Valve guide seals

I got a pair of valve stem seal pulling pliers, easy breezy with them.

You can pop an old valve in the guide and use a pair of pliers to squeeze the seal onto that and push the lot off the top of the guide using the valve, if that fails carefully split the seal down the side with a small sharp chisel. or burn the bugger out with a blowtorch...

I use a piloted drift to refit them, makes sure they go on nice and square, if you don't have a drift use a valve to guide the seal onto the guide.



  Keith.


    Keith
 
I assume we are talking about your triple, not the 750 SFC, right?

The easiest way ist to take the engine out and strip the head...

Depending on if you want to replace all 3 or just the outer ones, you can even leave the engine in the frame to do it, it's just a lot of fiddling (on my bike it was just the right one that gave up and we did not want to pull the engine completely so we made a temporary fix with just replacing the right one. Lasted for a looong time without oil consumption...):

-tank off, cam cover off, spark-plug from cylinder one out, Cam-chain open, intake came out etc. - remove everything so you come to the valve with the spring mounted
-if you do not have a pressured-air-supply-to-spark-plug-hole adapter, turn the engine so the piston of the according cylinder you are working on is on TDC. -Take a welding wire and bent the lower end 1 cm roughly. Make sure you have an assisting mate around that puts this wire through the spark-plug-hole now and holds the valve up as much as he can during the next steps of the surgery...
-take a Valve Spring remover-tool (one like one of the following:

http://www.ebay.de/itm/Ventilfederspanner-Federspanner-fur-Ventilfeder-AUDI-VW-NEU-TOP-/321700786606?pt=LH_DefaultDomain_77&hash=item4ae6dc71ae

http://www.ebay.de/itm/Ventilfederspanner-SV-OHC-OHV-Ventilfeder-Federspanner-fur-Opel-VW-Audi-Mercedes-/251156874926?pt=LH_DefaultDomain_77&hash=item3a7a1dc6ae)

  and remove the valve Spring

-now - with a bit of fiddling - you can pull the seal with a long nosed pliers.

for re-installation, a tube with an inner diameter of 8mm (larger than the valve shaft) and optimally an outer Diameter at least the size of the valve guide seal helps. put the seal over the shaft of the valve and tab it down with the tube and a small or at least light hammer. Re-install the valve spring while your mate pulls it up as much as he can with his welding wire, re-install all other parts, check timing, re-mount the valve cover etc. and you're done.

 
The head is sitting on my bench Lothar. It's a head I brought some time back to replace the original putty like one! Wasn't planning on swapping heads just yet but when I checked the valve clearances the other day the ex. cam was binding, again!! After fucking with shims again to free up the cam the M8 time cert I installed some time back felt like it was pulling :o
This is one seriously fucked up head!!
The head I brought came with the original valves so I had the inlets valves reground and I just lapped them all in. Have a new set of seals to fit hence seal removal question.

                                                    "burn the bugger out with a blowtorch..."

Sounds very drastic Keith!! Last resort! I kind of like your other suggestions over that one. I have old valves so will do what you suggested. Thanks.
 
Hi rob - Here's some like keith was talking about - got a "Sealey" pair myself - regards - Phil

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1311.R1.TR2.TRC1.A0.H0.Xvalve+seal+pliers.TRS0&_nkw=valve+stem+seal+pliers&_sacat=0
 
Rob,

They are a bit of a bugger sometimes.  The seal pliers Keith mentioned are great.

Either a small chisel or sharpened screwdriver blade (no, not your favourite Snap-On screwdriver, some old shitty one from the bottom of the rusty old toolbox does nicely) driven squarely through the metal part will seperate the seal easily.  Don't be tempted to squeeze the blade or chisel between the metal ring and guide, this can break the guide spigot where the seal fits!

piet
 
I made up some seal pliers similar to those shown by Phil, easy enough with a lathe, a welder and an old set of pliers, not so easy without those things.  If the seals are on tight then it is difficult to get them off without such a tool as there's no space as you've found.

