TheSamba.com :: View topic

Thu Dec 07, 2017 1:38 pm

I'm thinking of capping off all of the vent lines on my fuel tank, along with removing the expansion chamber and charcoal canister. Reason being the strong fuel smell I keep getting when making left turns and not wanting to run all new hoses, along with figuring out the charcoal canister connection at the aftermarket air cleaner.

I just ordered two new filler neck seals and my plan is to cap off all the nipples but one. This one will be used as the only pressure relief line in the tank. One question, should I add some type of fuel filter (maybe even a small charcoal filter) to the line or just run a simple fuel hose to the front/bottom of the car as the older models did?

Thu Dec 07, 2017 2:24 pm

Joey - I have been thinking - several months now - that a charcoal water filter cartridge - like from Home Depot could be used as a charcoal trap for fuel vapors, and yet allow venting. I just haven't tried that yet, but I don't have the issue you do..

Thu Dec 07, 2017 3:12 pm

I was thinking of either selling the charcoal canister and expansion tank or opening the canister and using some of the charcoal on a smaller filter attached to the single vent hose.

Thu Dec 07, 2017 4:44 pm

1. close all venting, and your tank can be crushed by the vacuum pulled by a pump, or if your lucky, the engine stall first from lack of fuel flow.

Your tank NEEDS a vent.

Charcoal tanks can be refilled if need be, go to a wreck, find a tank of a new low mile wreck, buy its cannister, cut both open and replace the Bugs charcoal with new.

frankly a cannister with ruined charcoal, clogs, in itself should not be the cause of the fuel odors. also be sure to look three other places, the bottom fuel hose to chassis pipe, the get old, and sweat gas before they rupture sometimes. check the hise near the tranny, above the left axle, and finally the hises in the motor compartment.

Without a working charcoal system you will have fumes, the old bugs had a vent, it was a hose hooked to a nipple just under the gas filler, on the neck (filler was on top of tank, in the trunk) That hose was routed down, thru the body near spare tire well, ending under the chassis, ponting straight down. that was the vent
this old style vent kept the fumes out of the trunk, and hence cabin, but still allowed fumes to build up and stink up a garage.
The charcoal system in modern cars starting in the 70s or theres about can prevent the garage odor problem, plus it is a handy way to keep the air clean, evaporated emmisions are a major problem without the charcoal can.

Suggest you fix it. where ever possible use high grade fuel hoses in place of lower grade vapor hoses, this will ensure long service, fix it once with high grade fuel hoses.

GOOD LUCK, Bug On, even if it's stinky!

Thu Dec 07, 2017 5:20 pm

Change the filler neck seals and see if that solves the smell problem first.

Thu Dec 07, 2017 5:58 pm

You can cap off all of the tank vents and go to a system like this.

Run the small little hose on the filler neck up high then it exits on the drivers side of the car just below the tank. This is how they came back in 69. No canisters, filters etc.

Thu Dec 07, 2017 6:29 pm

joey1320 wrote: ... strong fuel smell I keep getting when making left turns ...

Could be the filler neck, but this is also the exact symptom of a bad gas cap seal. I had this symptom and it turned out the seal around my gas cap was dry and cracked completely in half.

Kris

Thu Dec 07, 2017 6:58 pm

kpf wrote: joey1320 wrote: ... strong fuel smell I keep getting when making left turns ...

Could be the filler neck, but this is also the exact symptom of a bad gas cap seal. I had this symptom and it turned out the seal around my gas cap was dry and cracked completely in half.

Kris

The cap is less than a year old. The one that was on the car was had a cracked seal and I replaced it because of it. It did it before and after. I'm going to install the filler neck seals and see what happens.

Thu Dec 07, 2017 7:36 pm

kpf wrote: joey1320 wrote: ... strong fuel smell I keep getting when making left turns ...

Could be the filler neck, but this is also the exact symptom of a bad gas cap seal. I had this symptom and it turned out the seal around my gas cap was dry and cracked completely in half.

