Is it necessary to replace the valve seals when swapping out springs? 92 305 TPI Car doesn't smoke or lose any oil and if it ain't broke...

I'm sure I don't HAVE to replace the actual seals, but I read (searched) that there's an O-ring between the locks and the retainer? I never knew where those orings went that came in the gaskets sets.

 

No you don't HAVE TO replace the seals; but it'd be pretty dumb not to. At least, it would for me, be cause AS SURE AS I didn't, it would start smoking the next day. That's my kind of luck. Maybe yours is better than mine, maybe even so much better than you can COUNT ON IT; you'll have to be the judge of that.

They're cheep. Change em out.

Yes the O-rings go on the valve stems above the retainers, and get pushed down into it by the keepers. It doesn't really do much. If you have REAL seals, don't bother with them.

 

Agreed- they're cheap and they're staring you right in the face once you've got the old springs out. The material they're made from gets hard and brittle over many many heating and cooling cycles of the engine (not to mention the mechanical wear on them). They don't last forever and seal technology from ~1990 is not what it is today.

Like SOFA said, it would be your luck that the car stars blowing blue clouds on startup a couple days after you button it back up. Don't do the job twice.

Later motors like yours the factory started using positive-style seals that clamp around the top of the valve guide boss. They do plenty good by themselves- you don't have to replace the additional o-ring up near the top of the valve stem unless you feel like it.

 

Thanks, that's what I figured. My head guy at the shop I worked at always liked to use the positive seals.

As far as my luck goes... typically as soon as I do something as a preventive measure, that's when things go wrong.