Seat tank leak

[joeheli]

I have a big problem. I got a seat tank that the gas feeding was rusted, so I change the feeding to a new brass one . I use the first time that leak teflon to seal it.But it start to leak. So I use this time JB weld. I test it to see if it was more leaks, so I see that everything is alright (Cool..No leaks! ).

So last Saturday I start the engine ,taxi, Oh!... by the way I did my first hops solo that day. Yea! :D . When I finish for the day, I see a leak again on the fitting. My instructor told me that the leak is because the seat tank is plastic and the feeding is brass. The seat tank (plastic) expand and contract because of the fuel gases and heat, but the brass dosen't. so when it expand it start leaking and that I have to get a plastic feeding. The one that use to be on the tank was not the original.

What do you guy recommend me?.

[GyroRon]

A new rubber grommet and stay with the brass

[joeheli]

Yes Ron I know,but I can't find it anyway the brass feeding you have to screw it on the plastic.

[GyroRon]

just order a new rubber piece and brass piece as a matched set from Brock and life will be good again. These parts can't cost more than a few bucks. Don't go postal on me!

[joeheli]

Ron they made a new bigger hole. The brock ones don't fit on the new hole.

[GyroRon]

Well then sorry I just don't know what to tell you. I guess you will have to take a measurment and get a larger new rubber piece and the proper size barb.

[Chuck Irby]

Jose, measure the diameter of the hole and let us know. Then maybe someone can offer a good suggestion.

[Chuck Roberg]

Here's from Norm's forum. Used to fill and stop leaks in plastic tanks used with fuel and to hold fittings into plastic tanks.

Date: February 26, 2002 07:49 PM
Author: louis sippell (louis@lsippell.com)
Subject: bonding
3M structural panel bonding adhesive part # 08115
Two part epoxy used to bond steel, aluminum, SMC, and FRP (traditional fiberglass).
(You don't need the dispensing gun to use it)
Louis

[joeheli]

Thanks! I will try to see if I can get it.

[rehler]

Jose,

Over the uears I have worked with many Ken Brock seat tanks and have a stack of brass screw-in fittings in a box as a result. I suggest you drill out the hole in the seat with a 1/2" drill bit and install the rubber grommet and plug-in fittings sold by LEAF, CPS, etc. http://mikes.automated-shops.com/cgi-bin/webc.cgi/st_main.html?p_catid=118

That will solve your problem.

However, the thickness of the seat tank wall varies. If your hole is at a thick part of the seat (more than 1/4" thick) then you also need to cut away some of the inside rim of the hole to allow the rubber grommet to expand bigger than the hole on the inside of the tank to hold it in place. Otherwise it will pull or fall out.

I also recommend the same to plug unused holes. Install the rubber grommet in the 1/2" hole and insert a short 3/8" bolt. That will plug the hole. Even better is a 3/8" diameter piece of aluminum - file some rings around the aluminum to let the rubber stretch into them to better hold the plug in place.

[joeheli]

Thank you Ken, Does are the one that I was tryin to get. The old tank use to have does rubber grommet and the fittings, but the fitting was rusted so I took it out and the rubber grommet was old and broke. I try to find does but I din't find it . Thank's to you now I know were to find it. Thank you again! Ken: Which one from the link you post do you recommend me to use?

[Chuck Irby]

Jose, If you call Aircraft Spruce, the only parts you should need are part numbers FTEB01 and FTBO1

PS, CPS on line has the same parts. Their numbers are 7032 and 7030

Jose, I would not get the valve. I have owned several and none of them worked properly for very long. The plain open elbow is what I am using now. I can depend on it.

[joeheli]

Thank you Chuck I will get it.

[Chuck Irby]

Jose, you can install the rubber bushing a lot easier if you soak it in hot water for a couple of minutes before you insert it into the tank. Make sure the hole is the right size, round, that the edge is smooth, and that the tank is cleaned out good ahead of time. Then once the rubber bushing is installed the fitting can be pushed in immediately, while the rubber is still warm. This procedure has worked best for me.

[joeheli]

Thank's Chuck . I will try that :D !