Fuel leak
 

My 125 leaks a little bit of gas every once in a while. The glass bowl is wet and the gas drips onto the coil and then in the plywood floor of my shed. I thought that I fixed it last week when I removed and cleaned the glass bowl, made sure the O ring was seated properly and tightened it all up. It held for a while, but last night I could smell the gas from the shed when I was out in the yard with the dog. I closed the valve last night and I think the leak is stopped. Because the whole assembly was wet with gas it is hard to tell where it is coming from. It might be from where the sediment bowl threads into the tank. Maybe its the shut off valve, the gasket again? This is my only Cub and I've only had it for about 4 1/2 months so I haven't learned all the usual trouble spots yet. Is there one component more likely than the others to fail? I did have the tank, sediment bowl, fuel pipe. and carburetor off a few months ago. Should I have used some kind of sealer or tape on the threads when I put it back together? I know I would need to seal with something that the gas would not eat through.

The packing on the shutoff valve is probably shot. You can use two very small O-rings if you can find ones that are gas resistant. I have done that in the past, but I can't remember what size O-ring I used. I generally don't use any sort of sealer on the threads and I rarely get leaks. I have used teflon tape in the past, but I am not convinced that it's gas resistant. You can also try replacing the bowl gasket if you didn't do that when you had it apart. Get an OEM Kohler one, as the aftermarket ones swell a lot when exposed to gas.

I guess that I might find the O rings for the valve at a better hardware store. The gasket should be available through my local CC dealer right?

Yep, and you can use the parts lookup link in the tech library to find the part number, too.

Of course I will have to empty the tank before I can work on the valve. Hopefully it won't empty onto the shed floor before I have some time to mess with it.

Would I buy direct from Kohler or is that something I can get from a CC dealer?

These parts are good to have more of! Go to search and type "fuel trank repair" .....I know it is misspelled but you may want to check it out. One more thing,...DONT overtighten up the sediment bowl fixture to the tank nipple, you will crack the sodier seal that where the nipple itself is fixed to the tank. I dont believe this last time that I used any thread sealent, have no leaks here!

Teflon tape is resistant to oil & gas, no question, and does it's job well.
BUT
We quit using it, as it always to seem to find it's way into spools, valves or solenoids causing to many re dues/downtime.
I have used Teflon pipe sealant in a tube with good results.
But it is expensive, and has a awful odor

When I got home from last night at 10:30 I went out to the shed to check on things. It appears to be leaking at the tank nipple. Maybe when I had it all apart a couple months ago I loosened things up enough that all it took was the vibrations of some run time to crack it. Can I solder it with standard copper plumbing stuff or will I need it brazed? I have access to a full machine/metal shop and a bunch of very skilled guys at work if need be. I see that the newer Cubs have plastic tanks. Will one of those swap in for the original, and, are they an improvement over the metal?

Where do I find the parts site?

Cub Cadet parts sources
 

This is where you can find a "sticky" called Cub Cadet Online Parts Look up. I plan on ordering some of these parts myself soon to have on hand. I used regular soder and a torch. It was not hard to do at all, just that my soder job was not pretty, but has stopped the leak thus far. I'am gonna bring up "Fuel Trank Repair" by Fer 100 and comment so you can read what the other Members have said about this subject! Hope that helps more.

Normal solder will work just fine, wash out the tank well with hot & soap and water and re sweat the fitting into the tank.
Acid or rosin core solder works well or soldering paste. You want it
re sweated not "mudded" I prefer to use a big old soldering copper,
not a propane torch. But if it is clean a torch will work ok.
The key here is CLEAN and use acid or paste. I would not braze it. Brazing is too hot, even silver solder is a little too hot.
I guess plastic tanks are ok, but I prefer old school galvanized steel.
They went to plastic because it is rust free, & less expensive to manufacture.

Thanks. I'll look around for it.

