Valve stem seal replacement - Tips
Thread Starter
Pro
Joined: Nov 2001
Posts: 684
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From: Winnipeg Manitoba
Valve stem seal replacement - Tips
Hi everyone, on startup I am getting alot of blue smoke and it appears that my valve stem seals need to be replaced. I checked the forum and my shop manual on this procedure and just wanted to ask everyone out there if there are any additional tips you can provide. I will hook up the air compressor to each cylinder to keep the valves from falling in the head. Is there any recommned pressure that I should fill the cylinders with, I am kinda worried about dropping the valve in the cylinder, this is kinda of my biggest worry. 
Le Mans Master
Joined: Nov 2006
Posts: 5,262
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From: I'd like to propose a toast... to internal combustion and wind in the face.
Though I can't remember exactly how much air pressure I used, I think it was around 50-60 psi. I used the lever type spring compresser and sometimes when I would compress the spring I could hear a rush of air around the valve because the retainer wasn't broken loose from the keepers. If this happens just tap around on the retainer until it breaks loose from the keepers.
The only tips I can offer are:
1. Place is piece of clear plastic fuel line over the valve spring stud to prevent metal shards from going everywhere. You may have to drill out the hole in the spring compresser somewhat in order for it to fit over the plastic fuel line. I used plastic fuel line becuase it's thinner than vacuum hose.
2. Always use a small antenna type magnet to remove the keepers.
3. When re-installing the keepers I used a tiny bit of vaseline to hold them in place while I was de-compressing the spring.
Good luck
The only tips I can offer are:
1. Place is piece of clear plastic fuel line over the valve spring stud to prevent metal shards from going everywhere. You may have to drill out the hole in the spring compresser somewhat in order for it to fit over the plastic fuel line. I used plastic fuel line becuase it's thinner than vacuum hose.
2. Always use a small antenna type magnet to remove the keepers.
3. When re-installing the keepers I used a tiny bit of vaseline to hold them in place while I was de-compressing the spring.
Good luck
Thread Starter
Pro
Joined: Nov 2001
Posts: 684
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From: Winnipeg Manitoba
Thanks for the advice and tips, I found a good tech session here at the forum on this and its pretty straight forward, but I always like to ask if there is anything else I should watch out for, sometimes the easy stuff can turn into a problem.
Pro
Joined: May 2003
Posts: 593
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From: London England
When you connect the air compressor, make sure it doesn't rotate the engine.
If the piston is at the top then even if you drop a valve you stand a slight chance of getting it back in place without taking the head off. If the piston moves to the bottom cylinder you'll stand no chance.
Another trick is to take some rope, small enough to go through the plug hole and feed it into the cylinder, using it to fill the space between the valve and piston.
Also if the stem seals come with a little plastic see-through 'hat' to go over the end of the valve while you fit the seals then use it. Sometimes the keeper grooves can be quite sharp and cut the edge of the new seal.
If the piston is at the top then even if you drop a valve you stand a slight chance of getting it back in place without taking the head off. If the piston moves to the bottom cylinder you'll stand no chance.
Another trick is to take some rope, small enough to go through the plug hole and feed it into the cylinder, using it to fill the space between the valve and piston.
Also if the stem seals come with a little plastic see-through 'hat' to go over the end of the valve while you fit the seals then use it. Sometimes the keeper grooves can be quite sharp and cut the edge of the new seal.
Thread Starter
Pro
Joined: Nov 2001
Posts: 684
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From: Winnipeg Manitoba
A coworker of mine as does the shop manual suggest that the piston be at TDC when removing the spring. As with your comment he also suggested that if for some reason the valve does drop and the piston is at TDC, I should be able to get the valve back up again. I was kinda worried about the valve dropping and not being able to retrieve it if something did go wrong. Thanks to everyone for the tips.
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
I can only confirm that the engine will rotate with air pressure on the piston at TDC. So hold it somehow.
And yes, make sure that the piston you loosen the valves on is always at TDC.
Some of the keepers are so tight that they need a good knock, strong enough to drop the valve.
I did this on my BB years ago , installed Umbrella seals because the old once where all cracked.
Helped a bit , but the heads really require rework because the oil consumption is still kind of high. No blue smoke anymore.
Here a old Umbrella seal, you can well see the crack
Here the tool I used to push the valve springs down.
Good luck. Günther
I can only confirm that the engine will rotate with air pressure on the piston at TDC. So hold it somehow.
And yes, make sure that the piston you loosen the valves on is always at TDC.
Some of the keepers are so tight that they need a good knock, strong enough to drop the valve.
I did this on my BB years ago , installed Umbrella seals because the old once where all cracked.
Helped a bit , but the heads really require rework because the oil consumption is still kind of high. No blue smoke anymore.
Here a old Umbrella seal, you can well see the crack
Here the tool I used to push the valve springs down.
Good luck. Günther
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Advanced
Joined: Dec 2006
Posts: 50
Likes: 1
From: So. Cal. CA
I followed the method/directions from SteveG75 about 5 replies down in this thread:
http://forums.corvetteforum.com/c3-t...l-replace.html
Worked great for me!
Mike
http://forums.corvetteforum.com/c3-t...l-replace.html
Worked great for me!
Mike
Instructor
Joined: Aug 2006
Posts: 188
Likes: 1
From: Kamloops BC
I used the rope method. It was a pain stuffing that rope into the plug hole but there is no chance that you will drop a valve. Also the rope will act as a backing when you try to break free those stubborn keepers.
Dale
Dale
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
faster pussycat: save yourself time & hassle
This simpler & easier. I used a different method and I never looked at a timing mark & never went thru typical valve timing events. I used a lever-type stud-mount Moroso tool. Compressor set about 100psi. Replaced o-rings & added umbrellas. car did & does run aok. I did it last fall & posted here.
here's my post detailing how:
http://forums.corvetteforum.com/1571968952-post23.html
* NOTE * my method above is for HYDRAULIC ONLY ... NOT SOLIDS.
here's my post detailing how:
http://forums.corvetteforum.com/1571968952-post23.html
* NOTE * my method above is for HYDRAULIC ONLY ... NOT SOLIDS.
Last edited by jackson; Apr 13, 2010 at 11:44 AM.
