Changing Valve Stem Seals

jdemara

New Member
Apr 28, 2008
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North Delta
Is it at all possible for me, or a machine shop to replace my valve stem seals with the head on? I have heard of using compressed air to keep the valve up while changing the seal, is this do-able?

I know there are TONS of threads on blue smoke on startup.. and thats what I have.

Appreciate any knowledgable feedback:)
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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Fullerton,CA
Yes. You need to put compressed air(like 100psi)in the cylinder your working on. You then pull the cams, buckets, and then spring keepers out. Remove the springs replace the seals and install everything. Have to work on 1 cylinder at a time.

If you take it to a shop there most likely going to charge you for taking off the head tho and then they will do it that way.
 

jdemara

New Member
Apr 28, 2008
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North Delta
I am thinking of taking all necessary parts off myself at home, and get a free tow to the machine shop to get it all done. Good to know it CAN be done with the head on. Has anyone had a machine shop do this, or know a vague price range I should be looking at?...
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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Fullerton,CA
Might want to verify that if you do that they will even do it like that.

Not a clue what they will charge but general labor can get from like 50-100$ an hour so...
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
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Arizona
www.supramania.com
I did mine with the head on. I used rope in the cylinders to hold the valves up. Do one cylinder at a time. Not easy, but less overall work than removing a good sealing head.

Of course my head took a dump on me a few months later so all that preventative work on the Damn valve seals was radically for nothing...

Sent from my ADR6400L using Tapatalk
 

adampecush

Regular Supramaniac
May 11, 2006
2,118
3
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Edmonton
Filling the cylinder with rope worked quite well for me. be sure the rope is fairly stiff so it doesn't try to knot itself inside the cylinder. Other helpful tools include a valve keeper removal/install tool ($45 and makes removing and installing the keepers an absolute breeze) and a set of pliers for the valve stem seals.
 

suprarich

Guest
Nov 9, 2005
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ohio
Machine shops don't change seals on running motors, garages do. I never liked the rope trick. You are putting contamination directly into the cylinder bore and always run the risk of leaving something behind. I prefer air, but then again, I prefer to remove the head and do a complete valve job.
 

jdemara

New Member
Apr 28, 2008
285
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North Delta
removing the head is not in my to-do list right now. Head gasket was done properly by previous owner with ARP hardware... but "forgot" to do the valve seals. I am doing a 2JZ swap in less than 6 months, so I just wanted these valve seals changed out to tie me through.
 

Grandavi

Active Member
Sep 25, 2008
2,663
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Calgary, Alberta, Canada
Im in same boat.. want to do the valve seals with the engine in the car.. and not touch the head. To get the cylinder filled with compressed air.. what is the trick for that? Is there a plug you can buy?
 

Devin LeBlanc

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Apr 7, 2010
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Las Vegas NV.
I have done it on several cars with the heads on. If you have the right tools its easy. I just did an evo, Took me about an hour to do it. Used compressed air, I personally don't like the rope trick but have done it both ways.
 

adampecush

Regular Supramaniac
May 11, 2006
2,118
3
38
Edmonton
Grandavi;1744910 said:
Im in same boat.. want to do the valve seals with the engine in the car.. and not touch the head. To get the cylinder filled with compressed air.. what is the trick for that? Is there a plug you can buy?

You need a 14mm ISO thread to compressor fitting adapter, and a compressor that can supply enough CFM (hint, not the crappy tire twin stack special). If you lose pressure, you're in a world of trouble.
 

dmiller

suspension>power
Jun 30, 2009
210
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Vancouver, Washington
Devin LeBlanc;1744942 said:
I have done it on several cars with the heads on. If you have the right tools its easy. I just did an evo, Took me about an hour to do it. Used compressed air, I personally don't like the rope trick but have done it both ways.

What are the "right tools" you are talking about? Just a valve spring compressor, and this adapter for the compressed air trick? I'm probably going to end up doing this really soon and don't want to take the head off since it has a new hg with arps. Thanks.
 

wardog

R.G.V WARDOG
Jan 19, 2006
564
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ALTON, TX
If you have a Harbor Freight near you go and buy a Compression Check Kit. It comes with the air adapter and the kit is always a good thing to have around. I have done this job both ways too. If you don't have an air compressor then the rope will get the job done. Just don't buy a rope that shreds quick get a GOOD CLEAN ONE... :beer: