First thing first so not to disturb others that follow this newsgroup religiously or not. Question is about 1988 VW Fox wagon GL 1.8L SOHC CIS-E.
Item: reservoir/filter runs between fuel tank enclosed transfer pump and primary fuel pump. The line from the engine compartment and a line to the fuel tank also have lines attached to this item. Bentley manual calls the item a fuel reservoir. VW calls the item a fuel filter. Bentley manual says the item is for purpose of storing fuel for surges as the primary fuel pump may overcome the transfer pump's capacity. As I'm sure you've ascertained, there's 4 (four) lines on this item. I purchased a replacement, as the currently installed item is leaking very slowly. The currently installed item is painted red. I cannot observe its, if any, contents. The new one (no paint) has an obvious filter within it observing from one line input. Also observable is a cap of sorts with some kind of glue/adhesive where two (2) lines are on the new item. The other two (2) lines are on the remainder of the new unit/item.
So, I'm a bit confused here regarding the Bentley manual, and the obvious naming of the item by VW as a filter. If its a filter, maybe, just maybe, the item should be replaced a bit more often as its not listed in the maintenance section of the Bentley manual. I've also noticed in all the questions I've asked here indicating all relevant information that no one indicated this as a filter. In the past, I've had a problem with a rusted out internally gas tank as another example. No mention regarding this as a potential problem. All this I found on my own, without many frequent repliers help or responses.
My question is: why does the Bentley manual refer to this item as a reservoir, no mention of internal filtering? Case in point is the fuel distributor. The hollow bolt on a new model has a filter screen, and recommends replacement with a bolt without such a screen. Yet, says nothing about the filter in the item?