Quote:
Originally Posted by jamesqf
Well, you win some, you lose some. Don't have enough personal experience to say, but my guess is that, averaged over the whole fleet, the savings on maintenance &c of hydraulic PS would more than make up for the cost of the rare but expensive EPS failure.
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Not that rare, actually. As early cars with EPAS get older, the failure rates go up. It's already a big talking point with early Honda Fits, which makes for good business selling reconditioned surplus racks!
Whether the failure rates would be different with similarly-specced hydraulic systems, I don't know. Yes... if you ignore a hydraulic leak for long enough, you'll need to replace the entire hydraulic rack, too... but it rarely gets that far.
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Over the past several years, doing slalom tests, I've experienced overload and loss of assist with many electric power steering systems... sometimes on the second or third turn of the wheel! But new hydraulic systems, seemingly sized, also, for fuel economy rather than heavy duty use, also experience a loss of assist quite easily... as cavitation starts within the hydraulic rack the moment you have to saw at it. Not great in an emergency.
Of course, if the rack is properly built, it should last a long time. Took us two dozen straight slalom runs to heat up the electric rack on the new MINI to the point where it lost assist. After that, let it cool down... no problem. Most hydraulic racks, even on sports cars, will see fluid cavitation with use that extreme, too.
Again... this seems driven mostly by fuel economy requirements (which force manufacturers to spec steering systems with less parasitic load) than anything else. Personally, I think crazy economy requirements will eventually force a return to completely manual steering racks. At which point:
Quote:
Originally Posted by jcp123
we'd have auto journos breaking out the champagne
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