1 x Genuine CNH Water Pump. This part fits the following models. 6640 – 4 CYL AG TRACTOR 40 SERIES (11/91 – 01/98). 6640O – 4 CYL ORCHARD TRACTOR 40 SERIES (11/91 – 01/98). 5640 – 4 CYL AG TRACTOR 40 SERIES (11/91 – 01/98). 7740 – 4 CYL AG TRACTOR 40 SERIES (11/91 – 01/98). 7740O – 4 CYL ORCHARD TRACTOR 40 SERIES (11/91 – 01/98).