My NH has been a great carb after performing a full rebuild about 4 years ago. Recently it started leaking badly with no warning. Checking the parts revealed a rather well worn needle inlet valve. Resurfacing it and seating it solved the issue.
Here is what I believe caused the accelerated wear. We drove with Lizzy on a trailer across country for a total of about 7 or 8 days of driving. The carb didn't leak before, but did after. I wonder if the gas in the bowl jostled around the float and hammered the needle valve seat area while being trailered?
Anyone else seen this?
Interesting. My first thought was what's the difference between it being trailered and it being driven? But when it is being driven, the needle stays seated pretty deeply, but on the trailer, once a little gas seeped/vibrated/evaporated out, it never seats again (Assuming the gas was shut off at the tank or carb), leaving it free to vibrate continuously. I don't know if that's what happened or not, but it's a theory.
Drove her to work and was in a meeting when there was an overhead page for the owner of a model T Ford to call security please. I got out there to find a bucket had been placed under Lizzy, catching the rather rapid dripping. Good thing I hadn't parked any closer to the smoking shelter..........
The carb started out full but was shut off at the tank. Hot temps plus the 55 MPH wind must have let some evaporate. The tires were tied down but she could still bounce on her springs as well as the trailer springs. That makes a lot of float pounding on that needle seat.
Everyone knows at work who that page was for and security had no problem finding the owner of the model T. For several days people who heard it asked me about it. Everyone remembers it after they see you drive a model T. I guess I am the only T driver out of about 3,000 employees. I gotta be sure Lizzy behaves or we may get a reputation.
If you have a drain on the carb, maybe shutting the fuel off at the tank and draining the carb bowl would let the needle fall down completely and not contacting/wearing the seat while being trailered.
..and driving a leaking vehicle to work, been there, done that :S
Bought a pickup converted '71 Volvo 164 some 20 years ago and as always, it didn't have much gas in it. Filled it up when I got home and went to work the day after, everything seemed fine. Suddenly there was a big commotion at the parking lot, the fire brigade was all around my car putting some absorbent material on the asphalt - the parking was on an incline and the tank had a rust hole on the top unbeknownst to me, letting out about a gallon on the pavement. The change of ownership hadn't gone through yet, so I bet they were curious why some non-employee living 50 miles away had parked at the company parking lot..
You beat me to it on the carb draining idea. If it really was the trailering, that should fix the problem.
Your idea might be true. However when you drive over rough roads the float will also bounce. I like the idea of turning off the gas and draining the carb. You can also achieve this by running the engine after the gas is shut off until it stops from no gas.
Model T's are notorious for leaking with no advance notice, so it is a good idea to shut off the gas every time the car is parked. At least look under before you leave the car to see if it is running out.