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compressor for valve oil seal change

275 Views 6 Replies 7 Participants Last post by  77 260Z
has anyone used an air compressor to pressurize the cylinder for a valve stem oil seal change? i have a friend who tells me he did this to keep the valve seated. it was done on an older american car and he doesnt remember how much pressure it took. i have a spark plug adapter with my compression guage which could be adapted for this purpose.
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yes you can do it with these
I've tried that method and the old tried and true method of
pushing nylon rope into the cylinder bore at TDC...and find that
the rope filling method is better.
1 - there is no blow by noise
2 - Take all the time you need...the rope is not going
3 - and the only reason we do it is to prevent the valves
from dropping down....well if the valve is faulty, then the
air pressure is not going to hold it up....but a wad of rope
is not going to fail under any situations
Click on "Valve Seal Replacement" on my page below.
you can get the adapter to do it this way at autozone for a few bucks and it's the best way, IMHO. If the blowby is so much that your compressor can't keep up then there is certainly no point in continuing with a seal replacement! If your valve leaks so badly that the compressor method won't work, then it's time to take the head off anyhow. Cuz you are wasting your time doing seals when you need a valve job instead. A little leakage is no problem; and there is no reason to hurry....just like the rope, the compressor isn't going anywhere, it will keep pressure all day long as long as you have it plugged in! Stuffing rope down a hole is silly! Use the compressed air, it's much quicker and easier.
I don't know, the idea of something happening with the compressor and dropping a valve makes me wary. I've always used the rope...but thats just me.
Using the compressor will also let you know if you have a bad head gasket. I've turned wrenches in dealerships for years and this was the common accepted practice at every place I've worked.
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