B737-700 First Officer reported they received Low Pressure lights for the engine driven and electric hydraulic pumps on the A system during departure. The crew noted the hydraulic quantity was at 64% down from 90% during pre-flight. The lights extinguished but the quantity kept decreasing; so the crew decided to return to the departure airport after discussing the situation with Maintenance Control.

Narrative

Immediately after retracting the landing gear; we received 'Low pressure' lights for both the engine driven and electric hydraulic pumps on the A System. The condition continued for roughly 30 seconds when the Low-pressure lights extinguished and the system stabilized. We noted that the hydraulic quantity had dropped from roughly 95% noted during pre-flight to roughly 64%. Since the lights had extinguished by this point; we elected not to run the QRH but rather we noted the steps that would be taken; should the condition re-manifest. We continued our climb and the Captain turned flying and ATC COMMs over to me; as he left to establish COMMs with Dispatch and Maintenance. As I continued the climb; I noted that the hydraulic quantity was slowly decreasing at a rate of approximately 1% quantity every 90 seconds or so. The Captain relayed this information to Maintenance Control and it was decided that a diversion was needed. Given our close proximity to ZZZ; we decided to return to our point of departure. In our descent into ZZZ; we noted that the quantity was getting close to 50% so we elected to extend the gear approximately 30 miles north of the field. Upon extension; the system pressure came up to approximately 65% and stabilized. Because of this; we elected not to declare an emergency as the system quantity was no longer dropping and the landing gear was down and locked. It was noted that an overweight landing was going to be necessary given the deterioration of the A Hydraulic Fluid. We consulted the handbook and it was noted that a brake cooling calculation would not be necessary. The Captain made an outstanding touchdown and we proceeded to the Gate without incident. Upon post-flight inspection; we noted a significant amount of hydraulic fluid still flowing from lines off of the port side system.