I'm have water flow on the portafilter but no pressure on the brew head.

Checked the pressure with a pressure gauge on the portafilter, and barely registering any pressure. Initially I thought that my grind was too fine compared to the other espresso machine, after costing my grind, shots were all sour and no crema.

Thinking my pump is the problem. Is there a way to check the pressure of the pump directly And not through brew head?

Disconnected the pump and tried to run it , was able to stop the water flow with my fingers and was able to stop it with not much effort.

Yep. Dead pump if you can stall it with your finger.

replaced the pump and added OPV, now my Salvatore is even better than before.

Thank you all for the wealth of information here on HB forums.