It's interesting that the Lav seals are so tight on there.  I just rebuilt the 3lt 6 engine in our BM 530i and although I pulled them off with the pliers I made for doing Lav heads, they were quite easy to get off (even after 245,000km).  The new seals came with a little plastic sleeve to slip over the end of the valve stem, You sat the valve in the guide, put the plastic sleeve over the end then just pushed the seals on by hand with very little effort.  It seems they don't need to be so tight on the guide.

As with Keith, I've had to make a installation guide to make sure the damn things go on straight on a Lav head, although possibly my difficulties were with non-factory guides which might have been oversize and certainly had too little chamfer at the top.
 
After fucking around with various grabbing devices without much success I reverted to your method Piet using a small 3mm chisel, deformed the metal ring enough for the seal to come loose.
1 down 2 to go.
Have welder, old pliers and access to a lathe so could make a set but I hope I'll never have to do this again so won't go to the trouble of making a set just yet.
So what trouble can I expect when I get around to fitting the new seals?? As with everything on this motor nothing is as easy as it should be!!!
Now to pull the old head off the motor and salvage the springs/retainers for the replacement head. Hoping I don't have to send the head off for a valve job, if so it'll be another 6 months before I find the enthusiasm. I just don't trust anyone in WA, and don't have the funds to send to Red to do the job after spending over $2500 on the original head for it to end up a useless lump of ally. The ally is so soft that the shim I fitted under the #3 cam bearing left an inprint in the surface face :o The Motodd is on it's last warning, anymore problems and it'll be on evilbay!!
Thank fuck I have the BM for 2 wheel transport :D
 
Another method for replacing stem seals w/ engine together is to lower piston to BDC & feed in 12" of 3/8" cotton rope & leaving a bit poking out of the plug hole, then raise the piston until the rope pushes on the valves. Allows for solo work w/ no rush. Good luck with the head, Rob-I'm sure it will be running soon.
 
Rob,
I made a guide jig that uses the bucket bore so you can tap the new ones on nice and square.  Happy to send it to you if you like.  How hard they go on depends a lot on the guide I think, not all have the requisite size or chamfer. Either way the jig does help though.  If you don't want the hassle, just set the seal into a suitable size socket (10mm works well IIRC) on the end of a short extension, lube it up and tap it on. The longest extension in your kit helps you estimate the right angle of the dangle to keep it parallel with the bucket bore.
Cheers
SteveB
 
Hi Steve,
I found a length of 25mm nylon rod that I drilled a 11mm hole in the end deep enough to take the valve stem an used the valve as a guide. A smear of oil and they pushed on quite easy.
Just swapped the #1 ex valve, had to fit and remove it twice to re lap till it sealed fuel poured down the port. Now for the inlet valve. :)
 
Ok next question, I've had the valves in and out several times to hand lap them. Each time I refit the springs and pour fuel down the ports to check sealing.
I've got them sealing to a stage where fuel will sort of vapor out after a moment rather than flow out.
Is this acceptable or do I need to remove the valves again and keep lapping?
Cheers
 
Rob,

You wrote you had the seats re-faced.  Did you have the valves re-faced as well?  If you did, lapping should be a 5-minute job at max.  If not, you'll be lapping till the end of time, I'm afraid.

Poppet heads are rarely exactly concentric to the stem after a while.  Hand-lapping will drive you mad before you get them to seal properly.  Only way out is to have the seating surface ground to the appropriate angle.  Ideal would be a perfect seal on all valves, hard to achieve if something is still slightly out of whack.  Guess a very slight weepage might be acceptable for your purposes.

Have you ever done this test on a used head?  Quite normal to have exhaust valves badly leaking due to carbon build-up, inlets usually keep a nice, clean seat. 

piet
 
Hi Piet,
I didn't touch the seats, only the 3 inlet valves were faced. Problem is I live far from anywhere and I don't want to give it to the local engine builder in Albany, probably fine for a massy tractor but not the Motodd head! No one in Perth either, especially after my last experience with the original head. So that leaves Red and that'll end up way out of my zero budget.
As I said, it is what it is. I have a nice even 1mm seat face ground onto the valve face.
I'm trying to get the bike back on the road for minimal cost. In a couple of years once the house is finished I'll be able to afford a proper head job, till then.........................
I'll have another go at lapping and leave it at that.
Cheers
 
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