Filler Cap...

[Carl Beck]

Hullo Carl B.

I have plenty of problems with aged and leaking hoses on my 1973 JDM Fairlady 240Z. .....snipped....

....snipped... I am interested in your comment that the Vent Tank and hoses can be dispensed with. That makes sense, but can you give me some guidance on how to do that please?

Any comments/feedback that others can provide would be greatly appreciated.

Regards, Jack

Hi Jack:

Dogma240- aka Dave wrote a good article about how to eliminate the evaporative emissions controls.

In the menu at the left - hit the hyper-link that says "Fourms"

THEN:

-Publication Forums

- - Technical Articles

- - - Articles From Our Members

- - - - Treating inside/outside of gas tank with POR-15 and removing evaporation tank

Or the direct URL.... <a href=http://www.classiczcars.com/forums/showthread.php?t=19034 TARGET=NEW> Dave's Article </a>

The information you want is somewhat intermixed with the entire fuel tank refresh.. but pay close attention to Post #14.... that 180 degree turn, held open with rigid tubing is very important....{1/4" copper elbows fit just fine inside the 5/8's fuel line)...If you use just fuel line, it will kink and shut off the vent...

At Post #11 Dave used a threaded nut to cap off one of the vents... I used a 1/4" copper pipe cap and JB Weld... worked great..

hope that helps,

Carl B.

[Arne]

I'd recommend something other than copper, I've heard copper reacts with some of the additives in gasoline.

[jackwarnock]

Hullo All

Thanks for your inputs. After reading other Posts and reviewing what I have in front of me I believe I can sort this one out. Certainly a complicated set up with so many different hoses of different sizes.

I feel confident I can either fix problem with Vent Tank (new hoses) or just have the main hose (19mm or 3/4") with the 180 degree bend from top of fuel tank to fuel filler. I have made contact with Australian supplier who has this pipe new, so that is the main hose dealt with. He will also supply me with a new fuel filler tube. I don't want any issues with it, so better to replace now whilst all the gear is off the car, than come back to it later. The other hoses are more straight forward.

Now I will get on with it.

Thanks again for your collective help!!

Regards, Jack

[DaveN]

If you eliminate ALL the gas tank vent hoses you'll have problems, they do more than just keep the car legal in California. The filler cap makes an air tight seal when in good condition, so you need a small vent for pressure relief and to be a vacuum breaker. For safety that line needs to contain (or be small enough to be) a flame arrestor. The little vent hose from the vapor/liquid separator tank to the engine in the quarter panel does that job, and the separator needs a low point liquid drain back to the gas tank. Finally, early Z gas tanks need one fairly large high point vent to fill completely because the filler neck enters well down on the side.

[Carl Beck]

Hi DaveN:

I believe that Dave's article referenced - addresses your concerns. It reduces the number of vapor lines in the cabin from 5 to 1. It retains the vent line to the engine compartment so air is replaced in the tank as gas is drawn out. It eliminates leaking/cracked vapor canisters and the usually cracked plastic connector from the filler.

Arne:

There may or may not be issues with the use of copper for fuel lines - but it's limited exposure and use for a vent line is unlikely to present any problems. Nonetheless if anyone can find handy replacements other than copper - I can't see how it would hurt.

Jack seems to have found an OEM replacement with a molded in 180 degree turn.. so that only leaves the possible replacement of the plastic connector between it and the filler neck.

Jack:

Not a bad idea to replace the fuel filler neck - but if you take the old one out, and find it's still good, hang on to it - - they are getting expensive and sooner or later they well be NLA...

FWIW,

Carl B.

[jackwarnock]

Hullo Carl B.

Thanks for your comments. I am waiting for the hose with the 180 deg. bend and the furl filler "neck" to arrive, but have obtained all the other hoses - cost about AUD55.00. Overall I will be happy to go ahead and reuse the metal Vent Tank with all new hoses and a new filler neck. That way all the issues regarding filling and venting will be taken care of.

I will ensure a good seal where hoses enter the cabin through grommets etc. With new hoses and clamps those many potential problem areas for fumes/fuel leaks will be dealt with. The generic hoses are good quality, so hopefully will outlast me on the car!!

Thanks again for your help.

Regards, Jack

[New-to-240z]

Just to pull this back,

I was wondering . . .

I have been noticing this recently with my 73. Now, the PO actually had the tank POR'ed inside, but not outside. He also had the hoses replaced with all factory parts. NOW, he didn't replace the filler neck ( from start of filler cap to the tank. I took a look yesterday at it and it has NO cracks or anything, BUT i noticed that after a hard left i have a streak of gas down the rear of the car from the filler door. So, i read on the forums about the Wate Disposal gasket at AceHardware and went ahead and repalced it. It did help, but i still get a small amount of it seeping out. So i took another look and noticed that there is a rubbery like thin gasket that is held down by the neck and (i think) 3 screws. I was wondering if this gasket could be replaced without having to buy a new neck? Is this part of the neck, or is it a replaceable gasket? I really do think this is my minor problem.

[a7dz]

That rubber gasket held in with three screws is the top flange of the filler tube.

[New-to-240z]

can it be replaced without replacing the filler tube? Cause that's gotta be where my gas leak is coming from.

[a7dz]

No it is all one piece. I would check the plastic piece that comes out of the rear of the filler neck they are known for cracks, it attaches to one of the vent lines.

[beandip]

That so called gasket you are referring to is really what is left of the rubber flap that was there to prevent the gas cap from hitting the fender when you filled the tank . Remember the cap was attached to a chain and it is connected inside he filler neck . Arne is right have a good look at the plastic connection on the filler neck . You will need to remove the inner trim panel to expose this and the evap tank . While in there have a close look at all the vent hoses and check for any leaks there also. Gary

[jackwarnock]

Hullo All

I have recently replaced all the Fuel and Vent hoses at the rear of the vehicle, together with the fuel filler neck (complete unit) and the rubber flap that protects the paint work from the filler cap.

The fuel filler was expensive (AUD136) and the hose with the 180 deg bend was too short to reach the Vent tank!! I had to join this with other new hose. I used a brass joiner for that connection and also replaced the plastic 3/4" joiner for the fuel filler with a brass one also.

Job is now complete and it is much better having no more fuel vapours wafting around. Hopefully all those problems are now solved for many more years.

Regards, Jack