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This is the same venting system I'm planning to use.
Attwood who makes the thru hull vent you are using also makes several that are flush to the mounting surface.
I'm also going to add a marine charcoal canister to eliminate any fuel fumes emitting into the garage or around the car.
I unhooked all the lines, plugged them and plugged the gas tank nipple. Left all the hose on the vehicle along with the charcoal canister in case if and when I sell the car, next owner can hook everything back up. Why did I do this?: Because I went through “three” fuel separator valves and all leaked from the bottom plate. The scary part was not just the fumes in the garage, but lots of fuel leaking onto the hot driver side muffler! I would leave about three inches of a gap from the neck, and still it would leak after fill up. A mechanic told me that original tanks had a baffle near the tank nipple to keep fuel from sloshing into the valve after fill ups. My tank is aftermarket. Nevertheless, the new valves leaks. I used epoxy on one, and hot iron on another to seal it. Didn’t work. I was also using ethanol free fuel available in my area, didn’t work. These new valves suck. Plugged everything up and use a “vented” gas cap, and no more fuel leaks nor smell in the garage. Just my experience on this matter.
I'm sure you can find a modern alternative and keep the EEC system intact. A fuel cell rollover check valve like Richard454 then just figure out a way to plumb it to the EEC hard-lines instead of putting a breather where the antenna used to be if you want to keep it hidden and stock function.
Received my new valve and installed it today. Rochester brand, stamped Made in USA (I hope it really is).
I want to pass along this tip:
There seems to be a high rate of failure with these valves.
I noticed that the larger 3/8 hose had just a bit of a tight curve to it putting a little pressure on the plastic fitting. I believe over time this might have contributed to the housing failure. I lengthened the hose by six inches, giving a very easy curve to the hose before reconnecting. Hopefully this helps. Just wanted to pass along my observation.
Now, off to the gas station to fill up. Hopefully my garage won't smell like a gas bomb tomorrow morning.
Excellent!
Filled the tank to the bottom of the filler neck as usual, absolutely no fumes after driving for a couple of days. Closed up inside the garage at night, next morning, no fumes.
DC, my valve is leaking pretty badly as well, cracked. I just ordered a new one, hopefully it will last for a while. I have always filled my car to the bottom of the filler neck too, without problem.
Greg
Originally Posted by Greg
Received my new valve and installed it today. Rochester brand, stamped Made in USA (I hope it really is).
Where did you get your valve?
Originally Posted by Greg
Excellent!
Filled the tank to the bottom of the filler neck as usual, absolutely no fumes after driving for a couple of days. Closed up inside the garage at night, next morning, no fumes.
Nice! Hopefully you'll get some good life out of this valve. I'm reluctant to try again after 3 bad valves.
I appreciate all the folks who are actively trying to solve the real problem (which is poor quality replacement valves) instead of trying to teach me how to fill up a gas tank.
Very gallant and noble of you Richard, for doing that to help out a brother. I tip my hat to you. Greg, I hope it works out for you. It's very frustrating when you pay 50 bucks for a new valve and they come faulty. I gave up and decided to side with safety. BTW, I ordered mine from different places, that tells me they all buy the same crap from the same source.
Now DO let us know if that solves the problem. It came off my Atlanta car that I've owned since 81- that was taken off the road in 86 with about 100k...sat in a garage/basement till several years ago when I started restoring it.
I would think you are pretty proficient at swapping tanks by now!!!
I'm thinking velcro straps?!!! But then the gas would eat it!!!
Actually it's not that bad. I drop the driver's side muffler down, and reach up with a quarter inch ratchet. In and out in about a half hour. Installed your valve last night Richard, headed to the gas station to fill up. Drove around for a couple hours, then parked in the garage all night. This morning, dry as a bone and not a hint of odor so far.
Thought I would update this thread. Since I made my first post, I've gone through two more fuel separator valves. The last one lasted a grand total of 4 days.
Note to the manufacturer: I'm happy there is a reproduction part being manufactured but it can't just be a reproduction in looks. IT HAS TO WORK FIRST!
