Pump pressure ?

[Lee Thompson]

The pressure reading I get off the drivers side port--is that directly off the pump. Reason I ask is that if I unhook the cable @ the throttle body and with rpm @ 2200 in neutral the pressure goes to 200 but promptly fall back toward 100. Fresh rebuild but something not right. With the selector in manual low and power braking the pressure goes to 240. Thanks

 

[mikestertwo]

Yes, that is the tap for line pressure directly off of the pump. If you disconnected the cable off of the throttle body you have seated the exhaust check ball for your throttle valve, assuming you left it in, so the pressure will not control properly. You cannot check pressure that way. Your pressure in manual low looks right. It will depend on what size spring you have on the pressure control valve in the pump and the size of your boost valves.