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F Head Intake Valve Seal Question

Discussion in 'Early CJ5 and CJ6 Tech' started by jeeper50, Sep 7, 2020.

  1. jeeper50

    jeeper50 jeeps 'till I die

    My F head recently began burning oil more and more, as evidenced by the blue smoke after start up, Motor was overhauled back in '09 and doesn't have more than 5K miles on it since. Any ideas for easy o ring replacement on the valves?
     
  2. 73 cj5

    73 cj5 Not ready for the junkyard yet

    Next time the head is off have someone cut the guide bosses for a Positive wiping seal. Does it smoke during declaration?

    One way to replace them is by adding compressed air to the cylinders and hope the valve doesn't fall into the cylinder.
     
    Fireball and jeeper50 like this.
  3. jeeper50

    jeeper50 jeeps 'till I die

    Unfortunately the Fhead does not have any cast bosses only the valve guide supports the intake valve train, So I guess I'll pull the head to remove the old oring valve and install new ones, guessed I missed those during my overhaul. I watched metalshapers' video to clarify the stack up of the valve and new oring seal.
     
  4. Keys5a

    Keys5a Sponsor

    You can replace those seals easily without pulling the head, as suggested in post #2. Just use a spark plug adapter/air tool quick disconnect hooked up to an air compressor. At TDC, the air will hold the valve closed so you can remove the keeper/spring to replace the seals.
    -Donny
     
    jeepstar likes this.
  5. Oldriginal86

    Oldriginal86 Member

    I’ve heard of folks using a length of small diameter rope stuffed into the cylinder to keep the valve up in place. Never tried it, used air pressure.
     
  6. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Yes, I have heard of that too. Hold the valves up with rope that you can retrieve from the cylinder. What could go wrong? (Not being facetious!)