320 SL Fuel Pump

[fattogatto]

Developed a fuel leak from right rear. Wife forced to take it to dealer. Dealer quickly says $450 for a fuel pump, 2 seals, and some "cheap line." Only 46,000 miles on a 1996 car. Not sure if this chassis model has one pump or two and I am out of town without chassis number. Tried "eautorepair.net" to try to find a schematic as to whether the pump(s) is/are internal to the tank or not. IMO that website is worthless. Cost me $7.99 to find out. Logic tells me that if the pump is leaking then it is external to the tank, otherwise it would be leaking into the tank, no? In my experience these pumps do not usually leak: they may fail, but not leak. BTW, this dealer is notorious for simply replacing the offending part without checking its operation. They are usually quite perturbed when you insist on keeping the replaced part, often saying there is a core charge.

Two questions. First, assuming pump is external to the tank, how difficult is it to acces and replace if need be? Second, other than at a fitting, any idea how these pumps can leak?

Thanks