While I was replacing the fuel filter during the weekend, I noticed that there are two things next to the fuel filter. Their look similar to the fuel filter but smaller in diameter. One is on the left of the filter and one is on the right. One of them (or both?) has electric wires go into it. Can anyone tell me what those are?

Fuel pumps
 

Those are your fuel pumps.

I have two fuel pumps?
 

Hi, Arjay:

Thanks for the quick reply. Wow, I have two fuel pumps. I suspected that one of them is the pump. I did turn on the engine and went down there (to check for any gas leak after I replaced the fuel filter). They didn't make a lot of noise. So I guess my fuel pumps are OK. In the future if one of the pump is bad, should I replace both?

Fuel Pumps
 

My '95 C280 has only one pump, so I couldn't answer your question about changing one or both. My guess would be to perform appropriate tests (fuel pressure, leak-down pressure, etc.) and replace only what is required.

Fuel filter.
 

Hello Han& Arjay,

Have been contemplating replacing the fuel filter on my '97 c-class which is located under the carriage in front of the tank. Seems space is at a premium there. Did you find ti hard to do at all or is it just a straight forward DIY job?

Thanks for your advice.

Also, have any one of you replaced the coolant yourself? If so, could you point out the drain plugs' location - I suspect there are plugs on the radiator and the block. I would rather undo the hose than toucjing the radiator plug but do not know where is the one on the block.

C.F.

A fuel pump has a pair of wires running to it. if only one of the "things" next to the filter has wires, the other object is probably an accumulator, with helps keep the fuel supply pressure steady when the fuel pressure regulator is making changes to the fuel pressure at the injection side.....Gilly