The Stovebolt Site Forums The Shop Area Engine Shop L6 valve seals - got any installation tips?

Hello Stovebolters!

I need some advice from people who have done this before please.

I'm a novice with engines. I'm wanting to do this right and the FSM doesn't tell me which is best.

I am managing (actually struggling a bit really) to get the valve springs, shields and caps off the valves. Once they are off, the old seals are hard and break in two as I remove them. No big deal.

The new seals are tiny little things. I can't even figure out what they really do. I slide them onto the stem and then struggle again to re-install the shield, cap and lock clips. I'm using the right tools.

Once the valve spring assembly is back together, I worry that the seal has been pushed down the stem and out of the groove where it should live.
EDIT: I read the FSM again. It does say to install the seal just before the lock clips. Accomplishing that seems very awkward and nearly impossible with the valve spring compressor in the way. Arrrgh!

As I re-consulted the FSM, the picture seems to imply that the seal is loaded onto the stem AFTER the shield and cap have been slid over the stem. In other words, the seal goes on last, just before the lock clips are installed.

Once the valve spring assembly is back together, I see no real way to check if the seal is where it should be.

Valve spring removal tool

seals

where the seal lives

FSM picture

For those of you who might be interested, The old "stuff some rope into the spark plug hole trick" to keep the valve from falling into cylinder, really does work. I hand turned the crank until it wouldn't move anymore. Unfortunately, the rope does allow the valve to move up and down a bit. I still could not get the cap locks off using that technique, so I had to resort to the "fill the cylinder with compressed air trick". I still struggle. I tap and wiggle. Lubricate and tap some more. Usually things work loose within 5 minutes and no cussing. I'm careful not to bang too hard, but I do tap on the cap and shield while pressure is in the cylinder. I hope that's OK.

Jay

Filling the cylinder with air is the only way to go, unless here is a valve that won't seal. Tapping on the retainer will loosen it from the keepers. The o-ring seals get hard and brittle with age and almost always break apart. Find all the pieces. It can be tricky to install the seals while compressing the spring and retainer and then the keepers. What about installing umbrella type seals, which install on the valve stem before the retainer. You will not have to worry about the o-ring popping out of place. Some worry about the valve stem not getting enough lube on the older sixes, but I haven't seen it to be a problem. Good luck on your repair.

A Mighty Vac works well. Even a piece of hose over the stem against the retainer and a good vacuum source(the mouth)will work.

Jay, the little seal goes on after the spring and retainer right before the two keepers. They don't really do much, suppose to keep some of the oil from running down the stems. Splash oil will still get the the stems for proper oiling, the seal is to keep pooling oil in the retainers from running down the stem. As long as they are on the stem, they should do what little they normally do. You shouldn't have any problems, I doubt they are much deeper then normal.

Joe

Thanks Joe, Now I'll worry less. I've only done 3 so I'll go back and check those again. I'll do the rest by putting the seal on just before the retainer clips.

Wow, so much work for such little benefit!

Jay

So you all deserve an update. The FSM does say to install the seal just before the retainer clips. So, I re-did the first 3 valves plus 5 more tonight. I did it just the way it said and everything went much smoother.

First, remove the spring assembly.
Remove the old seal and clean the valve stem.
Replace the valve assembly using the spring compressor tool.

Using nimble tiny elf fingers, slide the new seal over the stem and down to the lower of the 2 grooves - see pic. .

Replace the retainer clips - see pic .

Then gently pull the compressor tool upward so the clips are inside the cap while you simultaneously turn the spring compressor to return the spring to its normal length and position - see pic .

Thanks for the technical support! You guys are the best!

Jay