Jump to content
The mkiv Supra Owners Club

How To: Valve Stem Seal Replacement


TLicense
 Share

Recommended Posts

  • Replies 160
  • Created
  • Last Reply

Top Posters In This Topic

This will be a great reference for the future Tony. Thanks for all the photo detail, they must be adding quite a bit of time to the job.

 

 

 

Just for the archive records, can you confirm which type of kitchen towel should be used. I find Bounty the only one man enough for the job.:innocent:

 

 

 

 

(Sorry :taped: I am sure mods can take this out later.)

Link to comment
Share on other sites

 

(Sorry :taped: I am sure mods can take this out later.)

 

I will once Mawby sorts out my permissions :D

 

Tony, you said this:

"To find approximately bottom dead centre (BDC) I gently put a long (maybe about 9 inches or more) screw driver down the spark plug hole, and then turned the camshaft untill the screwdriver stopped moving down and started to move back upwards."

 

Did you mean crankshaft?

 

-Ian

Link to comment
Share on other sites

Seal in pliers:-

image

 

image

 

image

 

image

 

The seal will quite possibly split as you remove it. This usually means it leaves a small rubber ring around the valve stem, you'll need to fish this out:-

 

image

 

image

 

If you look into the bucket or lifter bore now, it should look something like this:-

 

image

Link to comment
Share on other sites

So now you'll be ready to fit the new seal. Make sure you fit the correct one. They are different inlet to exhaust. The inlet ones have a bronze finish to the outside of the seal, whereas the exhaust one has a silver/grey finish.

 

I dipped the seal into clean engine oil (assembly lube would be better) and then positioned it over the tip of the valve stem. Make sure it goes on nice and square:-

 

image

 

I then used the valve seal tool to push the seal down the valve stem. When it gets to the bottom it should double click into place. If you've loaded it with lots of oil/lube it will more than likely "squelch". Give it a gentle tug with the pliers to make sure it's locked into place.

 

Now it's worth making sure that there's no play in the valve. Take the stem and see if it moves upwards or downwards. If there's more than a couple of mm of play, it means the rope has been compacted down by the lock/retainer removal process. To fix, try moving the crankshaft towards TDC again. If this doesn't work you'll need someone to hold the valve in place whilst you first of all move the piston by rotating the crankshaft back from TDC. Then pull say about 9" of rope out of the spark plug hole. Then re-insert the rope, but using something about the size of a knitting needle, try to push it in the direction of the valve you are working on. Whilst doing this the person holding the valve should not let go. If they do, it will more than likely mean having to remove the head to get the valve back. With the rope back in position rotate the crankshaft back to TDC untill you feel the piston hitting the rope again. Hopefully the rope should be under the valve head now, and the valve will not move. If it does try this again untill it doesn't. (After doing all 24 valves I never had to try it again!)

 

Next take the valve spring. Give it a check over to make sure it's dust/dirt free. If not give it a clean over with a paper towel. Fit it back over the valve stem. Make sure it's seated correctly at the bottom:-

 

image

 

Next place the retainer over the spring. Again make sure it's seated square:-

 

image

 

Place the valve locks into the hole in the valve retainer. To re-insert the locks I found I could semi insert them by pushing on them with my thumbs. This helped to locate them:-

 

image

 

Then using the valve tool, I placed the tip between the locks, squared the tool up to the retainer and gave it all a good push down the axis of the valve. 50% of the time it worked straight away and the locks clicked into place. I used a kind of pumping up and down motion. After 3-4 "pumps" I checked to make sure the retaner was locked in. Sometimes 1 of the locks would drop in and the other wouldn't. Like this:-

 

image

 

If it does this you need to remove them again, and try to fit them again untill they both drop in evenly.

 

To make sure they are fitted correctly, push down on the retainer untill the spring compresses a little. If fitted correctly the retainer and locks will stay in place. If they move at all, remove the locks using the valve tool, and re-fit them.

 

It's now time to re-fit the bucket. Again make sure it's clean. It needs to drop into the bore squarely. It should be an easy fit, and won't need much pressure at all to push it down. If you need to force it, it's not sitting square, so lift it back out and try again.

 

Then onto the next one......

Link to comment
Share on other sites

Right then, where did I get to...

