I plan on replacing the valve guide seals on my 71 455. I know this can be done without removing the heads by using air pressure in the cylinders to keep the valve shut. I haven't done this before, but have enough mechanical skills where I know I can do it with the proper instructions. Can anybody point me to a document that outlines the entire procedure? Are there any special tools I'll need to get this done? Like spring compressors? Should I replace the valve keepers or any other part while I'm at it? I do have a pair of good rocker assemblies that I plan on putting on at the same time, and maybe push rods too. #2 cylinder spark plug is a bit oily and also has a ticking sound, so I'm hoping this helps those issues. All advise is appreciated. Keith
Keith, The valve stem seals are pretty easy to replace with the heads still on. You will have to have the adapter that screws into the spark plug hole and hooks up to a air compressor. The basic procedure is to get the cylinder that you are working on to top dead center with both intake and exhaust valves closed. Screw the adapter into the cylinder until hand tight and hook up to the air supply with the pressure probably somewhere bet. 60-90 psi. At that point you take your spring compressor and grab the valve spring coil on each side as low as possible and compress it to the point where the keepers will come out. You may have to hit the top of the valve or retainer to get the keepers loose - use a rubber mallet if possible. It helps to have a magnet to get keepers out. Pull the keepers out and take the valve spring out. Then pull off the valve stem seal. You may need to pry them off! To put the new valve stem seals in you go pretty much in the reverse order. My valve stem seals (Felpro I believe) came with a plastic sleeve. This sleeve is used to make it easier to slide the valve stem seal over the valve stem and not damage the seal. Push the seal down in place and put the compressed spring back in place with the retainer in place. Put the keppers back in and slowly release the spring - make sure the keepers stay in position! Do this for the other valve - same procedure. Unhook the air source and adapter and move on to the next cylinder put to TDC (top dead center).
Thanks Carl, this was exactly what I was looking for. This is a great board with a great bunch of people. Keith
Put a dab of white lithium grease on the locks before re-installing. That will help keep them on the valve, so they don't flop around while you're unscrewing the compressed spring.
If you don't have access to a air line with adaptor use a compression gauge hose with a air chuck on the one end.I've made one using a spark plug and knocking out the center so you have just a metal tube with threads,then thread a air chuck nipple into the tube and push a rubber hose over with a clamp,same thing at the end of the rubber hose and you've got your air line to hold the valves up.OR,with the piston half way up on the compression stroke,insert a length of nylon rope thru the spark plug hole,leaving some out,then bring the piston up untill resistence is felt,the rope is taking up the clearance and is up against the valves.When done,lower piston and remove the rope with the end thats sticking out. gary
I knew about the rope trick, but the plug thing is good too. I have a compression tester with multiple adapters that will accept a 1/4 nipple. I'll just screw one in the adapter and just snap on the air line and I should be good to go. Is it really critical that the cylinder be at TDC when pressurizing? The rocker arms will be off so all valves will be closed. And now would be a good time to swap out that Air alternator bracket to a non-air version. PM'd you on that one Gary. Too many irons in the fire at once. Thanks, Keith
Having the piston at TDC is good insurance against a pressure failure. If a valve drops at least it won't go too far and you'll probably find it is still in the guide. Get yourself a little strick magnet so you can grab the keepers if you drop one. Also, a good idea is to have a couple spare keepers since sometimes they "disappear."
Good point on the pressure failure. I was going to get a set of keepers when I was at TA Performance today after work, but just got the seals and a valve compression tool. Guess I'll need to be extra careful not let them "disappear". Man, you guys should see all goodies they have stacked on the shelves. Manifolds by the pallet load in the loading dock, new valve covers of all shapes and sizes stacked 3-4 deep, all those Buick parts was a sight to behold. I just stood there in awe for a bit. A guy could spend a few pennies there for sure. Keith
