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Intake Valve Seal And Air Leak Question

Discussion in 'Early CJ-5 and CJ-6 Tech' started by davet, Jul 8, 2019.

  1. Jul 8, 2019
    davet

    davet Member

    Andover, MN
    Joined:
    Jul 30, 2003
    Messages:
    162
    I decided to try and tackle valve seals tonight. I've never done this myself before and my brother gave me all the tools I needed. I've had some exhaust smoking and the head was done about 20 yrs ago. Please let me know if anything below relates to the smoking and anything else you can advise on.

    --I put air to #1 cylinder and get a moderate leak out of cyl #3. Plugging the spark plug hole stops that leak.

    -- Still air passing through somewhere. Definitely not oil filler tube, other plug holes or radiator. Sounds like coming right from #1 cyl somewhere. I should've put my stethoscope on the exhaust manifold. Maybe it's passing by the exhaust valve and I'm hearing some of it through #3 cyl plug hole. Does that make sense? No air leaking at #2 spark plug hole though.

    --Capping the carb has no effect on this additional air leak. No fuel coming out of carb anywhere with air on Cyl #1.

    --Took spring off #1 cyl and the o-ring seal was where it should be and did not appear distorted or cracked. It was still flexible.

    --Putting it back together is more difficult. I've got the same style o-ring seals that came out (Fel-Pro #407). Dropped spring into place and the retainer. Then, placed seal over valve and got it to lay in the retainer. The shoulder inside the retainer is not very pronounced. If the spring shifts much while compressing it the o-ring can drop down off the shoulder and get cocked on the valve stem.

    --Are the Sealed Power design seals easier to work with?

    Thanks.
     
  2. Jul 8, 2019
    Walt Couch

    Walt Couch sidehill Cordele, Ga. Sponsor 2019 Sponsor

    cordele, Ga.
    Joined:
    Mar 29, 2007
    Messages:
    5,379
    Bring NO#3 to TDC on compression and inject air. If you get air in NO#1 cylinder you have a blown head gasket.
     
  3. Jul 8, 2019
    davet

    davet Member

    Andover, MN
    Joined:
    Jul 30, 2003
    Messages:
    162
    Thanks. I’ll try that
     
  4. Jul 13, 2019
    davet

    davet Member

    Andover, MN
    Joined:
    Jul 30, 2003
    Messages:
    162
    Went through all cylinders. I get a small amount of air leaking out tailpipe in all cyl. Various leaks from oil filler tube and carb also.
    I’ll put it back together and do a compression test to see what that looks like dry and with some oil.
    Got some prices for machine work and looks like I’ll just drive it for the summer and maybe get back at in the winter when it sits in the garage. Got another set of leaf springs getting modified and would like to use them this summer.
    Local machine shop that does all the motor work for the local Willy’s ‘old timer’ found me some umbrella type intake valve seals for the f-head.
    Can I install those along with the o-ring type?
    Thanks all.
     
    Last edited: Jul 13, 2019
  5. Jul 18, 2019
    davet

    davet Member

    Andover, MN
    Joined:
    Jul 30, 2003
    Messages:
    162
    Trying to fit umbrella valve seals.
    Anybody know how far an intake valve drops when fully open?
     

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