Leaky Zenith carb.

To have a pool of fuel on the floor, obviously both valves are leaking.
To remove the valve under the tank, drain out the fuel first, undo the line to the firewall and then the valve. Have a rag handy to catch the few drops that will come out. I again suggest you use the repair kit I gave a link to earlier - they are great. While I was in there, I'd make sure the pencil filter is in place before reassembling. Fixing that valve might stop the carburetor leaking but only because no fuel will be getting to the float valve when the tank valve is turned off. Test the float valve by leaving the fuel turned on at the tank and look for a leak. I'd replace the float valve anyway while I am at it.
 
Correct me if I'm wrong but I don't see how that repair kit for the shut off valve will help with a leak through the gas line. That packing is to stop gas from leaking out around the handle on the valve. To repair the valve so it stops gas going through it you need to lap the valve cone usually done with very fine compound or tooth paste.
 
There must be a club near Hershey you could get some help from if you don't feel confident on taking the carb apart. I live about 1 1/2 hours from Hershey and would be glad to help if you brought it down.
 
WMWS, I just ordered the repair kit for the shut off valve and now that I think of it maybe I should have just ordered a new valve. I do not want gas all over the floor of my car when I take off the valve. Is there any best way to drain the tank? I will probably change the valve plus replace the float valve in the carb. Wish me luck, I never did this before.This car looksi like new and I wasn't counting on all this at once. Jim
 
Jim -
If the on/off valve is shiny brass and leaks, it's probably one of the poor reproductions from a few years ago. They looked nice, but they would leak fairly soon. The bad news is that these valves cannot be repaired with the rebuild kits. They are "tossers". The new on/off valves in the past 10 years or so are much better and will not leak. If you have an original on/off valve, however, it would be worth your while to try and save it with the kit. If nothing else, you'll gain some valuable experience. Should the rebuild not work, THEN you could order a new valve. Of course, only put a minimum amount of gas in the tank to check for leakage over a couple days' time!
Marshall
 
When I drain my tank I disconnect the line at the carb and loosen the other end at the firewall. Then rotate the line away from the carb. Get a hose of the correct size so it is a tight fit and slip it over the end of the gas line. Put the other end in a gas can and turn the gas valve on. Most of the gas will come out but not all so when you do unscrew the valve have a small container of some sort to catch the last bit. If you have floor mat rugs in your car you may want to take them out as if you do spill some gas on the rug you will be smelling it for a long time. I think new gas valves are about 35 dollars. Trying to repair one is a tedious process and not always successful.
 
Marshall, My car was restored in 2009 and only has 3,000 mi. on since. So I don't know if the valve is a bad one or not but it must be for lasting only that long. I'm going to go broke ordering all these kits from Snyder's with the shipping costs twice or more than what the parts cost. Jim
 
You may be better off to just order a rebuilt carb from Bert's rather then try to repair the one you have. Then check out your shut off valve. I have a leaky valve on my huckster. So I purchased a line from the old valve to the firewall and in this line is a new valve. I think most of the vendors sell these items. This saves you having to drain your tank of gas.

Like mentioned, I have had hair line cracks in the body of the carb which caused a leaks. Also have had the threads stripped in the bottom carb part where the main jet screws into the bottom carb part. This causes gas to leak out into where the choke is and then drip off the bottom bolt. So like I mentioned above, you may be better off the buy a rebuilt carb from Bert's or one of the other vendors.
 
wmws said:
Correct me if I'm wrong but I don't see how that repair kit for the shut off valve will help with a leak through the gas line. That packing is to stop gas from leaking out around the handle on the valve. To repair the valve so it stops gas going through it you need to lap the valve cone usually done with very fine compound or tooth paste.
Click to expand...