Kris

me too...gas cap

Thu Dec 07, 2017 9:44 pm

My '69 and '70 Bugs were/are vented to atmosphere.

But the large rubber hoses on my filler neck came with a thin rubber liner in the hose. See if that's missing.

My '69 has that thin rubber liner but my '70 doesn't. Every now and then I'll get a whiff of gas in the '70 with a full tank.

Tue Dec 12, 2017 11:20 am

Multi69s wrote: Run the small little hose on the filler neck up high then it exits on the drivers side of the car just below the tank. This is how they came back in 69. No canisters, filters etc.

Can you explain where this little hose should run exactly? Is it open on the end and just tucked up in the pilar somewhere? How long should this hose be?

Edit: https://www.thesamba.com/vw/forum/viewtopic.php?t=690114 seems to have answered my question, but now the tank on my '69 doesnt have the driver side nipple. So it must not be the right tank.

Tue Dec 12, 2017 11:36 am

goober wrote: My '69 and '70 Bugs were/are vented to atmosphere.

But the large rubber hoses on my filler neck came with a thin rubber liner in the hose. See if that's missing.

My '69 has that thin rubber liner but my '70 doesn't. Every now and then I'll get a whiff of gas in the '70 with a full tank.

I placed an order for the two neck seals. I'm hoping to work on the car this week.

Tue Dec 12, 2017 12:56 pm

MattPierce wrote: Multi69s wrote: Run the small little hose on the filler neck up high then it exits on the drivers side of the car just below the tank. This is how they came back in 69. No canisters, filters etc.

Can you explain where this little hose should run exactly? Is it open on the end and just tucked up in the pilar somewhere? How long should this hose be?

Edit: https://www.thesamba.com/vw/forum/viewtopic.php?t=690114 seems to have answered my question, but now the tank on my '69 doesnt have the driver side nipple. So it must not be the right tank.

Read the entire thread you referenced. Many people (including me) reported that their original 1969 fuel tanks don't have the left side vent ... VW added it later.

Tue Dec 12, 2017 4:28 pm

I had bad gas smell then I sealed up the wiper motor, fresh air motor cover in the trunk smell went away. I do not have a charcoal filter it was removed by the PO.

Tue Dec 12, 2017 5:59 pm

allenw wrote: I had bad gas smell then I sealed up the wiper motor, fresh air motor cover in the trunk smell went away. I do not have a charcoal filter it was removed by the PO.

It seems to me as if you only "band-aid" the real problem. Yes you no longer have the smell in the cabin but it doesn't mean the fuel system isn't leaking. A properly sealed fuel system shouldn't smell.
:(

Tue Dec 12, 2017 8:40 pm

Don't cap the vents on your tank. I did this thinking I could get around it and the tank was likely the crush on itself.

The lines are cheap. Run the vent line up and over the fuel tank. It goes up for a reason which is to keep fuel from running down it.

If you need a charcoal canister you can get one off the classifieds for around $20-$25. They don't need to have good charcoal in them. They just need to be in decent condition.

Tue Dec 12, 2017 10:09 pm

kawfee wrote: Don't cap the vents on your tank. I did this thinking I could get around it and the tank was likely the crush on itself.

The lines are cheap. Run the vent line up and over the fuel tank. It goes up for a reason which is to keep fuel from running down it.

If you need a charcoal canister you can get one off the classifieds for around $20-$25. They don't need to have good charcoal in them. They just need to be in decent condition.

I wasn't planning on completely capping off the tank. I'm well aware of the vacuum created by suction of the fuel pump.

I did work on the car and it was quite obvious what the problem was the moment I removed the filler neck coupler - the seals were not present.

So I installed the new seals and capped all but one of the evap hoses. The one I kept opened was then connected to the metal line that routes above the expansion tank and runs to the back of the car. That line is not attached to anything by the charcoal canister so it's venting by the right rear corner. Hopefully my fuel smell is gone.