I have a question for all of you related to valve seal replacement. In particular, this is being done on a friend's '94 Buick Park Avenue with the supercharged 3800. I told him to use an adapter for his air compressor to keep the valves from dropping down. Thing is, so far people he's called about getting one don't know what he's talking about (he probably isn't calling the best places). Is there a special name for it? Also, how much pressure is needed?
Thanks, Aron
If he can't find one easily go to Sears and buy their compression tester, it has quick disconnect fittings that will connect directly to most connectors. Or he can use the rope trick. Use 1/4 inch rope and feed it into the plug hole and then bring the piston up to hold the valves in place. Just be sure both are closed when you bring it up to prevent bending valves. As for air pressure, you need about 100 PSI and make sure the piston is at TDC and LOCKED in place before you apply pressure or it will push the piston down and cause problems.
Steve W.
It's just an adapter sleeve. You still have to buy the male end that fits into an air chuck on an air hose to be able to use it A tool company in Lancaster PA (K-D Tools) makes those adapters and they also make a tool for removing the springs.
If you want to do the job without an air compressor, use the "rope trick" that's taught in the military. Get some 1/4" nylon rope (about 7 feet will do) and use a match to fuse the ends. Tie a large nut to one end (so you can't feed too much rope into the sparkplug hole.
Now, on a COLD engine, unhook the battery or remove the fuse for the starter. Then remove all the plugs, back off the adjustment on all the valves and rotate the crank until one of the pistons is at the bottom of its travel (doesn't matter which one, you gotta start somewhere). SLOWLY feed the rope in through the sparkplug hole until most of it is in the cylinder. GENTY rotate the engine to bring the piston tight against the rope (this will hold the valves in place).
You can now remove the spring without worrying about a dropped valve. Just back the piston down when you're through and remove the rope. I've been using this method since the 1960's and have never had a problem with it. Yes, I have an air compressor and the adapters but I prefer this method.
****************************************** I would rather be exposed to the inconveninces attending too much liberty than to those attending too small a degree of it. ~ Thomas Jefferson ~Air pressure works, the "rope trick" works well, but really you just need to put the piston on top dead center on the compression stroke and work from there. The valve will fall to the top of the piston and that's all. Put the new seal on the valve and it will grip the valve tight enough to hold it up while you are installing the spring, etc. I've done lot's of new valve seals like this, saves time and less work, don't even have to take out the spark plugs.
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