ibbo14

Hi Experts,

This is the issue I am having.

I noticed this at first when I started my car in the morning, left it to warm up for about five minutes. When driving off the driveway, I noticed a patch of fluid on the driveway. I went to check it out and it was fuel.

I stuck my hand under that area where (rear passenger side) and it was wet.

I drove off to my local indie to get the car up on a lift and investigate. By the time I got there it was dry and no leak. Strange!

The tank was just about half full and it has not done it again. But you can see that something leaked from the stain.

I replaced fuel filter, though I do not think that is the culprit. I would have thought it was coming from above the tank, but it was not full all the way. I ruled out the lines since they look clean and dry. Sender line and return line look fine.

I don't know if anyone have seen this issue before?

I noticed that I will have to drop the subframe just to get to the top of the tank, but it was half full and should not be leaking from the top.

I am concerned as this can be a fire hazard.




Dark stain area is where it was wet. Now its dry!

Plutoe

Take the rear passenger side wheel well out and look at the emissions canister!!

ibbo14

Thanks for the reply Plutoe.

I am assuming that is on the same side as the fuel tank? (I have a right hand steering in Australia)

Had a look, but it is all dry. No evidence of leaks

Is there a way to look above the tank without dropping the whole sub-frame? Would hate to have to go through all that work for nothing.

MarcusF

The fuel tank is a saddlebag design. Meaning, one half of the tank is on one side, and the other half is on the other. When sitting in the car, the left rear is where you should look. Remove the wheel, then remove the inner fender liner. That is where the charcoal canister is located.

If your fuel tank is leaking, then it could have been physically damaged. It seems unlikely to me that it was damaged on the top of the tank unless someone discharged a firearm in the trunk or was careless with a drill. If the tank itself isn't physically damaged, perhaps the charcoal canister is clogged. If so, one of the hoses used to vent the tank may be leaking under pressure.

Here's a post, with a horrific title, that describes one way to fix a clogged canister:

https://mbworld.org/forums/clk-class...ml#post5931639

ibbo14

Hi Marcus!

Thanks for your reply. Great to hear from you again!

I thought the charcoal canister was on the right, did not realise that it was on the left. I will surely check that out.

I was also just looking at some pictures of the fuel tank and have noticed that the seams are about 3/4 way from the bottom of the tank. I know this is rare, but there could be a chance that the seam has split. Just looking at WIS, looks like a long process to remove the tank.

I'll post back soon with my findings.

Thanks,

Regards!

ibbo14

Hi All,

This issue has been resolved. The fuel tank had developed a hairline crack on the front left side just along the mould seam. See the picture below. I think it was just bad luck in my case

Just a few notes. I went off a compatible part of EPC, but they are incorrect. The original part number is 202 47074 01, EPC states that 202 47035 01 is compatible. But they are not. Do not fall into this trap, this cost me time to return the old part and find the correct one. An expensive mistake!

All fixed now and no more leaks!

Thanks all for your help!

burgca

Glad you found the source, a real safety issue that could be tragic. What year is your CLK?

ibbo14

Sorry for the late reply burgca.

It's from 1999. Indeed a serious issue. I was speculating an age issue with the tank cracking, but the replacement one is even older. Hope it does not happen again. But then I could have hit something and did not realize it.