Re: Vacuum Lines, Windshield Wipers

Posted by HH56 On 2024/5/31 16:03:37

Thanks for posting something in writing and an actual factory recommendation on testing the vacuum side of fuel pumps.. That test should be made available in other forums because it holds true for all cars with dual action fuel pumps.

The typical dual action fuel pump vacuum side does not have the volume to operate the wiper at normal speed but the whole purpose of an aux supply is to make sure some vacuum is available to keep the blades moving. Any dual action pump should have enough vacuum power as measured in mm/hg to keep the motor moving slowly as the test suggests. Without the aux supply a large sustained load on the engine or sudden mashing of the accelerator to the floor if you want to pass some cars cuts engine vacuum to almost zero and blades will stop if something is wrong with the extra supply.