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Hi everyone. I searched the forum and Google to no avail. I have smell of fuel from the driver side rear of the car. I checked for leaks on the ground but nothing. It is strong enough you can smell it in the cabin. I check under the rear drivers side in front of the tire as there is a cover there that felt a little damp and had a little gas smell. I am assuming fuel lines are under there. Anyone have this issue before and what was the cause? I didn't see any recalls for this car when it comes to fuel leaks. Thanks for any help.
I had the same issue with my 2012, it ended up being the fuel sender unit under the back seat on the driver side. the housing had a crack making fuel drip down the fuel tank. I believe mercedes might fix it as there was a recall for the previous gen cls but I fixed it myself and don’t know how true that is.
I had the same issue with my 2012, it ended up being the fuel sender unit under the back seat on the driver side. the housing had a crack making fuel drip down the fuel tank. I believe mercedes might fix it as there was a recall for the previous gen cls but I fixed it myself and don’t know how true that is.
Thanks for the reply. How hard was it to do and how long did it take you? Is there one or two fuel sending units? I might reach out to Mercedes to see what they can do for me.
It’s not a very hard job, the hardest part is loosening the rings that seal/attach the fuel units to the tank. It took me about two hours but now i could do it in 30 mins. I removed both seats, took off the covers under the seats. Unplug connectors and hoses, be careful because the hoses are under pressure and will spray fuel for a split second, have a rag over the hose you disconnect. You remove the hose by pinching a small clip. Take off the two retaining rings. There are two hoses that will connect the fuel units together. I started on the passenger side and tied a wire to the end of it so that i can pull the same wire back with the new assembly and not fish for it in the tank. Do everything in reverse order. I cycled the ignition to prime the pump a few times before starting. If you are local to socal I could lend a hand.
It’s not a very hard job, the hardest part is loosening the rings that seal/attach the fuel units to the tank. It took me about two hours but now i could do it in 30 mins. I removed both seats, took off the covers under the seats. Unplug connectors and hoses, be careful because the hoses are under pressure and will spray fuel for a split second, have a rag over the hose you disconnect. You remove the hose by pinching a small clip. Take off the two retaining rings. There are two hoses that will connect the fuel units together. I started on the passenger side and tied a wire to the end of it so that i can pull the same wire back with the new assembly and not fish for it in the tank. Do everything in reverse order. I cycled the ignition to prime the pump a few times before starting. If you are local to socal I could lend a hand.
Thanks for the reply. I just ordered the part and seal from FCP. Seems pretty straight forward. Any special trick to get those rings off that you said was the hardest part?
I would take off the seat and cover to make sure that the top of the fuel assembly is cracked, there is a big o ring under the retaining ring but mine was still in good condition. You might also be able to ask mercedes if they could fix it on their dime. I used a flathead and hammer to spin off the retaining ring. My dad was helping me hammer away as well. Looking back i would try use something like a air hammer or hammer drill(no spin) to get it off. good luck!
Thanks for the reply. I just ordered the part and seal from FCP. Seems pretty straight forward. Any special trick to get those rings off that you said was the hardest part?
There is a special tool for this. Search feature on this site, Google and YouTube will help.
$17 on Amazon. Use a ½" drive 18-24" breaker bar to make life easy. Youll have to remove both sides to disconnect two hoses and fish them through. Its easy and took me 30 min start to finish. Make sure your at less than ¼ tank of fuel!
Hi everyone. I searched the forum and Google to no avail. I have smell of fuel from the driver side rear of the car. I checked for leaks on the ground but nothing. It is strong enough you can smell it in the cabin. I check under the rear drivers side in front of the tire as there is a cover there that felt a little damp and had a little gas smell. I am assuming fuel lines are under there. Anyone have this issue before and what was the cause? I didn't see any recalls for this car when it comes to fuel leaks. Thanks for any help.
I have a 2013 cls550 and I have that smell when I start it up. It’s very strong and there is no leak.
this link will send out to a guy who doesn't speak on his videos but instead are intelligently produced. He drives a W212 but it looks nearly identical to what you need to do to access and repair your issue. You probably have the same think I did which was a crack in the sending unit plastic. You can check it out by removing the seat cushion and 4 8mm bolts that remove the access cover. It'll be obvious. I bought mine on FCPEURO.COM but make sure you buy the o-ring seal because my housing didn't come with one.
Make sure your tank is less than half full, preferably ¼ tank to avoid messes. Also, make sure you buy the locking ring tool if your car has one. I bought one on Amazon for $18. I used my locking ring tool and a ½" drive breaker bar that is 24" in length. Made quick work of removing and reinstalling the locking ring.
Dasbecan Fuel Pump Removal Tool 5 or 7 Holes Type Fuel Tank Lid 5.31-inch to 7.17-inch Adjustable Lock Ring Spanner Compatible With Ford Nissan Land Rover Volvo Mercedes-Benz https://a.co/d/14y1dN1
It’s not a very hard job, the hardest part is loosening the rings that seal/attach the fuel units to the tank. It took me about two hours but now i could do it in 30 mins. I removed both seats, took off the covers under the seats. Unplug connectors and hoses, be careful because the hoses are under pressure and will spray fuel for a split second, have a rag over the hose you disconnect. You remove the hose by pinching a small clip. Take off the two retaining rings. There are two hoses that will connect the fuel units together. I started on the passenger side and tied a wire to the end of it so that i can pull the same wire back with the new assembly and not fish for it in the tank. Do everything in reverse order. I cycled the ignition to prime the pump a few times before starting. If you are local to socal I could lend a hand.
Hey BenzFan2001,
Thanks for the helpful replies. Unfortunately I have the same issue. Just purchased the car last year (2012 w/ 50k miles) and I’m in Huntington Beach. Was wondering if your offer to help still stands? I’ve already had to do the airmatic suspension this year, and really would like to avoid taking it back to the shop. I’m handy, but haven’t worked on something like this before
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2012 CLS 550 Fuel Leak Smell ???