 

Ahh so you should now have the valve locks in place for the first valve and it should look something like this:-

 

image

 

So now you need to repeat the procedure for the remaining 23 valves.

 

As you're going along I stongly advise that you place some paper towel either side of the valve you're working on to stop the small valve locks dropping into the depth's of the engine.

 

Also as you go along you may find you run into some problems with things getting in the way like engine hooks:-

 

image

 

It's only two bolts to undo each one, and it'll make the job much easier. Engine hook removed:-

 

image

 

Another item that can get into the way is the VSV for the intake air control valve (1 bolt and two hoses) and also the intake air conrtol valve actuator:-

 

image

 

Which has two phillips head screws. Be careful when undoing these as they're prone to rounding off:-

 

image

 

So once you've done all 24 valves it's time to start putting the whole lot back together again. But before you do, it's the ideal opportunity to take some tiem to make sure everything is in shape. Give each valve a good shove to make sure the valve locks are in place. Check that you can rotate each bucket in it's place albout the axis of the valve stem. It should move fairly easily. If not take the bucket and shim off and try re-fitting it. I had one that for some reason was a little stiff. I removed and then re-fitted it and it was a lot better. VERY IMPORTANTLY Make sure everything is clean, and that you've accounted for all nuts bolts and tools. You don't want to leave anything in there that shouldn't be there!

 

OK so re-assembly should be fairly easy now that you've got this far.

 

First of all re-fit the camsshafts. You need to apply a some engine oil to the thrust face of each camshaft. (This is the face that pushes up against the bearing caps along the axis of the shaft)

You need to install them in a vertain position. There's a pin on the end (knock pin) on the end of each camshaft to help do this.

Install them to start with, witht the inlet cam, with the knock pin at the 3 oclock position (These pics were taken after I'd fitted the no.1 bearing caps so ignore them):-

 

image

 

and the exhaust cam with the knock pin at the 11 oclock position:-

 

image

 

Now fit the no.3 and no.7 bearing caps, and tighten the bolts untill the caps are snug against the head:-

 

image

Link to comment
Share on other sites

Now fit the oil seals to the end of the camshafts. Apply a small amount of light grease to the inside of the seal to help the seal slide into place:-

 

image

 

Next fit the number 1 bearing caps. Put some of the sealant onto the mating face of the bearing/cylinder head. After taking this pic I added a little more than this as I didn't feel it would be enough:-

 

image

 

To give you some idea, when I tightened the bearing cap, this amount squelched out from the mating face:-

 

image

 

Now fit and tighten to 20Nm (14ft/lb) the remaining bearing caps in the following order:-

 

5-1-3-4-2-6-7

 

image

 

Now here's the trick bit.

 

You now need to align the knock pins to the 12 oclock position. Use the hexagon section half way down the camshaft and and adjustable spanner to turn the camshafts clockwise untill they're at the 12 oclock poisiton:-

 

image

 

Now undo and then re-torque to 20Nm the following bearing caps bolts:-

 

Inlet: 1-2-5

 

Exhaust: 1-2-6.

 

Now rotate the camshafts again clockwise to the 4oclock position:-

 

image

 

No undo and then retorque to 20Nm the following bearing cap bolts:-

 

Inlet: 4-6

 

Exhaust 4-7

 

Now rotate again, clockwise, to the 8 oclock position:-

 

image

 

Undo and then re-torque to 20Nm bearing caps:-

 

Inlet 3-7

 

Exhaust: 3-5.

 

If at any point you find you can't move the camshaft around, it probably means you've got a bucket/shim that is stickling in place. You need to remove the camshaft using the same order of bearing cap removal as you did when removing the cams the first time around. Check all the buckets are moving freely and then go back to the camshaft installation and repeat the installation procedure.

 

Now re-check the valve shim clearances. I found mine were a little tighter than before but still within the same tolerances as when stripping the cams out.

Link to comment
Share on other sites

So hopefully that will be the camshafts fitted.

