This paper will deal exclusively with automotive coolant leaks caused by improper joint design. It is intended to help prevent frequent design errors by using variation reduction tools.A systems approach to sealing coolant carrying joints fastened with hose clamps has been adopted. The systems method looks at each component in the joint and its relative importance to the systems sealability. Revised dimensioning, machining, and assembly practices have been recommended to remove joint to joint variation.Successful implementation of spring clamp technology (continuous force clamps) has, in some cases, eliminated the need for conventional screw type clamps. However, adjustable clamps requiring a torque specification (i.e. worm gear, double wire, etc.) may be still required for special applications. More design and validation guidelines can be found in SAE Recommended Practices Document J1697.