Valve stem seal replacement on ’93-’98 toyota supra turbo

Valve Stem Seal Replacement on ’93-’98 Toyota Supra
Turbo


by
Phil Panas


Old & New
Seals
Disclaimer: Attempt this job only at your own
risk.  Potential risks of this job include (but are not limited
to):

  • Dropping valves into cylinders
  • Dropping keepers into oil passages (which may
    require head removal), (or loosing them if they go flying across your
    garage)
  • Scratching and/or bending valves
  • Putting the wrong valve stem seal onto the wrong
    side (eg. intake seal onto exhaust side)…they’re two different part
    numbers
  • Not getting the seal properly seated – it will then
    slip up onto the valve stem and oil will leak (this will be like having
    no seal in at all)
  • Misshaping the seal when it is pushed into place –
    this will also cause a leak
  • Forcing or tapping the seal down too hard. 
    The metal shell of the keeper, forced down too hard onto the top of the
    valve guide, can partially or completely cut through the rubber section
    at the top of the valve stem seal

Tools Required:

Seal Removal
Pliers
Keeper
Tools:

  • Pictured to the right is a hand-made pair of
    keeper tools.  The tool on the left in the picture is for
    keeper insertion and can be either made, or purchased (see
    below). 
  • The tool on the right is for keeper removal,
    and is relatively easy to fabricate.  Simply use a
    high-density plastic (preferred) or a hardwood dowel, drill a big
    hole in the end, a smaller hole inside that one, and epoxy a
    strong magnet into the small hole. 
    Here is a link
    where I believe you can obtain some of the UHD/UHMD Plastic
    Rod/Dowel that is used in the valve stem seal tools in the
    picture.  A 1″ dowel/rod should work well.
  • The removal tool’s inner diameter should be
    as large as possible, while still keeping a strong shell on the
    outside to take the force. I’d estimate that the inner ‘hole’
    should be about 5/8″, which would allow for a 3/16″ wall to push
    the retainer down with. If you wanted to be really safe, drill a
    1/2″ hole and then the wall will be a full 1/4″ thick – the
    problem is there might not be enough clearance for the keepers to
    pop out of the valve with a 1/2″ hole…
  • Place the magnet about 1/2″ to 3/4″ deep. The
    depth has to be enough so that the magnet never hits the top of
    the valve, no matter how much you compress the valve spring while
    pushing on the retainer. The magnet also can’t be too deep or the
    magnet will not be strong enough to ‘catch’ the keepers most of
    the time

 

  • This Snap-On
    tool
    (pictured on the right) will work for keeper insertion,
    but only if it is modified so that it doesn’t scratch the bucket
    bores
  • This tool is modified by taking a large file
    and filing the knurl on the end completely smooth so that it
    doesn’t scratch the bucket bores


Keeper Removal
Tool (on right)

Keeper Insertion
Tool

Other Stuff:

  • New keepers, gaskets, etc. from Toyota

    • Exhaust: 90913-02088
    • Intake: 90913-02106
    • I’d recommend you replace the camshaft seals, the
      valve cover seals, and possibly the pcv, pcv hoses and valve cover
      bolt seal washers.  You also might want to change your plugs
      since they have to come out anyway.
  • Redline Assembly
    Lube
  • Toyota Form in Place Gasket material (FIPG)
  • If this is your first time, consider ordering a few
    extra seals of each type, and a few extra keepers (just in case)
  • Lots and lots of patience, and at least 10 hours
    nonstop
Prep:

  • Remove the two engine lift hooks from the
    head
  • Remove cam covers, camshafts, and spark plugs
    according to Toyota Supra Repair Manual
  • Note that you should measure the shim
    clearance before removing the cams.  If any are out of spec,
    they can be replaced at the end of the install
  • Remove all of the buckets and shims, keeping
    them in order (do not mix them up – this is
    critical!)


