Originally Posted by Al_The_Man  I wonder how they lap the blades in at the factory?
The fact they are made of such a friction free material, I would think it would take too long to bed them in by running.
Unless they are precisely machined?
Al. |
This is probably a situation similar to running in the cylinders and piston rings in a car engine. You have two not-completely-perfect surfaces rubbing against each other and the imperfections in each polish each other to a smoother state. When you replace the piston rings it is necessary to hone the cylinders to get back to two non-perfect surfaces once more bedding in. If you do not do this the new rings do not run-in correctly. I would suspect that if the vanes were replaced in one of these pumps a similar thing would have to be done to the housing, rough it up so you are replicating the original bedding-in conditions.