73 vapor hose wet with fuel

[Douglas C.]

Please see pic. Hose end from separator wet with fuel at metal line, top of hose end at separator is dry. I did have slight vacuum leak at PCV so carb and PCV cannister hoses in air for now. Everything else is correct and dry, correct non vented gas cap. Car recently restored by member, all hoses, clamps, etc. new and correct. Thoughts? Doug 20220405_105455.jpg

[Jimmy P.]

Re: 73 vapor hose wet with fuel

Doug,
Shouldn't be any raw fuel leaking back there if the fuel Seperator check valve is working properly and not leaking. That line should just be to vent fuel vapors up to the EVAP Canister. Looking at your picture not sure what I'm looking at where the hose meets the metal line (see my arrow). Seems like a gap there? Plus the red clamp seems pretty far up on the hose maybe it isn't clamping to the line...just around the hose?

[Douglas C.]

Re: 73 vapor hose wet with fuel

Doug,
Shouldn't be any raw fuel leaking back there if the fuel Seperator check valve is working properly and not leaking. That line should just be to vent fuel vapors up to the EVAP Canister. Looking at your picture not sure what I'm looking at where the hose meets the metal line (see my arrow). Seems like a gap there? Plus the red clamp seems pretty far up on the hose maybe it isn't clamping to the line...just around the hose?

This is the hose coming down from the separator, and that hose end is wet at the metal vapor line on the frame which runs along frame to the cannister. Hose at cannister is dry and no gas smell. Driving the car you smell fuel. Doug 20220405_132904_002.jpg

[John S.]

Re: 73 vapor hose wet with fuel

Doug, I agree with Jimmy that there should be vapor only in the return line from the canister to the tank. If you have fuel in that line or a significant fuel smell I would check everything from the canister back to the tank to make sure that the flow is open and unobstructed. There is a fuel separator valve mounted on the top left of the tank, check the web there are several sites that state how to check it for proper operation.

There should be two rubber hoses at the seperarator, one from the steel line to the separator and one from the separator to the tank. They may be new but perhaps one of them is kinked. My bet is you have a bad separator valve or a blockage somewhere, good luck.

[Douglas C.]

Re: 73 vapor hose wet with fuel

Doug, I agree with Jimmy that there should be vapor only in the return line from the canister to the tank. If you have fuel in that line or a significant fuel smell I would check everything from the canister back to the tank to make sure that the flow is open and unobstructed. There is a fuel separator valve mounted on the top left of the tank, check the web there are several sites that state how to check it for proper operation.

There should be two rubber hoses at the seperarator, one from the steel line to the separator and one from the separator to the tank. They may be new but perhaps one of them is kinked. My bet is you have a bad separator valve or a blockage somewhere, good luck.

Just blew out frame line from canister to rear of car, wet fuel in line. So I will pull seperator and look up how to check. No kinked lines. I will also pull canister and rebuild as I did also have small vacuum leak from PVC hose to canister. Tks. Doug

[Douglas C.]

Re: 73 vapor hose wet with fuel

Ok, pulled fuel separator and lower flat bottom base leaks air. Found test saying right side up passes air thru tube, turn upside down and air should stop. I held the leak with fingers and the test seemed to work. Not sure if can glue bottom to seal it. Test also says it should rattle like a PCV and that did work also. So, are repros worth getting or should I try to fix it.

Also does someone have procedure to rebuild the charcoal canister?
Tks. Doug 20220405_184808.jpg

[John S.]

Re: 73 vapor hose wet with fuel

Doug, no personal experience with the repros but I’ve seen a few folks not happy with them on CF. Might be worth trying to fix, other than the pain to R&R it’s worth a try.

The other possibility is the valve is not functioning properly and it allows fuel to slosh into the return line then collect at the lowest point which is probably the hose connection at the canister.

[Douglas C.]

Re: 73 vapor hose wet with fuel

Doug, no personal experience with the repros but I’ve seen a few folks not happy with them on CF. Might be worth trying to fix, other than the pain to R&R it’s worth a try.

