Carb Leakage

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Model T Ford Forum: Forum 2016: Carb Leakage
Top of pagePrevious messageNext messageBottom of page Link to this message  By Daniel E. Snell on Monday, February 22, 2016 - 03:29 pm:

Can someone give me an idea of what would cause a newly rebuilt (by Langs) carb to leak out the back or Choke end? I found to my disappointment a large puddle of gas on the floor this morning after installing the carb yesterday and driving it around for ten miles without any apparent issue,


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Gresh on Monday, February 22, 2016 - 03:34 pm:

One thing that will cause a new carburetor to leak is gas with sediment in it. The needle may not seat properly if there is sediment coming in with the gas.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Monday, February 22, 2016 - 03:50 pm:

Daniel - This does not answer your question, however, in the interest of safety, I'd add something to the point that Larry just made:

Your profile indicates that you may be fairly new to the Model T hobby and if so, you probably already know this, but whatever the case, for what it's worth,.....

All Model T's were equipped with a gasoline shut off valve. One big reason for this was because of the problem that Larry just mentioned, however there are several reasons/situations that could cause a real hazard with a gravity feed fuel system like on the Model T. We are all used to modern vehicles, whereby when we park the vehicle and shut off the engine, no more fuel is pumped out of the fuel tank. For that reason, we all give no thought at all to any sort of fuel leak hazard. Of course, with gravity feed like the Model T, just a speck of sediment preventing the carburetor needle valve from seating can allow an entire tank of gasoline to leak out of the tank just overnight. Especially dangerous with a vehicle stored indoors, and ESPECIALLY where there is a source of ignition like a water heater pilot light, furnace, or anything electrical causing a spark.

Again, not to be "insulting", but it is easy for any of us in our modern, everyday hustle & bustle and busy society to forget about such a hazard. End of "rant",....sorry, but I guess I have a "thing" about safety,......harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, February 22, 2016 - 04:55 pm:

The one Bud Scudder got from Langs had a Grose jet in it and did the same thing. I swapped out the Grose Jet for an original needle and seat on Bud's back porch. Problem solved.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Daniel E. Snell on Monday, February 22, 2016 - 05:58 pm:

Actually Harold, I have been messing around with Model Ts since 1977 and I should know better I suppose, but the purest blood in me won't let me change her up to much, Royce, I used to have more trouble with the needle and seat and went to the Grose Jet, but Steve at Langs just told me that the Grose jet has a narrower passage so they have now a more improved needle and seat part number 6212OR which I plan to try.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Monday, February 22, 2016 - 07:18 pm:

One of the best things you can add is a shut off valve at the carb and use it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Peter Claverie, Memphis TN on Monday, February 22, 2016 - 07:19 pm:

This doesn't apply to Daniel's original question, but I found out the hard way that you MUST turn off the fuel, and it's better if you run most or all of the fuel out of the carburetor, when you load the car onto a trailer.

The bouncing of the trailer, and therefore bouncing of the float, will empty a fuel tank on a long trip. And, especially in an enclosed trailer, you've got a real hazard, not to mention the lingering stink!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Monday, February 22, 2016 - 07:35 pm:

Ah some of use like the stink of gasoline better then roses and it doesn't seem to upset our hay fever. :-) LOL

Peter, very good point.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Monday, February 22, 2016 - 10:52 pm:

Unless they have improved the quality of the needles used in the reproduction needle and seat sets, every one of them needs to be reground to the correct finish and angle to seat correctly.

The last ones I got were absolutely TERRIBLE!!

This tip wouldn't hold molasses in February in Montana let alone the new ethanol laced gasoline we are all using.



I recently bought another small lathe so I can set up to regrind needles without having to do a set up each time to get the angles right. Sorry, I won't be doing them for anybody else, I just don't have time.

I make quite a few needles from scratch and have been grinding the tips on my valve grinder. I think this will work better if I ever get time to get it set up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Mikeska, Denver CO on Monday, February 22, 2016 - 11:18 pm:

Stan,

FWIIW I have a hard time believing that any of the good family owned T vendors sell that crap! IMHO they should be called out, by name, if they are selling parts that are that so obviously defective.

My take on this is that if you are new to Model T's you need to know that most carb equipped cars have fuel pumps. When the car is not running there is no fuel pressure on the needle and seat. A model T has no pump and the fuel is gravity fed to the carb. Every running T should have a valve in the fuel line to shut off the flow to the carb and you should turn it off every time you shut the motor off unless you are comfortable with raw gas leaking out from under the car!

