Since the 1960s, manufacturers have made automotive coolant hoses using EPDM (ethylene propylene rubber) aka synthetic compounds. ECD (electrochemical degradation) was a common occurence where the hose, liquid coolant (ethylene glycol antifreeze and water), and the engine/radiator fittings form a galvanic cell which cracks the hose.


More recently co's developed an electrochemically-resistant coolant hose using a new EPDM formulation, so perhaps that's what the forum was discussing (?)