MoS2 added to power steering system, possibly damaged after a violent side skid against a curb, worn excessively having been run too long off a failing crankshaft double pulley or with a sticking relief valve:
Two flushes, first with OMV ATF - situation didn't improve.
Second with brand name ATF and MoS2 additive, steering lightened back to normal.
Dosage was determined per "Some is good, more is better!" principle.