Based on our shop experience specializing in heavy-duty brakes since 1985:

• Van Chassis Vibration: Astro and Safari engine bays are tight and prone to heat soak. Our exclusive rust-prohibitive finishing process protects this cast iron unit from environmental corrosion.
• Fluid Contamination: These hydraulic systems are shared with the power steering. Always perform a complete flush with fresh, high-quality fluid. Sediment from a worn pump is the primary cause of hydroboost seal failure.
• Pedal Return Issues: If your brake pedal is slow to return, check for air in the hydraulic lines. Follow our guide below for the specific bleeding procedure required for these GM van platforms.