Gas Tank...Evaporative Emission Control, Fuel Smell...Ventilation/Vapor Hoses Options

[vujade]

I just printed out the tech article on the Gas Vapor Recovery System Removal and followed the instructions to a T.

Everything came out as said in the article and I hooked up the hoses as shown in the diagram.

Overall the article was very informative and I would like to thank Superman for providing the info for all to use.

Thanks
Joe

[Superman]

EDIT NOTE: The original tech. article has been moved, it is now included (below) in this post. Read the entire article before you start.

The fuel vapor recovery system on the Super was comprised of several hoses and a charcoal canister located under the right rear fender. Over the years these hoses and the canister become hard and brittle then eventually crack causing fuel vapor to leak out. These leaks are what make the car's interior fill with fuel vapors. The removal of the fuel vapor recovery system is a logical choice since the charcoal canister is no longer available (check with your local supplier, VW part no. 113201891A).

This is a basic overview for all Beetles but the 71-72 Superbug is what's shown in the pictures, also keep in mind that your car may have been modified by a previous owner. This will remove all lines from the old system, once these are removed, give the car a few hours to air out, then replace the hoses on the gas tank in the way that the red lines are drawn in the pictures.

[See picture attached]

Step 1): Remove all hoses and lines (some plastic and some metal). The hoses will also run under the car to the rear. The charcoal canister is held by one bolt under the right rear fender. The hoses are held by tabs on the body and under the floor pan.

Step 2): Place a hose from the fuel filler (A) to the tank (B) and "T" this line (E) to the rear of the car and connect that line to the carburetor or an intake vacuum line. You may use the factory metal line that goes to the rear.

Step 3): Loop a hose and connect the two outlets (C & D) on the top right of the tank.

Connect hose E to a metal line under the car, run it to the rear, and hook a hose to the air cleaner. If there is still a fuel vapor smell, check all other fuel lines including the fuel filler neck and the hose under the tank. Also, check the bottom of the fuel tank itself for rust through or leaks. Below is a view of the overall fuel vapor recovery system. Once the charcoal canister is removed, use a large hose (that went to the canister from the fan) to connect the fan to the air cleaner or block it off. Also, a vented gas filler cap helps to reduce pressure build-up inside the tank. The vented (perhaps pressure release valve is a better term) gas cap on my car was made for a VW Rabbit, Golf, Jetta, & Fox. It is a Stant part number 11819 and it can be purchased at Wal-Mart and many other automotive parts stores.

The fuel vapor is now vented directly into the air cleaner.

NOTE: You should drain all the gas and disconnect the battery for safety before doing anything.

Disclaimer: use this tech article at your own risk. Short of replacing all hoses, lines, and the canister there is no other solution. The hose that goes from the fan shroud to the canister is shown to connect to the air cleaner. It was this or plug it off. Since my car is a 1973 there is no 1974-1979 E.G.R. or (late '80s) A.I.R. system. Any suggestions are welcome. Also, there has been many flame posts about this article with EPA concerns. I do not consider myself an expert and suggest that you do what is in your best interest to comply with your local, state, and federal law(s).

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[71Super]

Hey everyone
I also followed the instructions on my 71 Super; they are great, Superman.
i followed the metal line you are also reffering to. It basically goes under teh tank, by the brake lines, and will go past the passesnger side of the car toward the back, and finally make its way toward the carbon canister, which i've promptly removed.
Every time i'm doing any work under there, i will remove a section of that line, since i'd like to remove any unnecessary deadweight from the car..

I'll post some pics when i get a chance to configure everyhting

[Tcaster]

Hey Bugs -


I have completed all the mod's listed in the tech section of this page and a few others that owners have suggested. Although I can't see any gas on the ground, I'm convinced that I have a leak somewhere and want to replace the fuel line - from the gas tank to the carb. I pulled it out to give it a run around the block ( Pa. and cold this week ) to keep the battery happy and after pulling it back into the garage, it reeks of gas smell !!!

Does anybody know if the original fuel line is available... and where can I get it ?

Thanks - Bill H Perkasie, Pa.

[vujade]

I know this isnt the reply you are looking for, but I did the same mods to my car & sometimes it stll smells of gas after drving it.

What I found out is, that after going round a corner, gas is coming back out of the filler, because of the venten cap and leaking back down into the trunk onto the filler tube.

[Superman]

What kind of cap do you have, it shouldn't do that. Pull the tank itself and check for leaks. I had a tank before that had a small rust hole in the bottom.

[Dorinda & Mark]

For the cost of new gas lines it is worth replacing the few feet that goes from the tank to the tubing running thru the frame and the line going from beside the tranny to the fuel pump. maybe 10 feet of new tubing. The tubing under our 73's gas tank was very crusty and dry when we pulled it off. except of course where the gas soaks in. Thats why there are no drips, but if you go around and squeeze the lines they can be wet.

[vujade]

I bought a Stant Cap at Walmarts (they didnt have the one for the Jetta so I bought one for a Fox)

[nevaryzarc]

check around the sending unit

took me awhile to figure out that gas was coming out around the old one, the gasket was gone, and it wasnt on tight

[Superman]

Vujade, the caps are probably the same. Huh, my car is a 1303 with a Golf/Jetta cap and you have a 1302 with a Fox cap, perhaps something is different but I don't think so. All I know is that mine has never leaked. I'm sorry to hear about this and hope it can be figured out.

[vujade]

well the Fox cap was a different part number then the Jetta cap (they didnt have the Jetta cap)  But the cap fits on fine.

