I don't get it....How can it be that the shock absorber cant be repaired?
The bike has 35,000 miles on the clock. I have had a price of about £400 to replace the shock absorber with a used one.
But if the shocks only have a life span of 30,000 - 40,000 miles, a used one is surely not going to last very long.
It seems like such a simple problem; there is a leak on the shock. Is replacing the only option?
I do not want to get rid of the ESA with an aftermarket shock as I like to keep the bike as close to original spec as possible.
Yes, it is odd right. Unfortunately, the stock shock absorbers on the bike are mediocre when new. The ESA feature is nice. When the shock unit leaks its oil, as many do at your mileage, BMW says buy a whole new unit at $$$$. Of course you can do that if you are rich and stupid. The shock itself can be rebuilt of course, and the ESA components reinstalled. Then, you have a like new, but still mediocre unit. Sometimes the ESA components fail, and for that you can also buy a new shock ($$$$) from BMW, or like me, go to ebay and buy a nice used one ($250 and self installed). Since I put so little miles on my 2008 K12GT, the replacement used one will probably last me, and I like being able to adjust from Sport to Comfort when I get tired of scaring myself. I'll be scanning ebay for a used front ESA unit soon. Not a fun installation job.
I understand that you would like to keep the original functionality with ESA. When my R12GSA rear shock failed (oil seal leak), I had it fixed by installing a higher quality Wilburs, shock reusing the stock ESA parts. It works great, and since I use the GSA with wildly varying loads (overloaded panniers and top case), I really needed ESA easy adjustment. I do not know if that option is available with the KGT front shock. If Ted at Beemer... says no, then its probably no.
Many people, realizing that the stock damper units are not very good, use the "opportunity" of a failing shock to upgrade to higher quality units, giving up the ESA for a better handling 300 kg, 150 hp missile. People on this board often comment on how high quality replacement shocks really tighten up the handling. Not inexpensive!
Pay your money, make your choice.
: If I were you, I'd get the stock shock rebuilt, as it is probably just a seal..and then ride until some other overpriced/under-designed time bomb part (ABS, Final Drive, Cam Chain...) fails.