Replacing oil seals in heads

Discussion in 'Cams, Heads and Valve Trains' started by chromebumpers, Jul 16, 2018.

  1. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    Ok, I have some burning oil issues from disintegrated valve stem seals. I need to inject air pressure into the cylinders to hold the valves up while I remove the 2 part retainer and seal. There must be a tool to hold the air pressure and let me do so hands free.
     
  2. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    You use the hose from an engine compression tester set, remove the Schrader Valve 1st.

    I have used 6 feet of Nylon 1/4" inch Rope instead of compressed air.
    Remove all spark plugs.
    Bring the cylinder down to Bottom Dead Center.
    Feed in all 6 feet of rope but maybe 6 inches hanging out.
    Turn the engine normal rotation and keep going till it stops turning.
    Able to remove the Valve Locks and Valve spring retainers.
    Did it that way on my Olds 425 in the 63 Gp.
    I had no big air compressor 2 years ago.
    I have a nice gas engine powered air compressor now.
     
    Strictly Attitude likes this.
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    [​IMG]
    If the valve springs are to be removed with the heads still on the car,

    the last thing you want is too remove a valve spring and have the valve to drop into the cylinder,
    if you use air the crank tends to want to spin the crank to BDC, youll want to verify TDC ,
    and make sure the flywheels temporarily prevented from turning from that the TDC position,
    Ive used both methods both work,you can put 6 ft of rope in the cylinder while its in BDC then turn it to TDC, Ive used both with zero issues,
    If you use the compressor youll want to keep it at 120 psi and constantly feeding pressurized air to keep the valves held in place,
    and theres a small chance the compressor pushes enough moisture to allow water to accumulate in the cylinders,
    so be sure you spin the engine with the starter with the spark plugs removed several times before you re-install plugs.
    if you use the rope, theres a very low chance that the rope will tangle and form a knot that makes removal difficult,
    in either case be sure the pistons locked at tdc,
    before removing the valve springs, on each cylinder.
     
    Last edited: Jul 16, 2018
  4. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    The rope sounds easier, I’ll go that way. Thanks guys.
     
  5. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Get a vid soon of how too
     
  6. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

  7. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

  8. Strictly Attitude

    Strictly Attitude solid fixture here in the forum

    Did it with air using compressor and hose from compression checker. Had to beat with rubber mallet to get retainers to let caps free. Did twice to change then break in Isky cam. Remove center spring then reinsatall after break in.
     
  9. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    all thats rather commonly done, but the important part...
    did the cam and lifters lap in correctly?
    were the new oil seals installed correctly and did everything work out well?
     
  10. Strictly Attitude

    Strictly Attitude solid fixture here in the forum

    It did on my project worked perfect
     
  11. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    So far, so good with mine also.
     
    Strictly Attitude likes this.
  12. stepside

    stepside Well-Known Member

    IMG_20180819_205840.jpg IMG_20180819_205902.jpg I fabricated valve spring tool for bbc,works well when space is limited
    [​IMG]
    [​IMG]
     
    Strictly Attitude likes this.
  13. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    Now that's what I like to see.
     

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