seal tests

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Jan 29, 2006
We often discuss oils in relation to metal wear. For the last 27 years my only passenger-car-engine issues have been seals. Are there any standard seal-lifespan tests that are used to evaluate oils? I am curious about both wear at the elastomer/metal interface as well as non-wear (shrinkage, hardening, softening, expansion, cracking, ect.). If I "knew" that a given oil met specifications other wise, I would use seal lifespan as THE deciding factor in my oil purchases. This parameter is more important to me then all other "beyond spec" parameters. Problem is, I don't have a way to evaluate this parameter.
Seals go bad for three reasons,1) the seal is overheated, 2) the seal gets a varnish or sludge build up that prevents oil and oil additives from reaching it, and 3) the seal is gradually lapped away by contaminants in the oil. A good ester based synthetic like Redline will take care of the first two problems. A bypass filter will take care of the last problem and help with the second.My observations over the last decade indicate, but do not prove, that ester based synthetics improve seal life.The rubber/plastic/teflon seals always seem pliant, springy, and uncracked with Redline. Scientific tests prove that a good bypass filter will also extend your seal life.

Thanks for the input. Based on several cars owned by family and friends, I have begun to think that teflon oil additives reduce the lifespan of seals. Perhaps the "lapped away" phenomenon is accelerated when solid contminants are purposely added. Most teflon users that I know use it at one fifth regular dose, but they use it continuously (as opposed to at fixed intervals).
At work I am sometimes involved with wear testing as related to seals. I'm not involved in the compatibility or hardening parameters measured on the seals, but I do know that contaminant debris and filtration is a factor in seal performance.
carock, Kestas,

Thanks for the input. It sounds like many of the seal lifespan parameters are known. However, it also sounds like there are not "standardized" or "sanctioned" tests that reduce seal performance (nor oil performance in regard to seals) to a number or grade.

Any additional input is still welcome and wanted.
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