603 Injection Pump - Vacuum Control Valve leak
 

When I draw a vacuum on the Vacuum Control Valve (metal box on the side of the IP), from the vacuum supply line coming from the pump, the line not hold vacuum and it bleeds off really quickly. Could this be the way that it is designed? I have read some transmission tuning discussions that seem to indicate that this is the purpose of the vacuum control valve, but I am not really sure.

Any help?