While doing my research, I came across many fuel separator valves that I thought might work. Many cars of the 70's had similar type valves. The marine industry has a lot of choices including some very nice mostly metal valves that will stand up to ethanol. Unfortunately, all of these valves require that the inlet be placed above the maximum level of fuel in the tank and that they be mounted vertically. There is simply not enough room above the fuel tank to mount one.
So, after the last failure, I did some head scratching and realized there was a little more headroom above the existing valve. I made a bracket to raise the valve 3/4 of an inch. That allows the top hose to just barely clear. 3/4" isn't much but I figure it will help some.
I then decided to take some preventive measures to guard against external leaks. I coated all of the seams of the new valve with Seals-All which is one of the few readily available sealants I could find that is gas and oil resistant. After the Seals-All dried, I then coated most of the valve with JB Weld. I had used JB Weld to repair another valve one time and it held up well until the valve failed internally.
I connected the new valve with 6' of fuel hose which I ran on top of the tank and around the filler neck in such a way that fuel would have to make somewhat of a 180 degree turn and then flow uphill through 6' of hose to reach the separator valve.
As of this writing, the new valve seems to be working as it should. Hopefully, it will get me by another few months.
I've been planning an EFI conversion anyway so my next step will be a new EFI tank complete with baffles and all connections including the vent near the top center of the tank. The existing vent location was a poor design choice as evidenced by GM getting away from it in later years. Hopefully, having the vent on top near center will prevent fuel from being able to slosh into the vent hose. I'll still run the valve if needed but I think the key to longevity is keeping fuel out of the valve in the first place.
Actually it's not that bad. I drop the driver's side muffler down, and reach up with a quarter inch ratchet. In and out in about a half hour.
This post reminded me of something I forgot to mention previously. My mufflers are welded on so the only way to change this valve without dropping the tank is to work one handed and with limited vision. It's doable but can be frustrating. The hardest part is holding the new valve and mounting bolt in one hand while using the same hand to start the bolt.
What I did was to use some longer bolts and to thread them into the mounting bracket from the backside. I had to slightly bend the bracket down to install one of the bolts. This way I now have studs I can hang the valve on first and can then use a nylon locking nut to secure it. Makes it much easier to work one handed.
If you have the tank out or the body off the frame while working on your car with one of these valves, I'd turn the bolts around before you button everything back up to make it easy to replace this valve in the future.
Thought I would post a pic of one of these separator valves cut apart so people could see how they work.
The chrome metal piece slides into the brass tube with the pointed end up. When gas enters the valve, it floats the ball up which pushes the pointed end of the chrome piece into the small orifice at the end of the brass tube which is supposed to prevent fuel from getting into the vent line.
The reason this particular valve failed is that the sides had collapsed and pinched the ball tight enough to keep it from floating. The bad valve in the pic in post 37 also had collapsed sides so that may have been what caused the seam to open up. Apparently, these reproduction valves can't handle the ethanol in today's gasoline or something else has changed from the original OEM valves.
Current Reproduction Fuel Separator Valves Are Dangerous
I give up. Latest valve has failed. Went through two valves within a couple of weeks recently and four in the last year. I've now concluded that the current reproduction fuel separator valves are dangerous and should not be used. I'll be capping my vent line and switching to a vented gas cap until I switch to fuel injection.
I don't know if it is the ethanol in today's fuel or if the reproduction valves are just cheap pieces of junk or both. Two of the four failed when the bottom seamed opened up. One failed internally and allowed fuel to flow into the vent line. One failed both ways - it failed internally first and then before I could change it, the seam opened up.
One thing common in all four is that when I pulled them off after failure, the sides were all warped a bit. On those that failed internally, the sides had collapsed to the point the ball was trapped and could not float.
Dripping fuel on a hot muffler is not good.
I hope someone's Vette doesn't burn down because of these POS valves. Use at your own risk.
If anyone wants to eliminate the valve and run a vented gas cap, the Stant vented gas cap part number is 10853.
