You may have a restriction.

I don't know where your pressure sending unit is, but on my '96 E, it's after the dryer. Debris in the dryer causing a restriction will fool the computer into thinking there is not as much high-side pressure. That causes three effects: insufficient cooling, no auxiliary fan, and venting of refrigerant from the compressor relief valve.

I notice that you did not replace the condenser. That's a possible cause. You can't really flush a parallel-flow condenser and have any hope at all of getting it clean.