I was only on the aircraft type for about 7 months and that was 2 years ago....
That being said, the thread has a generic title for 737. I flew the 737-200 series. I believe that my earlier statement is correct but welcome any corrections if you feel I am wrong that A-system is two engine driven hydraulic pumps, while B system is two electric pumps. No overheat indication for A system pumps. Both types have case drain fluid cooling, both systems have heat exchanger cooling in the fuel tanks and my previous statement was correct.
Can anyone confirm.
Later model 737's. Don't know a thing about them.