The utilization of adhesive bonding has attracted a growing concern in the field of automobile manufacturing, which requires the development of easy disassembly techniques for the reuse and recycling of body materials. In this study, we examined the immersion of adhesive joints in pure water and sodium chloride (NaCl) solution as a pretreatment of such a separation process. Regardless of the adhesive types, the immersion treatment increased the water content of adhesives, which led to their plasticization and volume expansion, determined by DSC and FT-IR analyses. Along with this, the tensile strength, dielectric strength, and volume resistivity of adhesive were found to greatly decrease, and this decreasing trend was more visible with lower NaCl concentration. Overall, our results suggested that immersion treatment can be a promising pre-treatment for an easy disassembly process with manual dismantling or electric pulse method.