Hey,
Maybe the time-to-failure is inversely proportional to the cost of the
replacement. Thus, the $4.00 ball valve will last several orders of
magnitude longer than the $30.00 replacement valve. In this scenario, if the
replacement valve cost $100, it would fail instantly upon installtion!
Just to be clear, all of the failures that I've seen were on valves that
were clearly original items and most of them fail at something like age
20 or so.
They do seem to fail more often when they've been stuck in one position
for a long time (like "off" all summer) and then turned on full...
My car lost the original valve at around age 21 years. The replacement, a
"used" item lasted around six months, much of that time the engine never
ran! I put in a new one from one of the "big three" and that one's lasted
at least 4 years so far...
Applying the inverse proportion law stated above, it appears that the theory
is flawed. The first valve should have failed _at the dealer_ because the
car was purchased for something around $6000 dollars. Thus, the valve
should have failed literally milliseconds after purchasing the car.
However, that was not to be the case and it lasted just about 21 years.
The second unit was free, I took it from a friend. However, it did fail
within a week of my having reimbersed said friend to the tune of $15 or
so. So there is some semblance of adherance to the theory...
I think the one in there now was a "free premium" from Charles, so it
should last forever.
Or 20 years.
Whichever comes first.
;-)
rml
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