How is it the the japanese can make an auto air pump which NEVER has to be replaced during the life of the car and yet aircraft are stuck with these stupid dry vacuum pumps?
They are mostly wet vac pumps especially in the case of diesels, where these pumps provide the vacuum for the Brake systems. They are usually on the back of the alternator. They appear to run forever without intervention.
I have had wet vac pumps on my 185s. They can be as unreliable as dry pumps. They give no warning when they are about to fail and are very expensive to O/H.