanks the tops seemed to want to collect water and there is a mod. Am I being too concerned about this? Is this a usual change that 170 owners routinely do? I decided to change the screws on the tank panel to SS, then cleaned and inspected the tanks, they are in very good condition, but the "well" around the tank looks deep. Suggestions?

I had minor trouble with water getting into may left tank after days of rain with the old "well" holding the water in place and allowing it seep in. I installed the Monarch "riser shield" and caps and have had no more trouble. As Gahorn sez, it covers the "moat". So it's a good and fairly cheap mod if you have trouble with water seepage. Also good is the fact that you don't need an IA to perform paperwork. Owner is allowed to perform the installation.

Yes, I would be concerned about water intake in this area. I used to think my '54 was taking in water via the factory vent tube, or I just had a lot of condensation on the inside of the tank. I always get more water out of the right tank...but last week I got two tester tubes full of water before my precious autogas started stinking up the tube! I am going the Monarch route...for about $165 if I remember correctly. I'm tired of all that water, and it is a real pain in the winter as the water freezes and I can't open the quick drains at all until I put a hair dryer on them. Today I couldn't open the gascolator drain until I ran the engine long enough to get some heat down there. I've never had the gascolator freeze, but then I do see a lot of very small bullbles of entrained water each time I drain..and I guess these got together on me today!

djbaker, just noticed you are in MA. I'm based at Mansfield (1b9). If you are interested we could hook up and I could show you the Monarch shield installation on my '52. I'm very happy with them.

You can put Prist in the fuel to avoid freezing, but admittedly that's treating the symptom, and not the problem.
The bottom of the filler neck "well" should be sealed with Pro-Seal. That neck is threaded and screwed into the tank. Perhaps the sealant has dried and cracked. A good seal will not leak.

Doug Thank you I will contact you after this cold spell. I would like to see another 170 and ask a lot of questions. Our plane is a father son PROJECT almost back together.

djbaker, No problem! Shoot me an email or private message on this forum and we can work something out. Good luck with the project!

George, you mention Prist. I am wonder does this remove the moisture from the fuel. Problem is with my fuel, I see millions of little entrained "water bubblets" when I drain the fuel out of the gascolator. Don't see this at any other drain point. The little bubblets drift to the bottom, but I can continue to drain fuel and each sample from the gascolator has these bubblets. The engine does not seem to mind...the only problem being the freezing of the gascolator drain in cold WX.

One more question George. I see in the SRAM that some folks use or have used "GASDRY" in their fuel systems. I thought this stuff was pure alchohol and would be bad for our "old timey" systems where real rubber seals (2003?) are still used. If it is OK to use the "GASDRY" products from the auto parts store....I'd like to know as this may help with my water problem until the WX gets warm enough to put the Monarch shields on.

I have the Monarch fuel caps on my plane and like them very much. They were already on the plane when I got it so I don't know cost. With them you do not have to worry about rain water getting into your tanks.

Harold H

wa4jr wrote:George, you mention Prist. I am wonder does this remove the moisture from the fuel. Problem is with my fuel, I see millions of little entrained "water bubblets" when I drain the fuel out of the gascolator. Don't see this at any other drain point. The little bubblets drift to the bottom, but I can continue to drain fuel and each sample from the gascolator has these bubblets. The engine does not seem to mind...the only problem being the freezing of the gascolator drain in cold WX.

One more question George. I see in the SRAM that some folks use or have used "GASDRY" in their fuel systems. I thought this stuff was pure alchohol and would be bad for our "old timey" systems where real rubber seals (2003?) are still used. If it is OK to use the "GASDRY" products from the auto parts store....I'd like to know as this may help with my water problem until the WX gets warm enough to put the Monarch shields on.

Do not use any fuel "driers" type additives which are alcohol. Virtually all of them are,and will damage your fuel system. (They also absorb water and precipitate it back out at cooler temps. This will ruin your day when the engine loads up with water and quits.)

Prist will not absorb water. It will only prevent the water from freezing and blocking screens and plumbing.

Thanks George...just wanted to check. Perhaps we need to find these articles in the SRAM/170 Book that are in error and make sure they are omitted at the next printing. Don't know where I saw the mention of GASDRY use...the SRAM or the Classic 170 Book...but it is in there somewhere. Speaking of udating the SRAM...it really does need an overhaul although I still find it very useful. I find some of the articles are not valid any longer...and many parts sources are surely no longer in business...or phone numbers have changed..etc...

What would have been nice would've been to date the articles. When you read an article written by someone who did a Lycoming O-360 conversion and they comment that the $5K cost was kinda steep,you just know that it was written back in the 70's.
I have a 1st (& so far only?) edition copy of the SRAM Book (first offered for sale in 1998) and a 4th edition copy of The 170 Book (1996) and neither has the articles dated. Maybe this can be rectified in the future,maybe not. It'd be quite a job to go back thru & find the original submissions.Both books have articles from a long time back,judging by price info,etc.

Eric