Fuel tank evap hose leak and tank fuel level question

[hotsho111]

Hey, I went to try and fill my 240z to a full tank for the first time and after putting in ~5.5 gallons (from a little under 1/4 tank on the fuel gauge) noticed a decent amount of fuel coming out the bottom of the car. I got underneath the car and noticed it was leaking a lot from the evap hose at the top/rear of the tank. The hose looks a little kinked and it looks like it was pouring out from where it was kinked. It was leaking down from that spot to the front corner of the tank and down from there. I *think* that's the only source of the leak. The car leaked for quite a bit before it finally got below the level of that hose and stopped. The fuel gauge is sitting at just under 3/4 of a tank now.

I've been reading through a few threads and haven't quite found answers on these but I have a few questions: 

1). The car is pretty new to me so I don't know how accurate the fuel gauge is but if it's leaking out of that evap hose, that basically means the tank was fueled to full right? Was it overfilled at that point?

2): Can I drop, but not remove, the tank to replace the hose? 

Thanks!

[Pop's Z]

My guess is that like many of these cars that are 50+ years old ALL the hoses in your car will need to  be replaced, not just the one you have found with an issue. If you have looked at the service manual (available on this site by searching)you will see that there are a number of hoses attached to the tank. All will need to be replaced for peace of mind at least. Once again, search is your friend as the gas tank and it's various issues has been discussed with great regularity here. You won't be able to easily just drop the tank part way. This is one of those jobs that will become..."while I'm at it, as long as I have it out..." Ask me how I know. Good luck

[siteunseen]

Agree with Pop's Z. You'll want to get them all while you're doing it as the others are sure to fail also. I bought all my low pressure fuel hose at o'Reilly's auto parts. Don't use heater hose. For the 180 degree bend you can use 2 PEX 90s and some clamps. Me and some others have done it without any issues. You'll have to remove the back panel of the hatch that covers the backside of the brake lights. You might can reuse the plastic rivets that hold it on but if not they're still available from Nissan or Z specific vendors like zcardepot.com.

Here's some good threads to read through before you tackle the job. Good luck. Plenty of help here when you need it.

https://www.google.com/search?q=240z+evap+hoses+classiczcars.com&client=ms-android-americamovil-us-revc&ei=9SS-Yq7VFpOxqtsP-YGkiAs&oq=240z+evap+hoses+classiczcars.com&gs_lcp=ChNtb2JpbGUtZ3dzLXdpei1zZXJwEAM6BAgeEApKBAhBGAFQlxRY3Upg4lNoAHAAeACAAYYDiAHjEJIBCDAuMTAuMS4xmAEAoAEBwAEB&sclient=mobile-gws-wiz-serp

[hotsho111]

Thanks guys, this car was restored around 2010 but was sitting for a while before the last owner sold so I don't think all the hoses are quite that old. I understand how the hoses run and how to replace them, I just wasn't sure if I could replace just that rear evap hose without dropping the tank and couldn't find an answer on that. The job itself doesn't look too bad outside if the hassle of it haha

I was looking at using a unicoil to make the 180" turn for the rear hose. I don't think I want to spend the 80 bucks on a oem (ish?) replacement

[dutchzcarguy]

I saw my (usa ) car had a evap tank and normally a euro does not have that.. i took it out and it saves a LOT of hassle with new rubber tubes because the euro version only uses 1 ! rubber hose , so you can close the extra outlets on the tank and one outlet to the top from the fillerhose is enough..  Now you will have only 2 hoses..

[hotsho111]

I got under the car and took a look at some of the other hoses and while not leaking look a bit cracked. 

The OEM hoses are a bit too pricey for me so I'll probably drop the tank at some point and replace all the hoses with off the shelf fuel hose

[dutchzcarguy]

5 hours ago, hotsho111 said:

replace all the hoses with off the shelf fuel hose

There is at least one tube with a bend in it that you will squeeze closed with regular tubing.. get rid of the plastic evap tank (they brake as well (ageing) )  and you need only one tube iirc.

[HusseinHolland]

Rather than start a new thread on the topic, I figured I'd add to this one.

75 280Z CA spec

I can't find any threads that actually itemize the hose sizes & lengths needed if one is refurbishing the vapor hoses. I've found sites selling 'kits' for the 240Z.

