Professional software development, amateur BMW tinkering, old arcade game stuff


E31 power steering fluid CHF11S

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.


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