The Stovebolt Site Forums The Shop Area Engine Shop sealer for carb inlet fitting

I have 1954 3/4 ton with Rochester. The inlet fitting leaks fuel at the seal where a copper or fiber washer goes. The opening is not perfectly smooth or at a right angle with the fitting. What type of sealer should I use? It is not even a drip. I was thinking Blue Locktite. I've tried both fiber and copper washers.
Thanks
Sharon

I don't think there should be a fitting with a washer on a 1954 original Rochester setup. Can you post a photo?

Thread tape ??

The carb threads are 1/2 inch not pipe threads. PO had tapped out carb to 1/2 inch. Truckernix I think the original setup was pipe threads. Dusty I tried tape with no help. Carb King mentioned a sealer and I thought it was blue locktite.
Sharon

Blue Loctite is not a sealer, it's a thread locking compound. Loctite Anaerobic Sealer is most likely what Jon suggested, I've seen it suggested for sealing carb inlet threads on a few other sites as well. It does work very nicely. In addition, I would suggest dressing the area around the inlet to be flat and square with the fitting, so that you have a proper surface for the gasket to seal against. That is going to the largest part of the problem, and if it isn't addressed, you will continue to have leaks.

I have the anaerobic sealer that I used on the rear main cap. Get out the finest file I have and be careful.
THANKS LONGBOX55

Sharon

here's what i use for a good seal on certain things. fuel lines is certain for me. http://www.hardwarestore.com/block-...mp;device=c&network=g&matchtype=

I thought there was an adapter fitting that threaded into the carb first? Then the fuel line to the adapter?

If it was originally 1/8 pipe and the P.O. Tapped it out to 1/2 straight you may have a hard time sealing that with anything.

From your description it also sounds like its also cross threaded

If the locktite doesn't work you may have to repair the inlet.
...example...


I made the mistake once of using pipe dope in that area. It caused a flooding problem for me. If just one little spec get loose it can cause problems at the needle and seat.
Good luck

You have consider how it was designed to seal. The original setup had a fitting with pipe thread on one end and a flare o the other. The pipe thread was designed to seal against pressure. Ordinary threads are not, they only provide a clamping force.

My situation is a little different, as I'm using Holley carbs instead of Rochester or Carter. In the case of the Holley, they used a 1/2-20 threaded inlet with a gasket instead of pipe threads. I based my suggestion for Sharons situation with the altered Rochester as it seems it is now set up like a Holley.

I think Sharon's carb has been modified and somehow it is using a flat surface. I just can't picture that on the original carb.

I think Sharon is off with her 1/2" size statement.
If she has a Model B Rochester there is not enough metal to drill it out to 1/2".
I think what has happened is someone has overtightened the fitting so it is now bottoming out on the hex part of the fitting.
If I'm wrong I would like to see a picture of what she has there.

I had the very same symptoms on my 235 engine, with Rochester B just installed into my 51 one ton. Yesterday I set out to solve the gas drip. When I removed the gas line from the fitting and inspected the flare very carefully, I could see a slight dimple in its edge. Upon further investigation I could see that there was enough room to install my flaring tool between the gas line fitting and without cutting the old flare off, I was able to re flare the old flare , remove tool reinstall the gas line and the leak was GONE! Jerry