Valve stem seals, without removing the cylinder head

[Steve]

made a pvc "special tool" and put it in place,

The 25mm PVC I used fitted in the bucket bore, but the spring retainer pushed up inside the PVC. (ie the ID of the tube is too big) and didnt compress the spring at all.

I will buy the next size down PVC today and try again tonight.

Not sure about using the "next size down", try looking for the heavier-duty PVC with thicker walls, or maybe a coupler from the next size down.

Either one will have thicker walls, which should engage the retainer.

.

[john82q]

I did it!

piece of p iss, all too easy... really, it was no harder than any other engine i've worked on. (i'am excited, cant you tell.)

So thinking way ahead of you Steve, at lunch time to day I brought a PVC joiner, its for 20mm pipe and has internal thread one end for tap etc, (nice thick wall)




made a new special tool and put it in place.



now got out the piece of timber, one end it the frame the other i tied down with a rachet strap. used the crashbar as it was handy.



keepers came out with tweezers, relased the wood , took spring and all out.

Now what was difficult, was to get the old seal out, it was so dry and hard that i really had to mangle it up with the long noses before getting it out with a deft heave.




new seal in , pushed down with a long reach socket till it clicked into place, oiled it first.





rerigged the wood and I dipped the collets in grease and stuck them to the valve.




undid the spanner, back the pressure off, pull out the rope, I jiggled the valve with the wood and special tool to make sure things were seated.

put the bucket back in and moved on to next cylinder.

being on the outside got a better shot of installing keepers, if you compress the spring just enough it really isnt hard at all. (for me at least)



stuck on with grease


So there was wasnt really any drama, and really putting the keepers was no harder than any other head, ive done. actually access was'nt too bad at all.

So seals are in, leaving the mundane reassembly of cams and shim adjustments etc for another day.

[bccap]

Well done, John ! Hope this thread gets saved somewhere on the site.

[Guest]

John I didn't post earlier coz I had no idea, but I'm glad to see you got it done!

Can I suggest taking some extra photos of the tools and sticking a thread in the tips and tricks forum?

I'm sure others will find this very handy!

I for one am well aware of how you can come up with the most useful suggestions to things that just seem impossible or difficult, so I'll be honest and say I'm not surprised you pulled it off...

[Suzuki_Don]

John, Well done. I didn't think it was possible. But you've done it against ALL popular opinion (including mine). Excellent pictures too, helps others that might want to attempt this task. That bolt arrangement looks like an interesting tool, it seems to suit the application ideally.

Again, Congratulations, a job well done, for the price of eight seals.

[hampshirehog]

Again, Congratulations, a job well done, for the price of eight seals.

....and a bit of pipe Don!

Good job John.

[Suzuki_Don]

....and a bit of pipe Don!

Good job John.

Don't forget the grease Wally.

[Nessism]

Fantastic work John!

It's nice to watch a real master mechanic at work!

[john82q]

total cost
Seals $27.88 including freight, the viton ones on ebay
PVC union $3.20

every thing else was already in the shop, the grease is years old...

THe flash looking bolt and nut came from the clamp kit for the Milling machine. really any bolt would do. it was good that the pvc and the bolt made up to a solid unit, with some epoxy.

[tatu]

Job done! John rope trick!

[mike_of_bbg]

Awesome. I thought it would be do-able, but more difficult than you make it look. Another great arrow in the quiver...

Thanks muchly!

[tkent02]

I guess we can all learn a new trick every day. THanks for showing us how it's done.

[TheCafeKid]

Very cool. I only have one...gripe? I guess? But if the seals are long enough in the tooth to need replaced, wouldn't you want to check the rings and such too? I realize perhaps the point of this excerise was to save money on buyin gaskets, but it would be really heart breaking to do all of that work, then put it back together and have it still burning oil...as someone who's actually had that happen, I say this from experience...heh.

Nonetheless, a very nice job, and thanks for writing it up!

[tkent02]

A bike with 30 years of drying out hardened seals might have very low miles and nearly brand new rings. If it smokes but has good compression and no leaks it's a great candidate for this.

John, not counting thinking time and messing around with your tools, how long would this whole procedure take the second time?

[Guest]

Are you really sure you want to "attempt" this? Sounds like you need the help of a master, like Houdini. Short of that, it sounds like a desparation
attempt to save from the cost of purchasing a few gaskets. If you do this I wish you well, good luck. If it were me, I'd pull the head off.
Ropes in the cylinder, air to keep the valves up, you've got to be kidding me! I can visualize the anguish already.

You made a believer out of me! That is the most unique maintenace action I've seen. Well thought out and executed. Got any more tricks for us to see?