SL/R129: New Fuel Pump and Filter Leaking
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Joined: Sep 2022
Posts: 155
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From: Ohio
2005 S55 AMG, 2001 SL500
New Fuel Pump and Filter Leaking
I own a 2001 SL500 and had a new fuel pump and filter installed about a month ago. Car seemed a bit sluggish from the get-go, got much worse as time went on, and I have now discovered a pretty serious fuel leak behind the driver's side rear wheel which has me totally stumped considering the location of the pump and filter. It begins when the key is put into position 2 and picks up steam a bit when the engine starts and stops within one minute of shut down. (I'm assuming that's residual fuel that's pooled somewhere). Botched replacement? Or am I up against something else?
Just went out and loosened the filler cap and heard a big whoosh. Which seems to have starved the fuel lines as the car will no longer start. Side note: Fuel gauge is somehow affected as is the MPG indicator on the dash. Fuel gauge pegged at full after fill-up prior to install now shows 3/4 full, and the MPG indicator now swings wildly, especially under light acceleration. Thanks in advance.
Just went out and loosened the filler cap and heard a big whoosh. Which seems to have starved the fuel lines as the car will no longer start. Side note: Fuel gauge is somehow affected as is the MPG indicator on the dash. Fuel gauge pegged at full after fill-up prior to install now shows 3/4 full, and the MPG indicator now swings wildly, especially under light acceleration. Thanks in advance.
Last edited by CICBarkeep; Jun 8, 2025 at 05:17 PM.
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Joined: Oct 2017
Posts: 368
Likes: 73
SL600
The fuel pressure regulator is installed inside the fuel filter; any excess fuel flows back from the filter to the tank on the passenger side. There are a total of four connections on the filter; I would check that all the hoses are connected to the correct connection. OEM comes from Mahle, Bosch, and MANN; I wouldn't install an unbranded product.
