fuel pump question

[Sylvester]

hi ... i have a question for you guys... what is the secondary fuel pump for on a mercedes... when the primary pump goes bad it kicks in are what.. i always wonder about this thanks for your help.

[liquiddog]

I've wondered the same thing and searched for the reason when I replaced one of my pumps. I read one explanation that it helps equalize the pressure, but is not like one is a backup for the other. Don't know the reliability of that info.

[ancho]

Pressure or flow requirements are more than a single pump was capable of providing -- but you didn't mention your year/model/engine, which will help you get more specific help here.

[Sylvester]

sorry guys its a 1993 300se w140 3.2l

[oldsinner111]

two for longevity.Less work for one.I was going to update mine with a walboro 255 pump.But now I think I will buy two pumps

[nulu]

Two pumps for volume , for high speed running as all mercedes can go over 125 mph most limited to 150mph