Rick,
if the pump is capable enough it may hold the
oil at the same pressure as before. The pump is regulated by the pressure valve.
It has it's reserves.
If it was at the limit already a drop of 10 psi (hot) is acceptable.
There may be no drop at cold, because the pump is bypassed anyway at the preset value of 70 psi, which would be exceeded at cold anyway.
Just do not use L-shaped (Earl's?) fittings to move aroung 90° or Banjos (at the cooler), better use 90° curved bends.
The L-shapes create a bigger loss and the
oil tends to cavitate, because the flow is not laminar.
The old saying was: you loose 10 psi per 10 feet of lining, and 10 psi per 90° "L" and 10 psi in the cooler?.
(10 feet of
oil lines, plus 4 fittings, plus cooler = 60 psi loss???)
What has been your result?
Dominik