A previous post talked about the replacement of the brake booster pressure accumulator. The possible reason for the failure of that component became apparent when I examined the power steering fluid (the same pump/fluid drives the brake booster as well as steering and if present self levelling rear suspenion).
It’s red! Most likely a previous owner/mechanic dumped regular ATF in there rather than CHF hydraulic fluid. There’s a good chance this damaged the pressure accumulator diaphram over time.
CHF11S should always be a strong green colour, as should the older CHF7.1 used in the E32.