Step1:

  • Set the piston in cylinder#1 to BDC (Bottom
    Dead Center).  You can put the aluminum rod into the
    sparkplug hole and watch it while another person turns the
    crankshaft with a 22mm socket & ratchet to find BDC. 
    Mark the depth of BDC on the aluminum rod for reference on the
    other cylinders.
  • Using the other aluminum rod (sharpening the
    tip a bit helps), stuff all 8′ of the nylon rope into the cylinder
    (as in the pic below), and then move the piston towards TDC (top
    dead center), until you feel the piston firmly compressing the
    rope against the head & the bottom of the valves.  The
    pic below shows cylinder #2 with the rope, but I’d recommend you
    start with #1, just to stay organized.
  • Note: In the diagrams, we’re working on the
    valve circled in yellow in the pic on the right

 

Step 2:

  • Put the Keeper Removal tool on top of the
    retainer, and give the top of the tool a light blow with the big
    hammer.  The keepers will pop right out and stick to the
    magnet inside of the tool, as shown

Step3:

  • Remove the spring&retainer, reach in with
    the seal removal pliers and remove the seal.  Again, don’t
    try this with needle-nose pliers: when (not if) the pliers slip
    off the seal, they will scratch the valve stem.  The
    intake-side seals are often on so hard that they are very, very
    difficult to remove, even with these special
    pliers
    .
  • After removing the seal, inspect the base of
    where the seal was installed.  Often (especially on the
    exhaust side), a ring of rubber from inside the old seal will
    break off, and you’ll need to use your aluminum rod to remove this
    debris.

Step 4;

  • Coat the inside of the new valve stem seal
    with
    Redline
    assembly lube
    , and with your fingers or the seal pliers, place
    the new valve stem seal (make sure you put intake seals onto the
    intake side and exhaust seals onto the exhaust side) over the top
    of the valve stem, onto the top of the valve guide (as in the pic
    to the right).  Gently, and then gradually more firmly push
    the seal down with 10mm deep socket until it kind of
    ‘double-clicks’ into place.  Be sure you’re pushing the seal
    down as squarely/centered as possible so the seal seats properly
    and so the valve stem doesn’t get scratched.

Step 5:

  • With the deep 10mm socket over the valve
    stem, centered on the top of the seal.  Give two light, but
    firm blows with the dead-blow hammer.  Careful – if you hit
    too hard, it will misshape the valve stem seal, or the metal shell
    of the seal will cut completely through the seal’s rubber, ruining
    the seal.  On the other hand, if you don’t hit firmly enough,
    the seal might not be properly seated.  I estimate about a 2″
    ‘windup’ and a relatively firm (but not hard) hit.
  • As you might guess, this step is the most
    critical step in ensuring your new seals will perform
    properly.  If you suspect a seal may have gotten bent, or the
    rubber was damaged in this step, I’d advise to replace the seal
    now rather than hoping it will work after reassembly.

Step 6:

  • Replace the spring and retainer, and then
    carefully place the 2
    keepers into the retainer, above the top of the valve stem, as in
    the pic below.  Be sure not to drop the keepers – they can
    fall into inaccessible crevices, which may require head and/or oil
    pan removal.
  • Push the keeper insertion tool’s tip in
    between the keepers, and push down straight and fairly hard, and
    the keepers will pop into place.  NB: This technique takes
    some practice to perfect. Also, do not hit the keeper insertion
    tool with a hammer – your keepers will go flying across your
    garage or into your engine.
  • If only one keeper gets stuck in and the
    other is out, you’ll have to use the keeper removal tool to remove
    the one keeper and start this step over.
  • After the keepers look like they have been
    seated properly, give the top of the valve/retainer a tap with the
    plastic hammer to be sure they are locked in place.
     

Step 7:

  • Repeat steps 2 through 6 on the other 3 valves in
    the 1st cylinder, ensuring you use the intake-side valve stem seals on
    the intake side, and the exhaust seals on the exhaust side.
  • Move the cylinder back  to BDC, and remove the
    rope.

Step 8:

  • Repeat steps 1-7 for the next 5 cylinders (and the
    other 20 valves in those cylinders)

Finish:

  • Replace all of the buckets and shims, in the same
    locations they were removed from.
  • Replace camshafts and check shim clearances
    according to Toyota Supra Repair Manual.
  • Replace the camshaft seals using
    Redline assembly
    lube
    on the inside edge of the seals and FIPG on the outside edge of
    the seals.
  • Replace cam covers using new gaskets and preferably
    new sealing washers, along with the sparkplugs, coil packs, etc., all
    according to Toyota Supra Repair Manual.
  • Replace the two engine lift hooks

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