Tips on replacing a fuel shutoff valve

dan

dan

Senior Member
Still muddling along with getting my car into decent shape. Next on the list is the leaky fuel shutoff valve inside the car. It's a slow leak (the handle is wet but it is evaporating fast enough that the carpet isn't wet) but annoying for the fuel smell inside the car in the mornings. And on my fingers when I turn it off or on, for that matter.

At the same time, I'm likely going to go ahead and replace the copper line that's currently between the shutoff and firewall with the correct steel line.

Questions:
1. Is it worth buying a complete new shutoff, or should I just purchase a re-build kit?

2. Any hints on what to do to prevent future leaks? Is the packing enough to keep it from leaking, or should I apply some type of additional sealant?

3. A new steel fuel line from the vendors should just fit, right? Or am I going to have to do a bit of work tweaking it? (I'm at the point where I'm considering buying a 1/4" tubing bender and steel tube, since I also need to clean up the copper-tube-to-rubber-hose mess that currently feeds my Weber)
 
1. if it is not a points show car. I would go with a new valve. I have not had much success with the rebuild kits.

2. Installed correctly, the new valve should be leak free for years

3. You can find nice original fuel lines on ebay quite frequently. I'm sure mosst reputable dealers have fuel lines that fit pretty good.
 
Grit in the gas tank scores the valve seat and causes leaks. Get the mesh filter to insert into the intake of the valve to stop the process.
 
'Just a note on new fuel shut-off valves. A few years ago, I had a real difficulty with a customer's car that would run about ten miles, then run out of fuel (no delivery to the carb). It had a 97, a fuel pump and a regulator and a new fuel shut-off valve. I tested the tank, the screen, the shut-off valve, the gas cap for obstructed vent, replaced the regulator, then the pump, and of course, the lines. Frustrating and embarrassing. It was the customer who discovered that the fuel valve wouldn't pass gas(oline) more than a couple drops at a time in the open position, but would flow just fine in the 7:30 position. So as long as the car sat for a few minutes, the float bowl would fill but couldn't get enough to keep cruising. I won't tell you who had purchased and installed the after market fuel valve in the first place. When testing the valve, I had just turned it on and off quickly, and as it passed through the 7:30 position it flowed, so I did not think to test it in the 6:00 position. I wonder how many other people have had the same experience.
 
Another note on the shut off valve fiasco: After the second pressure regulator replacement, I decided to dissect it, even though it would void its warranty. When I opened up the regulator, the diaphram popped out because it had bunched up and swollen to about 125% of its intended diameter, giving me further cause to blame the regulator and its manufacturer for the fuel delivery problem. There is ethanol in the fuel here in Missouri. Though I have heard of its treachery on rubber parts, that was my first bonafide encounter with it.
 
I've always been told to never to use copper for gas lines since it is supposed to be brittle and can crack from vibration.
 
I've had two different copper oil lines crack from vibrationover the years. If you do use copper, make coil of serveral turns at each connection.
 
If you follow the instructions, the rebuild kits work just fine. I'd also recommend a new float valve for your carburetor from Brattons. The new float valve did the trick for me.
 
Thanks to all who replied.

I was at the local chapter meeting and happened to mention my problem to Pat (Hi Pat!) who suggested tightening the nut and sure enough, no leaks. So, no replacement/repair needed, just an operator headspace adjustment :o
 
I getting ready to replace the home made fuel valve on mine (no screen) and replace it with a used one from ebay. I blew through it in the open and closed position and it seems tight. I guess that is good enough to hold back gas?
Pete
 
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