Re: Valve seal replacement

[e6941tb@gnn.com]

Steinbrueck, GL wrote:
> 
> Do any of you have words of wisdom on replacing valve seals.  I have a set
> of Viton ones.  I plan to pull each valve spring in turn, letting the piston
> hold the valve from falling out while I replace the seal.  I don't want to
> pull the head.  Is there anything I should watch out for?  Do the new seals
> and bands just push on?  TIA

Hmmm, sounds scary. I always use compressed air to hold the valve up
(closed), when replacing the seals. My guess it would be extreamely
difficult to compress the springs and put the conical keepers back on if
the valve is dropped down and rests on the piston's top.
Get an adapter hose (only a coupla bux @ Pep Toys), screw it in the
spark plug hole and keep the cylinder filled with air at about 90-100psi
(you do need a compressor with a tank for this). BTDT by myself and a
lot of other people whom I know.

I would also suggest that you buy the special pliers (Lesli from Pep
Toys for example) to pull the old seals off. It will save you a lot of
skin on the knucles.

The new seals get seated on the stems with a light tap of a hammer over
a special tubular tool. I made mine myself out of a siutable brass
stock. Make sure that the tool will be pressing against the metal part
of the seal ONLY! They are very easy to damage. Due to the same reason
make sure that you have a little plastic "condom" (should be in the seal
kit), that you put on the stem BEFORE you slide the seal over it. Be
very gentle and try not to fringe the tender lip of the seal. Also watch
out for that spring band, it is very easy to slide off the seal's neck.

Ah, one more thing: lubricate the seal and the plastic piece prior to
installation. Regular motor oil will do.

Igor Kessel