240Z fuel tank breather hoses | The Z Club of Great Britain
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240Z fuel tank breather hoses

Discussion in 'S30 (240Z,260Z,280Z) General' started by Paul_S, Sep 17, 2019.

  1. Paul_S

    Paul_S
    Z Club Member

    I had a very interesting conversation with MrF earlier today (thanks Mike!)

    I was enquiring about a set of breather hoses for my US import 1971 240Z (there are pretty much no hoses available) but he pointed out that UK cars didn't have all that gubbins and were a lot more simple. He described what they had and I did a little digging.

    I came across this blog about a mod the chap did to 'Europeanise' his fuel tank breather. This was his design (from the US version on the left to his design on the right):

    [​IMG]
    This looks like a lot less hassle and a lot cheaper in components! But my question is, do you think there's a need for the lower hose that connects the 2 breather pipes? I can't see what the benefit is and am tempted to just blank off those 2 pipes leaving just the top breather going up to the filler neck, and then down to exit beneath the car.

    What do you reckon? And would you happen to know the ID of the pipe I'd need?

    Thanks :)
     
  2. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    All it is is just a t piece it's very simple. It should be the same size as side outlet on the fuel filler neck.
     
    Paul_S likes this.
  3. Paul_S

    Paul_S
    Z Club Member

    Thanks. I was hoping that would be the case. Sometimes they like to have hoses with a different ID at each end. I hate it when that happens!
     
  4. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    It did have a smaller id coming off the t piece which go up and is usually fastened above the fuel filler and then goes down into the that wheel arch space through a rubber bung so it ends up behind the fuel tank splash shield.
     
  5. tyroguru

    tyroguru
    Z Club Member

    Are there any downsides to doing this? I need some new breather hoses but this seems like a better option for me if there aren’t any drawbacks.
     
  6. Makesy

    Makesy
    Z Club Member

    After I spent a good amount of time looking for suitably sized alternatives, the general consensus seems to be a T piece from the filler neck and a step down connector. Convert the hose to 1/2" or 1/4" and feed your new hose down through a hole and out of the car near the wheel arch.

    My sizing is sketchy as I've not looked at hoses for a few months, but really within reason, most sizes should be fine.

    I have a 280z tank which has an extra pipe, but from memory I just blanked these off.
     
    Paul_S likes this.
  7. Paul_S

    Paul_S
    Z Club Member

    I've been doing some more digging and found out some useful information.

    Firstly, to answer my question in the first post, it looks like there is no issue blanking off the 2 breathers rather than put a pipe between them because the early US (and probably all the UK) tanks had no breathers there at all:

    [​IMG]

    Here are the dimensions for all the pipes on the tank:

    [​IMG]

    Which tie into the dimensions on the header tank:

    [​IMG]

    So the only issue I have now is that the replacement hose needs to be 17mm ID at the tank end but 19mm ID at the filler neck end. It doesn't really matter what the ID of the hose that comes off the T and goes through the floor is, but the current hose that goes through the hole in the floor is 8mm ID so it can't be much different than that or it won't go through.

    Finding 17mm hose is proving to be tricky and I'm sure I won't find a T with ends of 19mm, 17mm and 8mm so I'm going to have a bit of a job sourcing the parts. I'm sure something can be rigged up though.

    These were my sources (so feel free to validate them or otherwise):

    https://www.classiczcars.com/forums/topic/54065-1972-240z-gas-tank-hoses-available-and-where/
    http://woodworkerb.com/home/datsun-240z-rebuild/240z-fuel-tank/
    https://www.classiczcars.com/forums/topic/49031-whats-that-smell-exhaust-fumes/

    Any help or advice sourcing parts would be appreciated :)
     
    tyroguru likes this.
  8. Makesy

    Makesy
    Z Club Member

    Hi Paul,

    I sourced some fat 19mm hose but in honesty it's not necessary and an absolute PITA to thread through the metalwork!

    You can find suitable brass or plastic step downs / Ts on eBay.

    Blank all other unnecessary breathers and you will be fine.

    Alex
     
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  9. Paul_S

    Paul_S
    Z Club Member

    Thanks mate. I'll have a search :)
     
  10. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

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  11. Paul_S

    Paul_S
    Z Club Member

    Thanks for the link :)

    My car doesn't have a T connector but it does have the US header tank and some old leaking hoses so I can't fill it above 3/4 on the guage.

    When I get round to sourcing the parts and putting it together over winter I'll be sure to post up explaining the process.
     
  12. moggy240

    moggy240 INSURANCE VALUATIONS OFFICER Staff Member Moderator

    I found this one, it's 17mm each end and 8mm in the middle, the proper one is 19mm 17mm and 10mm in the middle.
     

    Attached Files:

    Paul_S likes this.
  13. Paul_S

    Paul_S
    Z Club Member

    Cool! Where did you find it?
     
  14. Paul_S

    Paul_S
    Z Club Member

    OK, I've had a look around and this is what I've found:

    Fuel hose 19mm x0.2m & 16mm x1m (from here) and 8mm x1m (from here). 16mm / 8mm / 16mm T (from here). 19mm to 16mm reducer (from here) and probably a couple of 16mm elbows from the same place to make up the looped end - it sounds easier than using a spring to loop it.

    I would need to struggle the 16mm pipe on the 17mm breather but with a little bit of work I guess it wouldn't be too hard.
     
  15. jonbills

    jonbills
    ZClub Administrator
    Staff Member Moderator

    A couple of mins in boiling water and it'll go over easy.
     
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  16. Graeme - CZ

    Graeme - CZ
    Z Club Member

    Hi folks,

    I'm about to set to and to this conversion as my pipes need replaced. @Paul_S Thanks for your list. Very helpful.

    I've got a question about blanking off some of the now not used pipes coming off the tank. I believe I have 2 to blank off, what looks like one 8mm one and one either 16mm or 19mm one. Any tips on a product I can use to blank these off?

    Cheers, Graeme
     
    Paul_S likes this.
  17. Makesy

    Makesy
    Z Club Member

    I just used some leftover hose with a bolt pushed into one end and jubilee clips to told it all in place.

    Redneck? Yes.

    Suitable? Most certainly :)
     
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