Flatbedford,

If this ever happens again and you want to trace the leak, you might try either adding some Marvel Mystery Oil to your fuel or Sta-Bil--both are actually good to use as a fuel additive (read proportions on labels) and they will tint the fuel a redish color to help you trace the leaky area. I've done this before with good results and I hope that you never need it, but just in case....

Cub Cadet 123

Thanks for the advice. The shop foreman at work set me up with some silver solder and correct flux. He says that he repairs motorcycle tanks the same way. I just have to make sure I don't blow myself up with the fumes. He says rinse thoroughly with soap and water first.

I already had that site bookmarked. I didn't realize it was that one. I have used it a few times. Thanks anyway.

I would be more worried with trying to silver solder where there has been regular or soft solder,as there is quite a difference in melting temperature.
I wouldn't do it, I would use regular solder.
Silver solder is right up there with brazing rod as far as melting temp.
Maybe I should say that has been my experience, or possibly he gave you a special silver solder.

Too much heat
 

It was mentioned that I be carefull not to heat out the soider out from under the nipple plate , BTW. .

The guy who set me up with the stuff thought that it was silver solder when he looked at the tank. That's why he suggested it. Do we know for sure what Kohler used? He also said that as long as I clean it thoroughly and apply the flux all around the silver solder will find its way and close up the gap. I'll have to do some research on silver solder before I do anything.

Alot of folks call lead free solder "silver solder" improperly. its melting temp is not much more than 50/50 very feasible with propane. Plus its much stronger Than 50/50.

Silver solder wont melt with propane. you need at least methylated acetylene (MAPP) or oxy-acetylene. Silver solder is very stiff in rod form hard to bend. Lead free solder is bendable and usually on a roll.

I spent some time on the tank last night. First I poured a couple tablespoons of Simple Green and water into the tank. I put the cap on, plugged the threaded nipple with my finger and shook it for a while. With the garden hose I filled the tank until it overflowed and then let it drain a couple times. When it was full of water I plugged the bottom hole with my finger and watched for leakage. There were a few leaks right where the threaded tube is attached to the flange that is soldered to the tank.
I drained the water and blew air through the tank with the exhaust from my shop vac. After that I piped some exhaust from my '70 F350 (the dirtiest exhaust in the driveway for sure) into the tank. After all that I figured I could work on the tank without much fear of explosion.
With a wire wheel on my Dremel tool I cleaned the area thoroughly. I smeared flux around all the suspect joints and went at it with MAPP torch. I was surprised how much heat I needed to work the silver solder, but I was able to lay a nice bead around the suspect area.
After some cooling time, I chipped the flux off and did some clean up with the Dremel tool again. I filled the tank with some water, plugged the hole with my finger and watched. No leak. After shaking as much water out as I could, I threaded the valve/glass bowl assembly back onto the tank and closed the valve. I put about a cup of gas in the tank and checked for leakage. Still holding. I dumped the water gas mix and refilled the tank with some more gas.
I left it out side over night and there is still no leakage. I guess I have fixed the tank. I still have to get some paint on the tank where the torch burned it off and I will be replacing the valve/glass bowl assembly before I put it back on the tractor.
Looks like I have fixed my leak with minimal expense and without any explosive gas fume mishaps. Thanks to all for your input.

talking of silver solder, my dad worked at westinghouse for 40+ years in the copper shop and over time some of the extra silver solder found its way home here.:biggrin2.gif:

there are 2 main types that i have on hand the first comes in a round rod form and when heated it tends to flow and fill gaps and the second is a squared rod type that you can bild up and fill in with. also have a limited amount of a third version that is a thin paper like wafer, he said when you had 2 large flat surfaces you would lay this between thme and heat it up and when done was welded fully on the inside

No leak/soider
 

Here is a pict., I guess I did use white tape....no leaks yet.:High5: I forget what soider I used, but it sealed it's own soider weld mud-job. Used regular torch in hand-held bottel. One important factor to preventing a fuel leak as my IH 71 is to make sure the tank is strapped properly and that the saddel cussion is square, and not to over tighten. I used lamp oil wick from a hurricane lamp. Dont over tighten to tannk nipple.