Stupid trucks and road debris. Sometimes I feel like I am playing that old video game Astroids commuting back and forth to work! Except I don't have blaster canon to blow stuff up before I hit it. The lastest incident involved something being flung up by a truck ahead of me. Traffic was tight so there was no where to dodge without Bristol type Nascar pileup. I was relieved to see that the missle had at least at least landed back on the highway so it would not hit the front of the 300TD. I heard a thunk as I traveled over it but the exhaust note and handling remained the same so thought it had just bounced harmlessly off the bottom of the car.

Coming home that night I noticed that the fuel gauge was staying at the full mark. So I either was getting 60 mpg or something happened to the sender. I didn't connect the 2 events until yesterday when I finally pulled the sender. The end of the sender tube was smashed and the whole tube was kinked slightly. Damn this was a new sender I had installed a few months ago!! I thought it might be a tank vacuum problem but looking under the car I could see an area about the size of a basketball indented right under the sender, definately caused by an impact.

I took the sender apart and the metal shaft had fractured in two of course taking out all the sensor wires. Fortunately I still had the old sender and I had purchased some 3 mil ni-crome wire to repair the old one before finding a new one for cheap on eBay. It took forever to get the ni-chrome wire strung properly but finally got it right with good tension in the wires. I checked it out with the fuel gauge and it looks like it works fine.

The last operation before putting the sensor back was to get back the tank depth so it would clear the sender. I took a 1.5" wooden dowel and pounded a couple of time with a small 5 lb sledge. I crawled underneath to check my progress and damn again a small leak started on one of creases. I think this area is right below where the rod from the send was.

So it was tank draining time and I dropped it out from under the car during the last remaining bits of daylight yesterday. I quick peek inside showed shiny metal so hopefully corrosion did not cause a weak spot. Tonight I am going to pump out the last bits of fuel and fully inspect the tank from the inside. My plan is to finish hammering out the tank using a non-sparking wood or brass rod then look to put an epoxy patch on it. I was thinking if I could get access, I could possibly patch it from the inside then put a secondary patch on the outside. I should have a better idea when I inspect it more tonight.

So I'm back at the wheel of the W108 250SE. Gawd it feels like a rocketship compared to the 300TD and at lunch it drew a couple of onlookers asking about the year etc... So I guess having the 300TD laid up for another few days is not a totally bad thing!!

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Bill Reimels
Now down to one:
1972 300SE 3.5 W109 (Euro delivery)

If it could whack the fuel tank on a TD like that, you're damned lucky that debris didn't penetrate the lower oil pan...

Over the years, I can't tell you how many flats and dings I've collected from crap falling on the road. Around here, the gravel truckers are starting to put these ignorant stickers on their tailgates : "Stay Back 500 Feet - Not Responsible For Damage". I'd like to think that you can't simply absolve yourself of all reponsibility for your load with the placement of a sticker on your tailgate.

I'm tempted to make a sticker that says

"Stay in front 1/2 mile
Not Responsible For My Actions
If Crap Falling Off Your Truck Dings My Benz"

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Never a dull moment at Berry Hill Farm.

My sister hit an ' alligator' lately and it caused $2000 plus in damage...
Good thing your debri did not mess up your SLS back there... that would be worse than fixing your gas tank and sender....

At first I thought it was going to go right through the windshield or grille. Luckly the ground clearance on the W123 is fairly high. If I was driving some lowslung modern machine it would have been big bucks for sure.

Anyone need ni-chrome wire? I have about 25 feet of it. Hopefully I won't need it all!!

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Bill Reimels
Now down to one:
1972 300SE 3.5 W109 (Euro delivery)

I would change the tank as demand is so low for this item may be dime a dozen in your area as in mine. If isolated hole okay to try a patch but if sprung seam would not attempt. Clean area pefectly around hole and solder on a patch is even better if done properly. Then back it up with epoxy or whatever if you are unsure of patch integrity. Cleanliness is the secret. Also feed exhaust fumes from a gas car into tank when soldering it. Or buy a can of tank neutralizer to clean it out before soldering. At least thats what I would do. You may have to remove tank anyways as that dent may not be pushed out enough to take new gauge. Just a few thoughts.

Thanks Barry for the comments. The hole turned out to be crack right where one of the ribs on the bottom of the tanks ends. It was about 10 mm long. I'm surprised that the metal could not take the deformation without cracking since there is no sign of corrosion anywhere on the tank. Maybe the velocity of the impact had an effect.

The dent was centered around the screen filter. I was able to get the end of a small C clamp inside the screen filter hole. I suspended the other end from my come-along hooked to a beam. By beating around the opening with a hammer and block of wood I was able to get the dent pulled out fairly well. It least the pickup is now at least level with the area under the fuel sender.

I washed out the tank a number of times with a strong degreaser and dryed it out with an air hose. I sanded and cleaned around the crack and took a pick to open up the edges of the crack and make sure they were totally clean. I taped the hose from my shop vac to the fuel filler and let it run for about a half hour. With vac still running I silver soldered the crack using a good acid flux. The solder flowed very easily and I was please to see it nicely filled the crack with no voids. I added a little extra solder just to build up and reinforce the area.

Tonight I'm going to replace all the vent and overflow lines before bolting the tank back in this weekend. Not a moment to soon as breathing all these diesel fumes is starting to get to me!!

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Bill Reimels
Now down to one:
1972 300SE 3.5 W109 (Euro delivery)