The repair kit comes with new packing and a special fuel proof grease which is applied to the taper of the valve. It seals up the tiny scratches that allow the fuel to leak without lapping anything. Take my word for it, IT WORKS. The valve works smooth and easy afterwards with no leaks.
PS, the grease is in a small capsule that looks like one that might contain medication. DON"T swallow it if you ever want to leak again!!!:D:D
 
Synchro 909, I hear ya! I do have the carb off now but I still have my gas line hooked up and it is dripping a drop of gas about every 3 or 4 seconds in to a pan. Won't the repacking kit only help for if the shut off valve inside the car is leaking? I took a video of the car and the leaking with my cell phone but I don't know how to post it on here. Jim
 
skeazle said:
Synchro 909, I hear ya! I do have the carb off now but I still have my gas line hooked up and it is dripping a drop of gas about every 3 or 4 seconds in to a pan. Won't the repacking kit only help for if the shut off valve inside the car is leaking? I took a video of the car and the leaking with my cell phone but I don't know how to post it on here. Jim
Click to expand...

Jim, For the carb to be leaking when the fuel is turned off, both the valve under the tank AND the float valve must be leaking. If you were to fix one properly and turn off the fuel EVERY time you leave the car, you will have no leaks but that is only a half arsed way to do it IMO. Neither should leak.
 
At a Hardware or Plumbing supply, you can get a NEEDLE type valve, that fits PERFECTLY in place of the ORIGINAL valve, for about $4.99. I've used them in BOTH my cars. DO use the "pencil" filter, in the TOP of it!!!
Bill Plumber
 
Synchro909. I will give the special fuel proof grease a try. I have an original valve that I would like to be able to use.
 
I think I am going to put a viton float valve in the carb and replace the two paper gaskets and put it back on and open the valve up and see if it still leaks. If it does then I'll replace the shut off valve. Maybe I'll get lucky. Thanks everyone for all your help. Jim
 
I would not trust just the float valve to stop the gas. Henry put a shutoff valve on the car for a reason. If a tiny speck of dirt or rust gets in that float valve you will have a puddle of gas on your garage floor again.
 
Hi Guys, Well I finally got to put the new float valve in my Zenith carb and replaced the big gasket but the smaller red washers I let go cause they looked good not mashed. Then I took out the shut off valve in the car and it was a piece of cake no leaks. I was expecting the worse but that is how I am working on 87 yr. old stuff. I opened up the shut off valve and presto the carb started leaking. So I took it off (2 min. job) now that I have it down pat. Well, I noticed that I should have replaced the red washers with new ones while I had the carb apart so I did that and it was good to go then. One thing I wasn't sure of when I took out the old float valve was that it had two red washers on the threads and I was not sure if it had to be that way. Maybe the extra washer acted like a shim. I put it back together with just one washer and put it back on the car and no leaks anywhere but it took a while till I finally got it started. Is that normal? Maybe it just took a little time for the gas to fill up the empty carb? I was about to give up and put a "For Sale" sign on it. I'll go out and try starting it in the morning to see if it starts better. I want to thank everyone who took the time to answer all my questions or give me their advice. The more I do with this car the more of an education I get. Jim
 
Putting a second washer under the valve is the standard way of adjusting the float level and is probably why it was there. Putting only one back might now mean your level is high. If the engine dies when you brake to a stop, that's where to look. Do a search here - there is plenty of info on setting the level and it is well described in Les Andrews' red book.
 
here's my list (notice that a poor gasket between upper and lower bodies isn't on it as it doesn't cause carb leaking per se)
Zeniths: Causes of leaking
Problem: Remedy
1 Leaking/loose float valve gasket: Tighten/reseal/replace
2 Leaking float valve: (or crud stopping it sealing) Replace ( or clean up if possible )
3 Friction on float hinge: Loosen
4 Incorrectly set fuel level: Re-set
5 Hole in float: Repair or replace
6 Too many gaskest on main jet Check
7 Cap jet or main jet too short: Replace
8 Leaking/loose gasket at main jet: Tighten/reseal/ replace
9 Leaking /loose gasket at cap jet: Tighten/replace
10 Leaking or loose GAV housing threads: Tighten/ reseal/ replace
11 Leak at fuel inlet union: Tighten/reseal/replace
12 Loose/leaking gasket at strainer: Tighten/reseal/replace
13 Loose/leaking gasket at drain plug: Tighten/reseal/replace
14 Cracked housing/leaking passage plugs: Repair or replace

1-7 will generally manifest as poor running.
8-14 will generally not affect running unless there is excessive leaking.
 
Good list. I also found a striped thread on the cap jet or anyway it was the one that screws in from the bottom.t
 
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