Ford NAA Hydraulic Safety Valve Assembly for sale, 8N638. For tractor models 8N, 9N, 2N, NAA. Mounts on the hydraulic lift cylinder for Golden Jubilee, Jubilee, NAA, NAB. Mounts on the hydraulic pump on 2N, 8N, 9N. **Note: The part you receive may look different than pictured, but will fit and work the same. Replaces: 8N638, NAA984F for sale.