Vacuum line sizes | The Z Club of Great Britain
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Vacuum line sizes

Discussion in 'S130 (280ZX)' started by Aiden J, Jul 31, 2020.

  1. Aiden J

    Aiden J
    Z Club Member


    I’m just in the process of renewing a few things before I get the car running.
    Can anyone tell me the size of the vacuum lines needed? A lot of them are split from the California heat / age

    Fuel line sizing as well?

    1979 280zx

    And a final question. Is there a way to prime the oil pump manually without cranking the engine? Not sure how dry it is in there. I’ve taken the dizzy off; not sure the best method to turn the spindle round
  2. Bazzateer

    Z Club Member

    No idea about vac/fuel lines but a ratchet spanner and socket on the crank should prime the pump without causing problems.

    Then spin it up on the starter with the ignition disconnected and check for pressure on the dash gauge.
  3. Turn & Burn

    Turn & Burn
    Z Club Member

    You can’t simply spin the oil pump drive shaft as it’s driven of the crank on a sort of helical gear.
    You need to drop the bottom off the oil pump, and drop the shaft out. Refit the pump base. Using a long shaft such as a screwdriver in a drill down the dizzy hole u can then prime the whole engine in seconds. The drill needs to run in reverse. Take the rocker off and you will see oil spray out of the cam / spray bar. Drop the bottom off the pump when ur done and refit the spindle. It doesn’t empty the whole pump as you do this.
    This sounds long winded but it’s done in 10mins and very effective at fully priming the motor.
    hallie likes this.
  4. Pondo

    Z Club Member

    Bit like this?
    Turn & Burn likes this.
  5. jonbills

    ZClub Administrator

    thats a lot of faffing about! I'd just take the spark plugs out and cam cover off, poor some oil on the cam and crank it.
    AliK likes this.
  6. Turn & Burn

    Turn & Burn
    Z Club Member

    It is 10mins of faff, but it answers the original question ‘is there a way to prime the engine without cranking it?’

    Sent from my iPhone using Tapatalk
    jonbills likes this.
  7. AliK

    Z Club Member
    Staff Member Moderator

    Having just re-done my fuel lines on a ‘77 260z (which is a close relation to the 280 in many ways) it was 8mm ID both supply and return. I used single piece aluminium pipes from the tank to the fuel filter / fuel rail.

    That way the total amount of rubber involved is less than 0.5 metres. The “join” half way on the supply was allowing for electric fuel pump connections (but for now I decided against it, so there’s a bit of rubber there).


    If I did this job again, I would use an “AN” joint or two before the firewall as it is a total pain handling a 4m long pipe with a tonne of kinks etc.

    The vac lines are NLA so you have to get the kinks right. I attempted this with 10mm copper pipe inside rubber hose and it’s a ball ache but doable. Others have heated the rubber. As for sizes, I can’t be sure but just measure the one way valve (on the firewall) diameter.

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