Frequently Asked Questions About GMC TopKick Truck Air Tanks, Wraps & Mounting

What size air tanks are compatible with GMC TopKick C4500, C5500, C6500, and C7500 models?

GMC TopKick trucks typically use air tanks ranging from 11" to 13" in diameter, with the most common being 11" x 37" or 13" x 37" aluminum tanks. C4500 and C5500 models (2003-2009) generally use single or dual 11" diameter tanks, while C6500 and C7500 models often require larger 13" diameter tanks due to increased air system demands. Always verify your specific model year and air system configuration before ordering, as tank sizes can vary based on original equipment specifications and whether your truck has air brakes, air suspension, or both.

How difficult is it to install replacement air tank mounting brackets, and what tools are required?

Installing air tank mounting brackets typically requires intermediate mechanical skills and takes 2-4 hours per tank. You'll need basic hand tools including socket sets (typically 3/4" to 1-1/4"), wrenches, and a torque wrench. Most installations require drilling new holes if upgrading from steel to aluminum tanks or changing tank positions. Common challenges include dealing with rusted original hardware, ensuring proper clearance from exhaust components, and maintaining correct air line routing. Professional installation is recommended if you're uncomfortable working with air brake systems, as improper installation can affect brake performance.

What's the difference between steel and aluminum air tanks, and which is better for my TopKick?

Aluminum tanks are the preferred choice for most TopKick applications due to their corrosion resistance, lighter weight (approximately 50% lighter than steel), and longer lifespan in harsh conditions. Steel tanks are more budget-friendly initially but prone to internal rust and condensation issues, especially in humid climates or with frequent short trips. Aluminum tanks typically last 15-20 years versus 7-10 years for steel. The weight savings of aluminum tanks (20-30 pounds per tank) also improves payload capacity and fuel economy. Consider aluminum if you operate in salt-belt states or need maximum longevity.

Are air tank wraps necessary, and what material options provide the best protection?

Air tank wraps are highly recommended, especially for trucks operating in winter conditions or on salted roads. They protect against road debris, salt spray, and moisture that accelerates corrosion. Vinyl wraps offer basic protection and are available in chrome or painted finishes to match your truck's appearance. Heavy-duty rubber wraps provide superior impact resistance but may trap moisture if not properly ventilated. Stainless steel heat shields are ideal when tanks are mounted near exhaust components. Most TopKick owners find vinyl wraps offer the best balance of protection, appearance, and value for typical applications.

What are the signs that my air tanks need replacement, and can I replace just one tank?

Replace air tanks immediately if you notice excessive rust (especially internal), pinhole leaks, damaged mounting tabs, or if water drainage exceeds normal amounts (more than a few ounces daily). Bulging, dents deeper than 1/4", or any cracks require immediate replacement. While you can replace a single tank, it's recommended to replace both tanks simultaneously on dual-tank systems to ensure balanced air system performance and avoid mismatched tank conditions. Tanks installed at different times may have different moisture accumulation rates, potentially causing uneven brake response or premature failure of the newer tank.