Add Windshield Wiper / Washer Fluid: 2025 GMC Sierra 3500 HD Denali Ultimate 6.6L V8 Turbo Diesel

Adding windshield washer fluid to your 2025 GMC Sierra 3500 HD is a fairly straightforward process. The video above shows you where the window washer fluid reservoir is located in your Sierra 3500 HD, 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!