secondary carb diaphragm

Discussion in '60-Series Wagons' started by beaufort-fj60, Feb 18, 2008.

  1. beaufort-fj60

    beaufort-fj60

    Messages:
    5,070
    I'm changing out the secondary carb diaphragm. Sor has one for $45, napa $14, and all kinds of prices in-between those. Has anyone replaced the rubber in the old diaphragm? That couldn't be more that five cents worth of rubber.
    crisp.JPG crisp3.JPG c4.JPG
  2. Great photos!

    I know there are rebuilders who repair rather than replace the assemblies. But they usually are working on obsolete stuff. $14 from Napa seems like a great value. While it's still available that seems like a fair exchange. To me.

    Rick
  3. beaufort-fj60

    beaufort-fj60

    Messages:
    5,070
    $14 is cheap, I'll probably go with the Napa one. Just wondering if any other cheap-skates out there tried to rebuild it. :D
  4. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

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    $14 is cheap.

    Amusing repairs:
    Seen some diaphragms that were skinned w/ a layer of RTV snot.
    Seen some Holley diaphragms w/ Aisan link brazed on to the chopped holley link.
  5. beaufort-fj60

    beaufort-fj60

    Messages:
    5,070
    :whoops:$21.74 for part/tax/shipping.. Only problem with the Napa part is; the guy at the store said no stores have the part and it is ordered from the "factory". That either means I'm not going to get it or it will take awhile. wild guess



    are most of the diaphragms you see in rebuilds old, torn, and cracked? The one in the above pics sounds like a piece of paper its so dried out.
    Last edited: Feb 18, 2008
  6. Willius

    Willius

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    101
    Location:
    West Seattle, WA
    Click Here: Carburetors

    I replaced my diaphragm with the one that came in this kit. If you haven't done a tune recently, do one, otherwise it'd be good to have some spare tune parts around. Mine arrived in about a week.
  7. beaufort-fj60

    beaufort-fj60

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    5,070
    CCOT is a little to overpriced for me...
  8. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

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    Yes, they are usually bad after ~20 years.

    I've got the diaphragm in stock for about NAPA price. Email me for info.
  9. beaufort-fj60

    beaufort-fj60

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    5,070
    I ordered the Napa one a few hours ago. :doh:
  10. Gargoyle

    Gargoyle

    Messages:
    3
    I have replaced the ribber in the diaphragm on several occasions and have learned the hard way. Make sure not to tighten the screws to tight - this will cause warping and leaking. Also placing the bottom of the diaphragm over the rod and then push the rod up so that the spring is compressed before tightening the screws will prevent the rubber from being stretched or wrinkled causing leaks. I have found that even the tiniest leak will render the diaphragm useless. Frankly, I would gladly pay $15- $20 for a new leak free diaphragm. I did not know they were for sale - Thanks!!

    -Gargoyle
  11. Marc311

    Marc311

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    937
    Location:
    Northern Virginia
    So, what is the function of the carb diaphragm?

  12. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

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    Marc, the secondary diaphragm has vacuum applied to one side of it by passages in the carb. The vacuum overcomes a closer spring and actually pulls open the second barrel on the carb.

    When the rubber is cracked and leaky, vacuum cannot build up behind it, so the secondary never opens.

    Sadly, this $14 failure has probably lead to several V8 swaps. (nothing wrong w/ a V8, just an extreme solution for a $14 problem).
  13. beaufort-fj60

    beaufort-fj60

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    5,070

    Can you put in a "weaker" closer spring to tap into the secondary a little earlier?
  14. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

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    Yes. There are different Aisan springs available. Plus the Holley springs will fit, though they look a little different.
  15. beaufort-fj60

    beaufort-fj60

    Messages:
    5,070
    is this the spring inside of the diaphragm? .. never mind... I got it.

    Vac pulls, overcomes the spring (compresses it inside the diaphragm), rod connected to diaphragm pulls on the end of the secondary butterfly rod, rod turns, secondary opens.
    Last edited: Feb 21, 2008
  16. kranky al

    kranky al

    Messages:
    3
    how hard is it to rebuild a carb - there is a guy wrecking a 60 and i was thinking of buying his old carb and rebuilding it - im no mechanic - but i like playing around with fiddly **** and thought i could rebuild his and when finished swap it for my old had it carb - and worst comes to worst - if i cant put it back together - just hand it over to competent authority


    thoughts?
  17. its easy I re-built mine in the same day that included taking it off and re-installing it all back on the truck. just a buncha little parts but the re-build kit should come with a picture w/ numbers to show u where everything goes in case you forget.
  18. JLH911

    JLH911

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    Could/Would this cause rough idle?
  19. beaufort-fj60

    beaufort-fj60

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    Like cruisinfj60 said, the carb rebuild kit comes with a diagram. The factory service manual has a very nice write up on the whole carb rebuild.
  20. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

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    Location:
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    No, not in the least. The entire sec.diaphragm assembly could be left off the carb and it would start & idle fine.

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