My 95 960 seems to have multiple fluid leaks that I am trying to troubleshoot.

First, there is a coolant leak. I had the heater core hoses replaced, and the leak was still there after hose replacement, although slower. I tightened the worm drives clamps on the hoses more, and the leak slowed, so this may be the leak source. How careful need I be on tightening these hoses? Concerned it may be the upper rad neck. Is a full on pressure test the better way to go now?

Second, I have an oil leak in the general area of the oil filter. I changed the oil and filter, cleaned the mating surfaces, and made sure the filter was tight, but the leak continues. What is above the oil filter or in that area that could be the source of the oil leak. Does the oil filter screw into the oil pump?

Third, I have a brake fluid leak. It comes from under the master cylinder. I think it may be the brake portioning valve. Any ideas on how to be sure here?

I will DIY it with a mechanic friend, but I generally have to diagnose the cause and buy the part for this arrangement to work. Problems piling up with this car. Ideas appreciated.