Though Ford could have proceeded with the formal recall hearing, fearing additional damage to the company's public reputation the company agreed to a "voluntary recall" program.[106] On June 9, 1978, days before the NHTSA was to issue Ford a formal recall order, Ford recalled 1.5 million Ford Pintos and Mercury Bobcats, the largest recall in automotive history at the time.[107] Ford disagreed with the NHTSA finding of a defect, and said the recall was to "end public concern that has resulted from criticism of the fuel systems in these vehicles."[108] The Ford recall placed a polyethylene shield between the tank and likely causes of puncture, lengthened the filler tube, and improved the tank filler seal in the event of a collision.[109]