Product: Windshield Washer Fluid Reservoir Cap / Water Tank Lid Fitment: Cadillac CTS 2008–2017 Key benefits Restores a tight seal to the washer fluid reservoir to prevent leaks and overflow during driving. Simple direct replacement for worn, cracked, or heat‑damaged caps to keep washer fluid contained and contamination out. Durable plastic construction designed to withstand normal under‑hood conditions and road vibration. What it does Replaces the windshield washer reservoir bottle lid (water tank cap) to maintain proper fluid containment and system function. Keeps dirt and moisture from entering the reservoir and helps prevent fluid loss. Compatibility Specifically designed to fit Cadillac CTS model years 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017. Material and performance Made of durable plastic for reliable sealing and long service life under typical engine‑bay conditions. Intended as a replacement cap when original units fail due to heat exposure, material fatigue, cracking, or other damage. Installation Quick, no‑tool swap: remove the old cap and press the replacement onto the reservoir neck. Inspect the gasket and seating to ensure a proper seal after installation. Use scenarios a cracked or warped cap after prolonged sun exposure causes fluid leakage. Restore a missing or damaged cap following minor front‑end service or collision to prevent contamination of the washer fluid. Routine maintenance upgrade when the original cap shows signs of fatigue, preventing future leaks and ensuring reliable wiper washer operation. Notes Confirm vehicle model year before to ensure compatibility with Cadillac CTS 2008–2017.