Valve Seal Replacement ?

[mgj57]

I've searched the posts and found some good stuff on valve seals. Looks like I have the classic symptom - big puff of smoke at start up. It's on one side and probably just one cylinder since plug #1 seems to be the one that's fouled.

I'd like to try replacing the seals without removing the heads like I see mentioned in some of the posts but I didn't find any instructions on how to keep the valve from falling into the cylinder...

Any ideas would be appreciated!...

[76GMC1500]

I would remove the pushrods so both valves are shut, install an adapter in the sparkplug hole that allows you to hook it up to air, and put 90 psi or so in the cylinder. The engine will probably rotate as you pressurize the cylinder, this is why you cannot just put it at TDC so both valves are closed, you have to remove the pushrods first. Don't forget to put rags in the oil holes in the head in case you drop a keeper.

[R Pope]

A standard air hose fitting will fit a 14mm plug hole, not perfect but good enough for the job at hand. Just don't overtighten it, and it will work.

[mgj57]

Thanks guys for the ideas... I'll try 'em out and let you all know how it goes.

[Sinister]

If the air hold gives you any trouble, you can also bring the piston to top dead center and shove some nylon rope in through the spark plug hole. It will coil up on top of the piston and give the valves no room to drop down. Just a thought.

[mgj57]

Well, thanks for all the advice. It took some doing but I got it done. For a new guy my advice would be to invest in the right tools up front. The $10 angled bar spring compressor isn't worth it since one hand is stuck holding it down. The $32 twist type is a mess too since it compresses each side a bit differently and tends to slip off. The $54 one that threads on to the rocker stud and locks the spring down with a lever action worked great. That in combination with air worked best for me and once I figured that out, I got them changed out in about an hour. I used 2 air hose fittings for the spark plug holes from Napa (about $10 each)... put about 100 psi one cyl. forcing it to the bottom, found the two that were then at TDC and put about 80 psi on those (one at a time of course) and changed the seals on the TDC cyls. Piece of cake! And best of all, no smoke at start up anymore!!

Thanks again guys!

[stylingZ]

Congratulations on a job well done not to mention solving your problem. Believe me HRC members are the BEST when it comes to sharing their knowledge and advice when you need help.