 

Next fit the no.4 timing belt cover, make sure the wiring loom is behind the cover when you fit it, it's too tight to lift it over once the cover's fitted. Trust me! Make sure all 4 bolts that you removed get put back. (They should be torques to 8.8Nm but I defie anyone to get in there with a torque driver!):-

 

image

 

Now fit the camshaft gears. Why not put them back on in the order they came off? To help fit them use a spanner at the hexagon section (or mole grips in my case!) to hold the camshaft in place. Use a cloth to stop the spanner from "dinking" the head. They need to be tightened to 79Nm (59ftlb)

 

image

 

Now's a good time to set-up the timing.

 

What you need to do is to align the camgears with the timing marks on the no.4 timing belt cover:-

 

image

 

image

 

You then need to set the crank-shaft pulley to the 0 timing mark, with the no.1 cylinder at top dead centre.

To do this gently place the long screw driver into the plug hole of the no.1 cylinder, then turn the cranksshaft untill the timing mark lines up with the 0. NOW be careful, there's two timing marks on the pulley. (As I found out after a lot of head scratching later!) if you're turning the crankshaft clockwise it's the second timing mark that you want to use.

 

You can just make out the yellow timing mark on this shot (It's really difficult to get a good shot of this!)

 

image

Link to comment
Share on other sites

Now fit the cambelt over the camgears. To do this I fitted the belt to the inlet side first and then onto the exhaust camgear. This keeps the cambelt nice and tight and stops your timing from slipping when you put the tensioner on which is the next step.

 

To fit the tensioner, you need to place remove the rubber dust boot from the end, then place it in a vice. You then need to clamp the vice up untill the hole in spigot in the middle lines up with the hole on the ring around the outside. Then stick a 1.5mm or equivalent allen key into both holes like this:-

 

image

 

Then refit the dust boot:-

 

image

 

Next fit the tensioner with the allen key in place. I found it easiest to lift the tensioner into place using a socket with and extension fitted to the bolt that fits into the tensioner that is closest to the front of the car when the tensioner is fitted. It's a bit difficult to explain, but after 20 mins of trying to fit the damned thing I found this way to be easiest. Unfortunately I couldn't get any shots of this (I couldn't focus that close!)

Once the tensioner is fitted, using a pair of pliers reach up and pull the allen key out of it's place.

Now go and check the timing again. Hopefully it should still be spot on. If not remove the tensioner again, and the timing belt from the camgears and try again untill it's timed perfectly. Once done remove the big screwdriver from no.1 cylinder.

 

Next re-fit the no2 timing belt cover using the 3 bolts and a 5mm allen key:-

 

image

 

With that done you can now go ahead and fit the cam-covers.

 

Once again use the sealant where the cam cover goes over the no.1 bearing caps. Make sure you remember to place the washers under the nuts bolts and tighten them to 5.4Nm

 

image

 

Next fit the spark plugs, and then the coil packs. Make sure they go back into the same position and in the same orientation as they came out.

 

Re connect the 6 plugs to the coil packs, and also the 2 VSV's that connect to the exhaust side of the loom.

 

Next re-fit the two breather pipes accross the centre of the cam covers and the two pipes on the sides.

 

Now's the time to refit the idle air control valve pipe. make sure all the tubes are fully on. (I found it easiest to thread it in via the left hand side, right next to the idle air control valve.

 

Now refit the spark plug cover and all the bolts again using a 5mm allen key.

 

Refit the accelerator cable mount and also refit the accelerator cables. Make sure there's a small amount of play on the cable.

 

So that's it, you're pretty much done. Before you rush in though, make sure everything is tidy, and that all the electrical connectors and pipes that you have removed and refitted are correctly seated and pushed on.

 

So that's it go ahead and start her up and she should purrr like a smokless kitten!!

 

If you have any questions/suggestions feel free to pm me or add them to the bottom of this thread.

 

Best of luck with it! :thumbs:

Link to comment
Share on other sites

How much will you charge to do mine when the time comes Tony? :)

 

LOL well because I was taking my time, and as you can tell, taking lots of shots with the camera (There's quite a few that didn't make it into this thread!) it took me close to 20 hours to do the job. I should think if I were to do the job again it would probably take me about 10-15 hours. So I can see how pofessional mechanics who are charging £50-60/hour can charge £600 for the job, then there's the price of the parts on-top.

Personally I wouldn't charge anyone beyond £300 plus parts, at the end of the day it's just spannering and being methodical about how you work.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.