An aftercooler mounting and sealing system for use with an internal combustion engine is disclosed including an intake manifold (14), a distribution manifold (16) disposed downstream of the intake manifold (14), and an aftercooler (12) clamped between the intake manifold (14) and the distribution manifold (16). Resiliently compressible U-shaped seals (32, 34) are provided between the inlet (24) of the aftercooler (12) and the intake manifold (14) and between the outlet (26) of the aftercooler (12) and the distribution manifold (16) to effectively seal against leakage of charged intake air from the manifold joints. The clamp load across the resiliently compressible seals (32, 34) is selectable independent of the clamp load across the intake manifold (14) and the distribution manifold (16).