Valve Seals and Valve Guides

[triffecpa]

What's the trick for removing the metal sheathed valve seals on a '80 GS1000 head? I tried squeezing them off center with a pair of pliers to break the rubber seal's grip on the guide. Managed to get five of them off so far, but the bad news is that I also managed to break two of the valve guides off flush with the bottom of the follower cavity. Not sure if that was my "ham-fistedness" or if there was a problem with them. On the last three I was going to try cutting the metal sheath on the seal with a dremel tool and see if the rest of the seal doesn't come off more easily. The follow up question of course is "how hard is it to replace the broken valve guides?" Do I need to buy oversized guides or can I buy stock replacement ones? Thanks guys. Tracy

[nastyjones]

As far as the seals go, you usually can't remove them without destroying them. The good news is they are cheap as long as you don't go to the dealer.
You should be able to use stock replacement guides for about $7-10 each but the bad news is they have to be pressed out & new ones pressed in on a press, a 5 ton will do if I remember right. Have a proper machine shop do the job. You are dealing with an aluminum head & bronze guides. The labour shouldn't be that much.

Paul

[Footy.]

What's the trick for removing the metal sheathed valve seals on a '80 GS1000 head? I tried squeezing them off center with a pair of pliers to break the rubber seal's grip on the guide. Managed to get five of them off so far, but the bad news is that I also managed to break two of the valve guides off flush with the bottom of the follower cavity. Not sure if that was my "ham-fistedness" or if there was a problem with them. On the last three I was going to try cutting the metal sheath on the seal with a dremel tool and see if the rest of the seal doesn't come off more easily. The follow up question of course is "how hard is it to replace the broken valve guides?" Do I need to buy oversized guides or can I buy stock replacement ones? Thanks guys. Tracy

The trick with valve stem seal removal, is to get them turning on the guide before you try to pull them off.

First spray the old seals with a good penetrating lubricant. Then use a good pair of pliers to grip them, and get them turning. This spreads the lubricant and breaks the seal to guide bond.

Snap on tools makes a special plier for stem seal removal, but the key is still to break the bond by first twisting the seals.

Footy.

[triffecpa]

Thanks guys. - I'll try the spray lubricant on the last three seals. Yeah, it'd be too damned easy if I could replace the guides myself. When does this racing thing start to get cheaper anyway? :-)

[duaneage]

Find a deep well socket that fits over them, press down and twist them off.

[silverhorse47]

Replacing valve guides is not a totally impossible at home procedure if you have the right reamers and the ability to use them on center. The 'hole' left after driving or pressing out the broken guide must be reamed on center to spec, then the new guide has to be hopefully shrunk to size with cold while the head is heated, or else pressed in with a support inside the guide. Then the guide has to be reamed to fit the valve stem. Usually one would then have the valve ground to fit the new center. Hope this helps. Generally it is unnecessary lateral force that breaks valve guides, although overheating the head can cause them to drop into the cylinder.

This is not good, obviously.

Good luck.
S.

[BadBillyB]

I would highly recommend having a motorcycle race shop like APE replace the broken guides and any others that are not up to snuff. This will require the valve seats being redone also. This is not a job for the home mechanic as I have done this myself years ago and was not pleased with the results. You can save money by assembling the head and shimming the valves yourself.....Billy