Decided to clean and service the stock Denso injectors. Rubber rings get hard and brittle over time and tend to leak. Also the filter baskets might be contaminated over time, especially if the fuel filter is not part of your regular service intervals (which mine S80 lacked…).
I bought this kit of Aliexpress and the quality looks very nice. It contains all the items needed, including a special tool for removing/mounting the filter baskets.
The pictures will speak for themselves (it was needed!).
A very old fuel filter.