Hello, I have what I think may be a leaking return line for the SLS fluid on the 1985 Mercedes 300td wagon.

The fluid I am using for the SLS is red and is similar in color to transmission fluid and so I have been trying to search and diagnose a transmission cooler hard-line leak in that area. I have been checking my trans. fluid levels for the past few days and it is the same so I have eliminated the leak coming from the transmission lines.

There is no visible leak anywhere near the tank under hood or the pump. The high pressure hose and hard-lines appear dry on the pass. side of the car. The tank is on the drivers side on the 85'. Funny thing is that the level in the SLS tank looks to be the same. Power steering looks good. The car has new hydraulic ram shocks in the back and a rebuilt valve. All good back there.

Always has a small puddle under the car in the morning about 8' diameter directly below the frame cross-member under the engine, where I put the floor jack to jack up the front. It is wet and has red drips coming from it. It soaks into the stone bricks, so I shouldn't say a puddle, but it leaves its mark in the same spot. The suspension works great but the car sinks a bit overnight and I feel it lifting a bit after start up.

I believe the return line is the culprit?

Please tell me they didn't route the return line under the engine between this frame cross-member!!! Why would this be leaking? I can't see in between there very good if at all to tell where this line goes after it comes out of the tank and snakes down to the cross-member abyss. There seems to be very little room between that cross-member and the upper oil pan.

Is it possible the engine is resting on this return line and is causing this leak? Why would they route it in such an inconvenient spot?
Am I having motor mount issues if this is occurring? How much clearance is supposed to be in there?

Thanks.