I cant  figure out why else it leaks other then the cap.
I have found gas behind the door around the gas cap & also dripping back down into the trunk area down the fill tube.
This is when I smell gas fumes the most, once it reaches back down into the trunk.  It only happens around a sharp corner with more then half a tank of gas. :(

[Superman]

Well, if it's a different part number than the Jetta and my Jetta cap works then I'd say it's the cap.

[Tcaster]

Hey Vujade & Superman & All -

OK - you guys have me on the hook - that tank is coming out when the weather warms up. I suspected the sending unit may be involved but didn't want to dig that deep at the time. As far as the gas cap is concerned, it looks like a standard Beetle cap, about 3 inches of threaded insert that clicks when it is tight. One last question, is the gas line tubing all the way from the gas tank to the carb ? or is their any rubber hose used somewhere in between ?

Thanks again guys, that smell is toast now ........... BH

[Dorinda & Mark]

There is a hose coming from the tank to the tubing that run thru the chassis. If you have a gas heater there is a T under the tank that splits the line and half goes to the fuel pump for the gas heater. The line exits the chassis next to the tranny on the drivers side and goes thru the back of the engine tin to the fuel pump. Ours has a fuel filter next to the tranny.

[Superman]

The tube exits the chassis in the rear about 2 inches then there is a hose to a piece of tubing that goes to the fuel pump.

[PunchBug]

Another thing to check is the large rubber/material pipe that connects the filler tube with the tank.  I was having the same issues whenever the tank was full -I would have gas smell.  Turns out the pipe was seeping due to age.  

Gas tanks leaks are usually pinholes - they rust from the inside out.  After having pulled my tank and attempting repairs, I've come to the conclusion that I'm just going to replace it.  When I do, I'll get one of those kits that etches and lines the tank with an epoxy like material.  That should keep it for a few more years.

[Tcaster]

Hey Punchbug & D & M -

Thanks for the additional feedback, I am optimistic that when I remove the tank all my questions will be answered. As far as the filler tube hose is concerned, I replaced that early last year and still have a chunk left over. Now to start shopping for a replacement fuel line....hummm.... Rocky Mt ? Jbugs..? Wolfburg West....I wonder who will have it at a fair price ?

Thanks again  :cool:

Bill H - Perkasie, Pa.

[JimmyPringles]

OK, all these ventilation/vapor hoses coming off the gas tank...can I remove them??  Obviously they're for emmission controls, but I dont have to worry about this, cuz the year of my vehicle for my state only has to pass a safety inspection (which already did).
I already removed the charcoal box and all the air hoses to the carb/air box[the big plastic one] etc, and just placed a typical chrome 6&3/8 air filter on (of which seemed to make a drastic improvment in the cars overall acceleration).  
The vapor lines to the charcoal box, I just left hanging there.
I want to remove the rest of the lines up by/on the gas tank (i like simplicity).  Will removing all these hoses (and the odd long white plastic thingy [sorry] that is above the access panel to the fan, to which they connect) be bad, dangerous or just not as friendly to the enviornment as it was.  Upon removing them (if OK), what should i use to block off where the hoses came off of the tank.
Sorry if that all seems kinda vague, my 77 doesnt seem to have any of this, because of the engine mods..made prior to my ownership.  My 63, well that just has one little hose that comes off the filler neck, and just hangs to the bottom of the car for some road draft suction.

[Loaf]

Jimmy,
    Noticed your from Queens, NY.. I was a Queens local Myself.. Lived by Elmhurst/Maspeth.. By the old Gas tanks that are there no more.. Left Queens for College, the Service, and no I'm across the River,NJ
Greetings...
ALex

[JimmyPringles]

whats up Loaf.  yup, i live in Bayside.  pretty much lived here my whole life.  i was just watching a movie (the Jerky Boys)the other night & it had the 2 old gas tanks in it.  forgot they were even gone.

[Jackson]

Hi Guys, I'm brand new to this form. I've been debating on how to eliminatre all that evaporative plumbing on my 74' Vert.
My canister is plastic and is smashed. I have all of the other pieces / parts connected. My question is if you modify the lines as depicted in red, how does the tank breath? The OEM method pulled fumes out of the tank, right? Will plugging all the lines cause fumes to build up in the tank. OR is the key the new gas cap that lets the fumes escape into the atmosphere? Thanks for your response, I'm looking forward to "chatting" with everyone.

[uberbug]

Its not a problem that the fumes build up in the tank, the problem becomes that when you consume gas there is no way for the air to replace the missing gas and you'll get a vacumn and eventual fuel starvation.  There is a Jetta vented gas cap that will fit the bug and allow the intake of air.  Search this board for the model of the cap.

[PunchBug]

Search this board for the model of the cap.

part number is mentioned on the above link....

:cheese:

[Superman]

What you could do is put a T fitting on the hose (in red line, by the filler neck) and run that back to the fan housing. This will let it breathe; I did not do this to my car, as the article says I did that procedure to my 1973 and it worked. Also, as stated "do what is in your best interest".

[Bugorsh]

I just did the rehose thing to my tank and teed into the line going to the filler neck and connected it to the metal line still left after removing the long plastic tube/cylinder.  This line is connected to the  metal line that goes back to the charcoal canister.  I removed the short rubber hose that connects them ( it is down by right front wheel and runs by the running board)_ This allows for any overpressure relief outside the car and also allows make up air into fuel tank so you do not get a vacuum inside as the fuel is sucked out.  By the way, a VW mechanical fuel pump has the capability of physically sucking the fuel tank 'flat' if no air is allowed to vent into the tank as the fuel is removed.  FYI :0