Adding windshield washer fluid to your 2001 Ford E-350 Econoline is a fairly straightforward process. The video above shows you where the window washer fluid reservoir is located in your E-350 Econoline, how to remove the reservoir cap and how to refill the windshield wiper / washer fluid. The nice thing about adding windshield washer fluid is that you can't overfill the reservoir - once it's full, you can stop adding fluid!