(Message edited by paulmikeska on February 22, 2016)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Monday, February 22, 2016 - 11:30 pm:

Yup!! Good advice. A cat hair will hold a gravity feed needle open enough to leak. One drop a minute is a quart in six hours.

I have those needles from at least two different vendors, they look exactly like that. It is fair to say that I have not bought any for a year or so. The last order was for a dozen at about $13 each so I spent $140 for sets I had to work on in order to use them.

This is what was supplied for Holley NH's. The ones for the Holley G was just as bad if not worse.



I hope they have corrected the problem by now. I doubt it but I hope they have.

There is no excuse for this. There are still millions of carbureted engines running in the US with kits available for virtually every one. A $15 kit for a Carter WO on a 46-48 Willys CJ2A has a needle and seat that does not leak against 2.5 lbs of fuel pump pressure. Don't tell me they CAN'T make them so they work. They don't want to spend the effort.

I am making my own for NH's.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Monday, February 22, 2016 - 11:34 pm:

Since I am on a rant! QUIT using that plastic tape on fittings. It is not necessary. Buy a tap for 1/8 pipe threads, chase the threads and screw a brass fitting in to it. If the threads are good it will not leak. 90% of what I find in seat sets that leak is little pieces of teflon tape.

Also: Put a shutoff in the line!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Mikeska, Denver CO on Monday, February 22, 2016 - 11:42 pm:

Yes! Good tapered pipe threads do not need any kind of sealant on them. That is why they are tapered.

(Message edited by paulmikeska on February 22, 2016)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Mikeska, Denver CO on Monday, February 22, 2016 - 11:44 pm:

He He... Why do you think it is called pipe DOPE?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Coiro on Tuesday, February 23, 2016 - 12:05 am:

I suppose it's possible that some sediment in the fuel is causing this problem. _Dismount the carburetor, open the fuel valve and drain a few cups of fuel through the carburetor fuel line into a big, very clean glass jar. _Cap it and let it sit over night to see whether any crud settles to the bottom. _If there's no obvious contaminant, pour the jar through a coffee filter into another jar and see if the filter paper catches anything. _If it's clean, you can pretty much forget sediment as being the problem. _Having done that, if the carburetor is newly rebuilt by Lang's and the thing is leaking fuel, you need to phone Don and let him know. _He's a great guy; the type who won't let a customer go unsatisfied.

And Stan is 100% right: If you don't have a carburetor shut-off valve, you need to install one.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Tuesday, February 23, 2016 - 01:26 am:

If you worked in many steam shops and a roll of Teflon tape were found in your tool box, you'd be walking out the door. Why? Because if any of the Teflon finds its way into the pipe itself, it will string out and foul valves and block small passages.
If you really need a little dope, Rector Seal is a better choice. I have been known to put a dab--A DAB, I say-- of anti seize on adjusting needle threads.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Tuesday, February 23, 2016 - 01:35 am:

My post is the 3rd one down in this thread where I thought I provided a good safety tip regarding the use of a fuel system shut-off valve, but I must have said something wrong, because a half dozen other guys have said the same thing.

Actually, I "DID" say something wrong, as I was thinking of my Model A, which has a fuel shut off valve inside the car, under the cowl tank. Very convenient. Most Model T's however have only the shut-off valve on the "potato", under the gasoline tank, which except on the "improved" '26 & '27 Model T's which have a cowl tank. Very inconvenient to crawl under the car to the shut-off valve, and, if it does in fact have one, it's usually stuck from many, many years of disuse.

So, at any rate, I think we've pretty well covered the need for installing and using a shut-off valve in the fuel line somewhere near the carburetor.

In my opinion, the one that's commonly sold by T parts suppliers that has the shut off valve built into the 90 deg. elbow that attaches the carb end of the gas line to the carburetor is not a good choice. I prefer a regular plain 90 deg. elbow there, and an inline shut-off valve just before the elbow. That makes it a simple matter to close the shut-off valve when necessary to remove or change out the carburetor and then disconnect the line between the closed valve and the elbow. FWIW,....harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Jensen on Tuesday, February 23, 2016 - 07:56 am:

I have been thinking about ordering a needle and seat with the neoprene tip for the NH carburetor (Lang's #6212). Do they work better than the stainless needle? Seems like it runs a little rich if it has been shut off for a short time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Tuesday, February 23, 2016 - 09:18 am:

I had trouble with a neoprene tip sticking, so I put in an original needle.


