Hello,
I find that the average lfe of any manufacturer's pumps can vary dramatically.
I have replace the BMW M30 w/p with boring regularity, average of three years on every car(3.0,525&635).
On Volvo 240, it has been done every 6 years or so and on an Opel Manta A, the pump would expire every 2-3 years.
Mercedes has been longer lived, the W124 260E pump ran to 180,000 miles(and 15 years) before the o-ring sprang a leak, BUt due to the difficulty in R&R, a new Laso pump was fitted, W115 200 original pump replaced after 27 years and unknown mileage(had to knock it out with a hammer!), the vanes were worn down and the thing was rattling, but only replaced when it began spewing coolant onto the road.
Having said that, the 260 will probably spring a leak this evening.................
Have a good week.

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Nachi11744