Stray electrical currents can cause leaks in cores. Take care to make sure that all electrical is properly grounded throughout your whole system, or it could end up that your core is the path of least resistance and will in turn void your warranty.
Damage not related to craftsmanship
When removing the old radiator take note of which bolts go where. It is imperative that the correct size bolts be put in the correct place. Too long of a bolt could cause damage and make your warranty void.
Over pressurized system
A quality radiator will do it's job best when part of a quality system. An over pressurized radiator is usually the first sign to a larger mechanical issue. Most often it is the first sign to a blown head gasket. More rarely it is the result of a worn radiator cap.
Damage to the filler neck or hose connections as a result of water, steam, recycled anti-freeze, or other non-approved additives will not be covered.
Coolant that appears rusty is contaminated from oxidation or possibly mixing different types of coolant causing premature failure
Corrosion from chemical catalyst
Fertilizers and other chemical catalysts accelerate deterioration and are not covered by warranty.
When installing the new oil cooler fitting, take care not to force the thread. If not aligned properly the threads could strip and void your warranty.
Any shipping damage will be filed with the carrier and needs to have a claim filed separately and not in connection with warranty returns. When returning product take care to package properly.