I believe the third needle here is the original type used in the NH. You may need to do some repair on it as Stan described.

Interesting that the packaging label Stan showed says "Original". But the original has a steel tip.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Jensen on Tuesday, February 23, 2016 - 03:35 pm:

Thanks for the advice on the neoprene needles Steve. I do have the new replacement from Lang's in it now. It will seep gas out of the bowl gasket if I forget to shut off the fuel. I put a new sediment bulb on the tank, and have the shutoff valve that replaces the elbow. I turn them both off if the car is going to be sitting for a while. The one on the carb is a lot easier if you are just stopping for a short time.
I have a Ford 8N that I put a kit in the carburetor about 15 years ago. That kit came with a neoprene tipped needle, and does not leak when sitting. It even likes a real quick pull on the choke no matter how hot the engine is.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Gelfer on Tuesday, February 23, 2016 - 03:52 pm:

I tried the neoprene needle and it worked fine for maybe 2 seasons,then started to leak. Put in a new metal one and seat, and have not had trouble since.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Tuesday, February 23, 2016 - 04:09 pm:

I have used the neoprene tip needle and seats in the NH also with mixed results. No issues using the original style. Sure you might have to spend 45 seconds polishing the needle - no big deal.

See here how to repair:
http://www.mtfca.com/discus/messages/411944/469501.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By Daniel E. Snell on Wednesday, February 24, 2016 - 09:06 pm:

Royce, thank you for those photos and step by step process. This is a big help for me in understanding why I have periodic gas leakages. Next time, I know what to do and will use the original needle in lieu of the grose jet.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Corey Walker, Brownsboro TX on Wednesday, February 24, 2016 - 09:35 pm:

Every time I kill my T I look to check for drips. Most of the time it is alright but today I had gas dripping from a Holley G. It is an original needle and seat. Probably just a small piece of trash. I just cleaned the tank on my 14, it has a 4 ball Kingston with a grose jet and I don't trust it either because I'm sure it still has some stuff in the tank still. I've never had a neoprene tipped needle in a T but did on a brand new Edelbrock I put on my truck a few years ago and nothing I could do stopped it from flooding over except putting in new needles and seats (I think it had 2).


Top of pagePrevious messageNext messageBottom of page Link to this message  By R. S. Cruickshank on Thursday, February 25, 2016 - 04:48 am:

Shut off valves that are available from most dealers have not been satisfactory for me. I have used several brass valves that work for several months but gradually get too tight to move by hand and require you to keep a set of small water pump pliers on the floor board. Instead, I have found that there are mini BALL valves that work easy all the time. Not too original but my cars are drivers and in the end if I can "work them, I'll use them".


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tim Wrenn-Monroeville OH on Thursday, February 25, 2016 - 08:47 am:

I'll play the devils advocate here, by saying that don't all the T's basically have a shut-off valve? As in the sediment bulb under the tank? Trouble is of course, we're all gettin too old and rickety to crawl under and shut it off after every long exhausting trip!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Corey Walker, Brownsboro TX on Thursday, February 25, 2016 - 09:33 pm:

I lift up the front floorboard and turn the gas off. Screw in the sediment bulb so that the handle is in front.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker, Ramona, CA on Thursday, February 25, 2016 - 10:54 pm:

On the Coupe I have cheated... I installed an electric (6 volt) fuel shut off....... I got tired of lifting the hood, finding pliers and all that none sense after I installed the Stomberg OF and Stan recommended a shut off. It draws 1/2 amp so should not cause any problems but I wonder how long it will last.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Daniel E. Snell on Thursday, March 10, 2016 - 02:04 pm:

Any of you guys suggest the use of an in-line fuel filter? Maybe that is all that is needed.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Thursday, March 10, 2016 - 02:04 pm:

No, that will cause more problems.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Thursday, March 10, 2016 - 06:06 pm:

Daniel, if you install a filter it will cause problems. Just make sure the screen in the sediment bowl is intact and everything should be good.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chad Marchees _____Tax Capital, NY on Thursday, March 10, 2016 - 06:44 pm:

Well, maybe I am in the minority, but inline fuel filters have worked fine for me. (I use Napa 3032). All my fuel lines are 5/16 size too. I haven't noticed any loss by using the filter. I agree that the Sediment bowl is probably best, but I got tied of fuel leaks from it/them.

To each their own, but it works for me.


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