Fuel pumps

[A Khan]

Last week I replaced my 91 300E fuel filter and accumulator. After searching this forum I bought a Bosch filter and installed it. Everything was fine until yesterday. I noticed a buzzing sound coming by the fuel filter and pumps area. I never heard this buzzing noise before. Should I have done something differently (e.g. the way hoses are placed by the the filter) when replacing the filter and accumulator?

Or maybe I should have bought a Knecht (fast lane part# E1000-12143) filter since that was on my car when I replaced it with Bosch (fast lane part # E1000-29298).

It is also possible that this is just a coincidence and the fuel pumps are dying out. If this is the case any hints on replacing the fuel pumps. The part number I found in fast lane s Bosch part # E3000-95322. Is this the correct pump I should buy.

Thanks