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
  • 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!)

  • 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

  • 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)


  • 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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