https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/12561/2.html

Most attempts to revive a vacuum wiper motor with various chemicals work for I time then fails again. Whatever liquid you force into the wiper motor is sucked back into your engine so be careful what you use.

The leather or leather-like material of the paddle that fits the contour of the housing ages and becomes stiff. The material needs to be somewhat flexible and is coated with a type of grease. The paddle must seal well in order to provide maximum torque to move the wipers. There is an art to rebuilding the paddle. The original repair kits are hard to find and many restoration businesses make their own parts. They do not sell kits.

Last edited by buoymaker; 08/18/2022 10:24 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."