maybe it primes for the vac. motor before you start up the motor? You really need to find where the line goes on the inside of the cab and let us know. It is obvious that you can only pump it when not driving


Poets Seat Auto
Appraisals, Parts, Service
Past: General Motor's Master Technician
Member: Northeast Chevy/GMC Truck Club
Phone Number: 413.774.5856
Collector of: 1951 Army Chevy Burb barn door,53 GMC COE,two 1934 Chevy Truck,1935 Chevy Army Truck.1950 Gmc Suburban clamshell these are just my chevy/gmc trucks.