Or, alternatively, eliminate the vapor tank & just have the tank vent to filler neck and vapor line to charcoal canister.

Anyone got specifics on either option? I'd like to know I have the correct ID hoses before I do drop the tank.

 

[hotsho111]

I took a look at both options (it's basically my winter project for my 240z). I initially was going through and finding the lengths and diameters of all the hoses (they aren't all the same which is super cool), and even looking into ways to get the weird bends that the top evap hoses need.

My car is mostly original, but has some QOL improvements so I don't feel the need to get all original parts, and I've seen some full hose sets for ~200-300 I might investigate a little further. If I have some time to wrap up my research I can post the varies sizes, but no worries if someone beats me to it haha.

 

 

 

[hotsho111]

Took way longer to get to this than I was hoping, but finally got this project underway. I've got some fuel hose on the way

I found a complete tank kit from 240.life (https://240z.life/product/fuel-hose-kit-for-fuel-and-vapor-hoses/) but it was a bit more than I was hoping to spend, and most of the fuel lines in my car have been replaced with non-cloth braided ones so being period-correct wasn't too big of a concern.

Referencing this post: 

 

I went about measuring all the hose sizes I'd need and then started looking for appropriate fuel hoses and came up with two options from Gates and Continental but basically the measurements I ended up with for each hose and size:

• 3/16 - not totally sure but I think a fuel return line
• 5/16 - 48" - line from the metal fuel return rail to the top of the evap tank. This is also the fuel supply line hose size
• 3/8 - 32" -  top connector on the front of the tank (this is the one with the complicated bend and people just tend to by a repro hose)
• 1/2 - 80" - connector at the driver side rear of the tank (this is the easiest one to access)
• 5/8 - 51" - the "U-shaped" hose at the top rear of the tank. This looks like it was the original hose and it was cracked on mine so when I tried to fill the tank I ended up getting a leak out of this one
• 3/4 - 15" - connects from the evap tank to the fuel filler neck

These aren't necessarily 100% accurate and leave a little headroom but some part numbers for the Gates and Continental hose:

Continental (note these are numbers from larger rolls, but this was the PN where I could buy them by the foot - https://www.tdiaustralia.com/product/fuel-line-emission-control-hose/ has more info):

• 3/16 - 20027934
• 5/16 - 20027995
• 3/8 - 20028045
• 1/2 - 20028115
• 5/8 - 20028134
• 3/4 - 20028141

Gates:

• 3/16 - 27001
• 5/16 - 27003
• 3/8 - 27004
• 1/2 - 27006
• 5/8 - 27008
• 3/4 - 27010

I ended up going with contintental as it's s till made in the US.

The hose should get in tomorrow so I spent the day removing the evap tank and disconnecting as many of the fuel hosts as I could from the tank.

I'm going to do a little crafting to try and get the appropriate bends in the hose and will report back

I have a feeling the inside of the tank is going to have some rust in it so I might need to deal with that but want to wait till it's fully trained so I can scope it.

 

Edited March 2 by hotsho111

[hotsho111]

Making a separate post to ask this question. There is a gap in the frame that looks like it's for a fuel hose to go through. The hose that's run through that currently is the 3/8" hose that connects to the top of the fuel tank with the U shaped bend in it. 

To me, it seems to make more sense for the 5/16" hose from the fuel return rail to go through that hole, because that's more likely to stay attached to the car. I'm not sure what the expectation is for being able to drop the fuel tank with that hose running through that hole, because you can't access the fitting to remove the hose and the 5/16" evap line is *below* that line. It seems like that would make it way more difficult than it needs to be

The 3/8" hose with the unicoil is the one running through the frame rail. The one underneath is the evap hose from the metal fuel rail

Another angle the hose on the bottom is the hose from the fuel rail

I found another thread that indicated that was the hose to go through there, but it's pretty inconvenient.

They couldn't have done a worse job planning all these hoses for the tank haha.

Edited March 3 by hotsho111

[hotsho111]

Had to use a little heat on the fuel filler neck to get it off, but managed to get the tank dropped. It looks like someone tried to coat the inside, but didn't do the best job and there's a bunch of rust in it so I'm probably going to just restore the whole thing while I'm at it.

In other good news, poked around at calibrating the fuel level gauge and I think I'll be able to get that into a more accurate spot.