valve seals on a 390

[dmraymond]

Is it possibnle to change seals with out taking off the head? are there any tricks that I should know? thanks for any input.     57ford

[RAWms]

I remember a trick where the cylinder in question is positioned at the bottom of the stroke, pull the plug and feed in a cord/rope.  Then move the cylinder up to compress the cord against the valves holding them in place.  Do the R&R you want and reverse the process.   I have never done this but would probably consider if need be.  Good luck, r

[shopratwoody]

I have done this on several engines thru the yrs using air. Put air to the cyl to keep the valve from falling in
take the keeper and retainer off and put on new seal. Hopefully you have the stock type umbrella seals. The good
ones (PC etc) are harder to remove. The newer seals last longer than the old ones....better material.
good luck, Ron

[Glen Henderson]

It was standard practice in the 60's to replace seals without removing the heads. The tool to air up the cyl is very simple to make, just take an old spark plug and break the tip and top end off it keeping just the treaded base. Braze a male air line fitting into the  base and plug it into a regulated air line. 40 to 60 psi should do the trick. There are several tools on the market too use to compress the valve spring for removing the keepers, but with a little work and trial and error, you can fab up one.

[shopratwoody]

K.D. makes a nice little spring compressor and it's reasonable enough. You can't use the lever or bar type like
for a Chevy cause you have rocker shafts instead of individual studs that the tool fits on. If it has crip on
seals like PC that are shot just remove them with pliiers and replace them with the stock umbrella type.
It'll stop smoking, especially on the idle.
Good luck, Ron