Diesel leak above differential (87 SDL)
 

Thought it might be one of the axle boots - don't think it is.

There's a hose above the diff that seems to be the problem - is it easy to replace? What do I ask for at MB?

Also, when you fill an SDL differential after draining it, how much fluid goes in?

Thanks.

I would think that the only fluids likely to be above the differential would be either brake fluid (from a leaking hose,fitting or tubing) or diesel fuel from a leaking fuel tank or fuel line. The differential oil has no external hoses/tubing.

fuel hose from bottom of tank
 

I replaced mine myself - i recall explaining the part to the guy at the mb parts counter and it comes in one piece with a threaded end to go into the bottom of the fuel tank - just make sure u measure the hose as the new one was too long and needed trimming. Oh and when you replace it you will get soaked in diesel fuel but other than that it's a fairly painless/easy job. good luck!

I should learn to actually READ the entire message. Sounds like you have determined the fluid to be diesel fuel. Hopefully, it's just a bad piece of fuel line that needs either replacement or tightening of a hose clamp.

Re: the differential, I'm not sure how much the diff. on your car holds; but, it should be listed in the owner's manual. If you change it, BE SURE that you loosen the FILL plug FIRST, before draining the fluid. It's really hard to get the fluid back in if the fill plug is stuck. If your car is similar to mine, the plug is a 14 mm hex (which came with the original tool kit on my '72 220d). The volume is probably something on the order of 1.5 to 2 liters.

CRote,

I don't know about the SDL differential, but my other cars have a little breather tube on top of the differential. I am not clear on the function of this thing, but they can become non-functional and cause weeping of the differential fluid from above, leading to oil and mud caking on the differential. I had this replaced on the 1975 240D and it worked, no more differential fluid oozing onto the driveway, at least not from the breather tube. If it is Diesel, chances are it is keeping your differential housing relatively clean. It should also smell much different than differential fluid. Good luck, Jim

Hose doctor
 

Thank you all - sounds like no biggie. And I promise I won't prophylactically run the car out of diesel just to make the job less messy(!).

I hope that the leaking diesel hasn't been eating up my rubber axle booties...don't want my booty busted.