advice replacing valve stem seals
Thread Starter
Race Director
Joined: Aug 2000
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advice replacing valve stem seals
All the plugs are out, valve covers are off, rockers are off.
Now I'm compressing the spring and I can move the compressor w/the spring up and down a bit on the valve but how do I get that SOB off? I'm supposed to remove valve spring cap key but don't know how. Also, I'm should be carefull with the keepers but can't even see them.
HELP :lol:
Joel
Now I'm compressing the spring and I can move the compressor w/the spring up and down a bit on the valve but how do I get that SOB off? I'm supposed to remove valve spring cap key but don't know how. Also, I'm should be carefull with the keepers but can't even see them.
HELP :lol:
Joel
Thread Starter
Race Director
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Re: advice replacing valve stem seals (C5 Hardtop)
well, the valve is moving up and down a bit before it bottoms out on the rope in the cylinder.
Still cant finger out how to remove the spring. Any ideas?
Joel
Still cant finger out how to remove the spring. Any ideas?
Joel
Melting Slicks
Joined: Jun 2000
Posts: 3,215
Likes: 6
From: Tampa Florida
Re: advice replacing valve stem seals (C5 Hardtop)
I used same technique, except brought the piston carefully to seat the rope. This eliminated the valve movement you are experiencing.
You may also need to tap the locks/caps with a hammer to unseat things if they have lots of miles on it.
My engine was out of the car and was still somewhat of a pain...so normal.
Good Luck:)
You may also need to tap the locks/caps with a hammer to unseat things if they have lots of miles on it.
My engine was out of the car and was still somewhat of a pain...so normal.
Good Luck:)
Thread Starter
Race Director
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Re: advice replacing valve stem seals (No Go)
Part of my problem was the spring wasn't compressed enough. What I though was some C clip was the keeper (?).
Now with the keepers off, I can't get the spring over the valve steem without forcing it. There appears to be a o ring that is keeping me from lifting the valve spring off.
Do I just force it up and over? I took a pick of what I'm talking about
http://www.zracer.com/images/valvesping.jpg
Joel
Now with the keepers off, I can't get the spring over the valve steem without forcing it. There appears to be a o ring that is keeping me from lifting the valve spring off.
Do I just force it up and over? I took a pick of what I'm talking about
http://www.zracer.com/images/valvesping.jpg
Joel
Melting Slicks
Joined: Jun 2000
Posts: 3,215
Likes: 6
From: Tampa Florida
Re: advice replacing valve stem seals (C5 Hardtop)
I don't have experience with those type of seals, but from what I gather in magazines is that is also part of the seals.
It is an o-ring that goes on after the retainer is installed...so I would remove the oring before pulling the retainer. Hopefully you have new ones to replace them with.
It is an o-ring that goes on after the retainer is installed...so I would remove the oring before pulling the retainer. Hopefully you have new ones to replace them with.
Thread Starter
Race Director
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Re: advice replacing valve stem seals (No Go)
I'm installing Unbrella type seals instead of O rings.
Once I get that O ring off, I should pull the spring w/compressor as you see it off of the valve stem then uncomress it on the bench?
After doing one valve, I will hopefully be able to start sailing along ;)
Jeol
Once I get that O ring off, I should pull the spring w/compressor as you see it off of the valve stem then uncomress it on the bench?
After doing one valve, I will hopefully be able to start sailing along ;)
Jeol
Thread Starter
Race Director
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Re: advice replacing valve stem seals (C5 Hardtop)
Got the spring and keepers off ;)
The unbrella seal fits over the stem OK but its very loose around the head. I expected it to fully seat on the cone looking thing where the valve goes into. :confused:
Is that expected?
Joel
[Modified by C5 Hardtop, 4:02 PM 5/25/2002]
The unbrella seal fits over the stem OK but its very loose around the head. I expected it to fully seat on the cone looking thing where the valve goes into. :confused:
Is that expected?
Joel
[Modified by C5 Hardtop, 4:02 PM 5/25/2002]
Melting Slicks
Joined: Jun 2000
Posts: 3,215
Likes: 6
From: Tampa Florida
Re: advice replacing valve stem seals (C5 Hardtop)
Sorry, I was pulled away from computer...but I don't think I can help anymore as I've always switched to PC seals that are different than the umbrella....:(
Anyone else?
:)
Anyone else?
:)
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Race Director
Joined: Sep 2000
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From: The Top of Utah
Re: advice replacing valve stem seals (C5 Hardtop)
If it is just a plain rubber/neoprene umbrella with no metal, it is supposed to be "loose" on the OD of the valve guide. It is called an umbrella seal for a reason. DO reinstall new "O" rings, also. Good luck.