The other possibility is the valve is not functioning properly and it allows fuel to slosh into the return line then collect at the lowest point which is probably the hose connection at the canister.

Yes John I'm tempted to try to fix as it seems to pass the tests. The rattle is supposed to prove the valve is working. Only other issue is it was a body contorting test getting it out. Probably harder to get back in. Tks. Doug

[Jimmy P.]

Re: 73 vapor hose wet with fuel

Yes John I'm tempted to try to fix as it seems to pass the tests. The rattle is supposed to prove the valve is working. Only other issue is it was a body contorting test getting it out. Probably harder to get back in. Tks. Doug

Doug,
Consider yourself pretty lucky in that it took so long for this "original" valve to start leaking at the bottom seam. I know you've just recently purchased the car. Knowing who you purchased the car from the valve could very well be the original or he may have been able to find a really nice slightly used original to replace it with. I've been studying these a little bit and I've found that all (or every one that I've been able to find used) of the original valves all have added " factory sealant" of some sort added to the bottom seal. So, they may have known something back then! None of the new reproduction valves have this added protection! As you can see in the photos below it was rather sloppy and somewhat heavily applied. Another clue that the valve is an older factory original is that they all have a "hand engraved" number scribed into them. Usually, always a three-digit number. Not sure what it stands for though. Possibly a date code, doubt it.... or maybe some type of inventory number. Anyway, I've attached some photos showing an original with the added sealant and engraved numbers, as well as a leaking bottom seam repro, and one repro that has collapsed.
As you well know now these things are a PIA to get to. I find it easier to remove the rear muffler/tip hanger letting the muffler drop down a little. Gives you a little more room to work. Also, be very careful not to cut your wrists on the sharp gas tank edge. I always run a piece of duct tape along it to save my wrists and arms.
Since I purchased my '73 in 2014 I've had to replace this part three times. The valves were all newer repos that all the vendors sell. So, I started watching ebay for good non-leaking used originals and pick them up every chance I get. (None for sale?) The one on my car now is a used original...so far so good!
The last one I replaced actually collapsed (see photo below) which kept the ball inside from doing its job.
As for repairing one. I've heard of guys successfully using J-B Weld along that bottom seam as a repair fix.
Other recommendations out there:
1. Never over fill the tank to the very top!
2. Bi-pass the valve & EVAP cannister by removing the tank over-flow hose from the valve...plug it with a bolt & clamp it, and replace the "sealed" gas cap with a "vented" cap.
Hope this info has been useful.
Have fun!

[Douglas C.]

Re: 73 vapor hose wet with fuel

Thanks a lot Jimmy. Here is mine with three digits. I am going to try to seal the seams with Seal-All. Supposed to resist fuel. I'm test for leaks on the bench after. I assume since this car was hardly driven on street and now that I am using it these things can get disturbed. Car overall is so well done I'm fortunate to have it. Doug 20220406_093856.jpg20220406_093820.jpg

[Jimmy P.]

Re: 73 vapor hose wet with fuel

For sure! Try to reseal this one. I'm thinking with today's gasoline additives etc. it just eats away at these over the years, which causes the failure to this part (also called a "rollover" check valve). Happens much quicker on the repros vs. the originals it seems.

[Jimmy P.]

Re: 73 vapor hose wet with fuel

Also does someone have procedure to rebuild the charcoal canister?
Doug,
Just sent you a personal email with my procedure & photos for rebuilding one

[John S.]

[Douglas C.]

Re: 73 vapor hose wet with fuel

Ok, resealed original fuel separator, and thanks to Jimmy for his procedure to rebuild the charcoal canister, which I finished yesterday. Took car for a ride, no fuel or fumes smell. Hope the separator fix holds up.
Tks. Doug 20220407_143811.jpg20220407_143157.jpg20220406_134958.jpg20220407_180208.jpg

[John S.]