returned item damaged

[pete1979r]

i sold a set of mtb suspension forks on ebay (air spring) the buyer reported clunck and oil leak hence the reason for the return. on return arival it would apear the cause of failure is due to the over preasurisation of the fork resulting in the seal blowing and thus the oil leak, this senario is documented in the forks technical documentation. on inspection the fork now will not hold air hence a repair is now required. the fork was recently serviced before sale, all other defects / condition was stated at the time of sale as there is no point of not being honest. where do i stand?

[captain*obvious]

Sorry, but you're on a hiding to nothing.

The SC32 has seal issues as an inherent design fault, something as simple as a steep decline can make them pop. 

Your buyer could have damaged them, but you'll never convince eBay that the very reason they want to send them back, (ie, that they're faulty) is their fault.

Replace the seals, relist and hope that the next buyer understands that as far as bike forks go, these are high maintenance and need checking once a month at least.

[pete1979r]

And there in lies my problem.
1 the buyer accepted this when bid (unless they hadn't done there homework, with the fork being unconventional you would have expected them to have at least have google about).
....However....
2 the buyer in this case states he's been through 4 sets of these forks by admission which is why I was directed to misuse.