Le Mans Master
Joined: May 2002
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From: 10.70 @ 124mph, Stock Bottom End @ 3620lbs, ECS Racing Team Member. The 1st NMCA LSX Index Rumble World Champion. 2011,12,13 Champion
Re: advice replacing valve stem seals (C5 Hardtop)
The valve seals should fit tight. I just replaced mine last week. I filled the cyclinder with air, Then used a spring compressor. I did not replace the O ring seals. They are not needed. I had to tap the retainers with a hammer to free them. Then I compressed the spring, Remove the keepers, Release the tension of the spring, Tap the spring from the head, Broke off the O ring seal - The O ring seal was hard and came off in pieces and reverse process to install. I had a problem with the spring compressor making contact with the intake runners. Car runs great now. 
Le Mans Master
Joined: May 2002
Posts: 5,446
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From: 10.70 @ 124mph, Stock Bottom End @ 3620lbs, ECS Racing Team Member. The 1st NMCA LSX Index Rumble World Champion. 2011,12,13 Champion
Re: advice replacing valve stem seals (89NYFINESTVETTE)
If the umbrella fits loose, It will not adjust to fit. You should have to apply pressure to slide the umbrellas over the head. You are defeating the purpose by installing an unbrella that is loose. The oil will get by the seals.
Safety Car
Joined: Dec 2000
Posts: 3,767
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From: Jacksonville Fl
Re: advice replacing valve stem seals (89NYFINESTVETTE)
Agreed. Don't waste your time if the seals do not go on tight.
I like using the rubber seals that have the spring metal band around the bottom to hold onto the valve guide. Get rid of the plastic o-rings. I also recommend you replace the valve springs with a set of better than stock replacements ( Pioneer 'Z' springs are the common generic better than stock pressure replacements that work very well and cost very little ). You can get springs for around $35-$40 a set that will breathe new life and smoothness into a high mileage L98.
I can't stress it enough...if the motor has enough miles to wear out stock valve guide seals...the springs are shot as well, and you will likely not be able to get the valves adjusted very well when your done unless you put new ones in.
I like using the rubber seals that have the spring metal band around the bottom to hold onto the valve guide. Get rid of the plastic o-rings. I also recommend you replace the valve springs with a set of better than stock replacements ( Pioneer 'Z' springs are the common generic better than stock pressure replacements that work very well and cost very little ). You can get springs for around $35-$40 a set that will breathe new life and smoothness into a high mileage L98.
I can't stress it enough...if the motor has enough miles to wear out stock valve guide seals...the springs are shot as well, and you will likely not be able to get the valves adjusted very well when your done unless you put new ones in.
Thread Starter
Race Director
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Re: advice replacing valve stem seals (BBA)
Thanks for the tips.
The unbrella fit loose around the boss. Apperintly that is by design and only special ground heads will fit the unbrella snug. The seal fit real nice and tight over the valve stem. It was just the bottom I was worried about but its not a big deal. I saw a few posts indicating I should use both unbrella seals and O rings. I just did unbrellas and that was it. No more oil smoke, runs STRONG.
Althougt the bolts that hold the rockers werent all that tight :cry (can you say re-do)
Its all done and she runs great! I didn't know what I was doing which made a 1/2 day job into a full day but had lots of help from guys at chevytalk.com forum. Save my **** $300 bucks! BTW, this was on a 74 1/2 ton ;)
Joel
[Modified by C5 Hardtop, 8:18 PM 5/26/2002]
The unbrella fit loose around the boss. Apperintly that is by design and only special ground heads will fit the unbrella snug. The seal fit real nice and tight over the valve stem. It was just the bottom I was worried about but its not a big deal. I saw a few posts indicating I should use both unbrella seals and O rings. I just did unbrellas and that was it. No more oil smoke, runs STRONG.
Althougt the bolts that hold the rockers werent all that tight :cry (can you say re-do)
Its all done and she runs great! I didn't know what I was doing which made a 1/2 day job into a full day but had lots of help from guys at chevytalk.com forum. Save my **** $300 bucks! BTW, this was on a 74 1/2 ton ;)
Joel
[Modified by C5 Hardtop, 8:18 PM 5/26/2002]
Instructor
Joined: Sep 2000
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Re: advice replacing valve stem seals (C5 Hardtop)
The Viton seals are the more positive seals as referenced above- cost about double, gets rid of the umbrella seals.... the rubber o-rings are what get hard and leak, not the umbrella seals. Don't worry about ropes or air compressors; if you bring the piston up to TDC, there isn't any room for the valve to drop down- it's move about an 1/8th of an inch, still plenty of room to work on the seals.
Thread Starter
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Re: advice replacing valve stem seals (jcazin)
Even with the piston at TDC, I still needed the rope. The keepers were stuck on the shaft and needed a nice beating with a socket and the rope helped soften the impact on the valve.
Also, too much play and I couln't get the keepers out as the valve would fall down too far.
joel
Also, too much play and I couln't get the keepers out as the valve would fall down too far.
joel
