I have a 98 accord with 137k miles 4-cyl. Is it necessary to replace the large o-ring for the disributer cap? Will it ever leak? I opened it up and it looks ok. I replaced the cap and rotor button, but not the o-ring. Should i be concerned?

 

If your're in doubt lube up the oring with Dielectric Compound. Works like a champ you won't be disappointed.

 

if u are talking about the cap seal between cap and distr housing there is nothing to worry, there is nothing to leak....

 

One of my services is steam cleaning engines for safety inspection requirements in my area, of course for this reason I try not to spray too much water near the dist and plugs in the head (hemi style) but I have noticed that caps without seals tend to misfire more than others, but this of course is due to the engine cleaning which most folks dont do. I may even vote for no gasket in this type since Honda distributors have a tendency to leak oil from the internal shaft seal and it should start to leak out sooner with a not so tight fit at the cap / dist mating surface.