To summary things about hydraulic

1. electric pumps generate 1000psi of pressure, but gauge under gear extension lights shows 3000psi - how come ?

2. when entering cockpit in C&D state parking pressure gauge shows already 3000psi even system is not pressurized yet.

3. when releasing park brakes, parking brake gauge should show zero psi as brakes are released.

4. when using differential braking then parking brake gauge should show differences in pressure between left and right side

Anything else noticed ?