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I have a 2003 C32 that was diagnosed with a bad auxiliary fuel pump. I’m working for a 3rd party so haven’t spoken directly with the mechanic that made the diagnosis. I was expecting to find a pump assembly like the one below.
I pulled the fuel pump from under the passenger side rear seat, and there is no auxiliary pump, just the main. One of the fuel lines connects to the pump output and the other to the bottom of the white surge vessel.
Every description I’ve found in forums references an auxiliary pump that sucks the fuel from the drivers side of the tank over, but there is definitely not one in my car.
I got a diagram from MB that doesn’t seem to show a secondary pump:
Am I missing something here? How does the pump draw fuel from the drivers side of the tank? Has anyone dealt with one of these pumps recently?
Second question: has anyone had any luck sourcing a replacement “pump only” to save having to replace the entire assembly (level sensor, surge tank, etc) There are a number of threads on this topic, but most of the links are dead now and I was hoping to find someone with recent experience.
Here are a couple photos of the pump in the tank and disassembled.
Thanks in advance, I’ve been reading a lot of old threads and this forum has been a great resource.
I have a 2003 C32 that was diagnosed with a bad auxiliary fuel pump. I’m working for a 3rd party so haven’t spoken directly with the mechanic that made the diagnosis. I was expecting to find a pump assembly like the one below.
I pulled the fuel pump from under the passenger side rear seat, and there is no auxiliary pump, just the main. One of the fuel lines connects to the pump output and the other to the bottom of the white surge vessel.
Every description I’ve found in forums references an auxiliary pump that sucks the fuel from the drivers side of the tank over, but there is definitely not one in my car.
I got a diagram from MB that doesn’t seem to show a secondary pump:
Am I missing something here? How does the pump draw fuel from the drivers side of the tank? Has anyone dealt with one of these pumps recently?
Second question: has anyone had any luck sourcing a replacement “pump only” to save having to replace the entire assembly (level sensor, surge tank, etc) There are a number of threads on this topic, but most of the links are dead now and I was hoping to find someone with recent experience.
Here are a couple photos of the pump in the tank and disassembled.
Thanks in advance, I’ve been reading a lot of old threads and this forum has been a great resource.
It's been done! If I were you I'd replace them both at the same time. It cost me around $160 for both pumps inc shipment instead of paying $1000+
It's straight forward! But be prepared, getting the plastic fuel hose off the pumps is bit difficult and it broke on me! I ended up replacing the plastic fuel lines with a submergable hose from NAPA! You can't use just a regular hose other wise it'll degrade and melt in the tank!! I'd personally order that hose at napa while waiting on pumps also get bunch of fuel line hose clamps!
You can grab the part numbers from this thread!
Hope this helps!
08-27-2021, 01:00 AM
