Leaking Zenith float valves

Brian T

Brian T

Well-known member
I have a question regarding leaking Zenith float valves, I just purchased a new float and needle and seat ( Viton tip ) and I am still having problems maintaining the 5/8 level in the float chamber.
I am using a glass to observe the test, the float will stop at the correct level for the most part but will continue to rise very slowly, sometimes rapidly, I added an another washer so the float is now set a little lower than normal hoping this would add additional pressure.
I can hold the float gently and it does not dribble fuel, the fuel is clean just a little fine sediment in the bowl.
I have another needle and seat being shipped, it is my understanding that this Viton valve can be taken apart and may have some brass remnants that need to be removed, has anybody had to do this.
Brian.
 
Make sure your float is not higher on one side or the other (twisted)
Also take the needle and put some Toothpaste on it and Lap it into the seat.
Ive seen some folks Strike the needle into the seat to make it "set". I lap mine.
Wick
 
I seat the needle with a couple of lite taps with a hammer,BUT i use steel needlesnot rubber tipped .Use a steel one if you can find one. This procedure does not work on rubber tipped needles.ken ct.
 
When I rebuilt my Zenith I put a new valve in it, but it leaked. That's when I found the top of the float had a dimple in it that prevented it from making good contact with the end of the needle. I had to fill in the dimple with a blob of solder.
 
with the viton needle do not strike it or lap it in thats the procedure for the all brass one. wherever you set your float height a proper functioning needle and seat will shut off the fuel. if your fuel continues to rise you either have a float problem or junk getting into the seat. i use the viton tips with great success been 3 years now on 3 different cars and they never miss a beat even if i leave on my fuel shutoff accidentally. i was told that the ethanol will eventually eat the rubber of the needle but am still waiting.
 
There are several styles of viton tip float valves on the market. The viton tip float valves I use come from Bratton's and they can easily be taken apart and cleaned. A few years ago when Walt started carrying them I discovered they were full of brass chips and would cause leakage. I brought it to Walt's attention and he so advised his supplier. However, Walt is still at the mercy of his supplier, and even though the situation certainly improved. I still take them apart before I use them, and occasionally I find a small amount of brass in them. They are easy enough to clean, so that is what I do.

Quite often you will find that a float will not work with the best of valves. The reason is they have been tweeked and molested by someone trying to adjust the float level. If the float does not come up straight it will not actuate the float valve correctly. You should never try to make adjustments to the float if you want it to work correctly.

Go to www.ocmafc.org, Tech articles, Tom Endy's articles. There is a lengthy article about Zenith carburetor restoration with photos. It shows the float level being set on a test stand.

Tom Endy
 
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myself I prefer the original needle,the dimple as stated can sure be an issue I had a side bowl that would do its little trick and try and empty tank,I finally put new float and original needle no more leaks now also have the electric shut off just in case
 
I, too, have used the viton tip valves for years and not had a problem. You can not put any pressure on them while fitting them or adjusting the float level because the tip can be damaged. They will stop fuel flow with just the slightest pressure up (especially on an A with no fuel pump pressure). It sounds like your float is not pressing straight up on the needle portion of the valve, so it is not seating properly.
 
Thank you to all who responded , I do have a question for Tom Endy , who I will firstly thank for the Tech articles that he has written and I have used many times---Thank You Tom.
I have attached a picture of the Viton float valve from Brattons which is identical to the one I have from Snyders, when you take them apart does the square end unscrew from the upper body?.
With the new float and new seat there doesnt seem like much else to cause this problem, I will look closely at the hinge pin bracket for excess wear, it seems odd that I am having the same problem as with the old parts, ( now you see me now you dont)
Thanks again.
 

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Brian T:

The float valve does not unscrew. Use a very small screwdriver such as you would tighten the screws in eye glasses. Put it through the four holes and pry out the teflon washer. The valve itself can then be removed. Use a magnafying glass and examine the end of the valve. You may find bits of brass inbedded in the rubber tip. Clean them off with your fingernail. Examine the interior of the valve where the seat is. Clean out any brass chips you see.

To reassemble press the teflon washer back into place with the same screwdriver. Make sure it is even. It is somewhat tricky, but with patience it can be done.

Tom Endy
 
Sparky said:
When I rebuilt my Zenith I put a new valve in it, but it leaked. That's when I found the top of the float had a dimple in it that prevented it from making good contact with the end of the needle. I had to fill in the dimple with a blob of solder.
Click to expand...

Agree with Sparky....check your float. The mating surface on the float where the needle touches s/b flat. A depression or ridge may limit proper movement.

Good Day!
Dave in MN
 
Last summer (2009) I made a test fixture for float valves as I was having 'issues' 18 Brand New valves out of 20 leaked. I had gotten them from various suppliers. FWIW
 
Just a followup and solution to my on going fuel level problem with a new float and valve, --- I made up an external level gauge so that I could see if the level would rise when the bowl was full at 5/8, no rise in level for several hours with the fuel valve on.
My problem ONLY occured when the bowl was empty, the level would rise to the 5/8 and stop, but then would continue to slowly rise up, I replaced the float hanger and pin as per advise here, which were badly worn, but the problem persisted.
Checking the float valve again some roughness could be felt at the very tip where the valve contacts the float, I took some metal polish, (Brasso) and buffed the tip to a fine finish, and also the top of the float where it contacts, ----- problem solved, I have tested it 10-12 times now with no problem.
Thanks again for your inputs, Brian T.
 

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