need to replace one valve seal but my tool will not work. can anyone steer me in the right direction for the correct tool to remove spring, keeping in mind that the head is bolted up.
Removal: I recommend that you place a 5/8" socket on the spring retainer and give it 1 sharp smack. This helps loosen the locks (or keepers) and makes it easier to get the locks out once you have the spring compressed. Use a small strong magnet to lift the locks out once they are loose.
Assembly: coat the valve stem with oil and the oil seal as well. Use some heavy grease on the valve stem lock area to help hold the locks in place when you put them back in.
Cylinder head on the engine:
Rotate the crank to bring the cylinder up to TDC on compression stroke. Use compressed air to hold the valve shut; use about 90 PSI. If you hear lots of air hissing out, either the valve isn't closed or you have other problems. Don’t proceed any further until you have found and fixed the problem. This air trick only works well if you have a way to keep the engine from turning over while you are working on it. For a manual transmission, this is easy; Just put it in 5th gear and put some chocks to block the wheels from moving. You will have to be creative if you have an auto trans or the manual trans and clutch are not working correctly. Remember that without the valve spring, retainers and locks properly installed, you can't take the air pressure off the cylinder you are working on.
I have an old KD tools thread style compressor. It has two fingers that grip the lower end of the spring and a handwheel to turn. Works better than the other several I have tried, and not expensive. Bought a big c clamp style last year and returned it. the KD works heads on the car or heads on the bench.