Fivehunnit

I've noticed this leak which appears to be stemming from a top hose of the radiator?






Is it coolant leaking, or a different system? It seems like an oily sort of substance.
I have a receipt with the car from a while ago stating the transmission was replaced (possibly due to the common radiator problem?) it doesn't state why, or whether the radiator was also replaced, a thread I found stated that the radiator brand is on the top under a rubber flap, but I can't seem to find it.
Does that leak look like a terribly worrisome prospect? I'm going to take it for a service A very soon, along with having a few other things done, just wondering if it's an idea to replace parts of the cooling system to avoid any transmission damage?

Patton001

Doesn't appear to be a coolant hose. Probably a trans cooler line. You might also check your power steering fluid level. Some cars also have a PS cooler built into the rad, not sure about the MBZ though.

Fivehunnit

Yes it sort of looks like PS pipes I thought that initially thanks.
I've been doing more reading and found some worrying signs, the radiator I'm 99.9% sure is valeo, from comparison pics, I've definitely lost some coolant since I've had it, one post said to check for a shiny coating on the water in the reservoir when the engine is cold and yes, it does, it's also a sort of browny colour on top, the car is now parked until I find someone that will fit a new BEHR radiator and change the gearbox oil and filter, is there a chance that the gearbox could be ok? I've not noticed any problems regarding shifting etc

Fivehunnit

Also thinking that the replacement gearbox was done because it happened before, then instead of replacing both the gearbox and faulty radiator, they opted to do just the gearbox and sell it on quick?

Rudeney

Generally, a little coolant in the transmission fluid is not a problem. Once the Behr is installed, just repalce the filter and flush the transmission fluid and it should be fine.

Fivehunnit

Thanks, it's booked in to an Indy garage for Wednesday to be looked at, this is my main concern, the coolant, I pulled some out of the reservoir with a turkey baster, notice how it looks normal under normal light



Then, when a torch is put to it








It goes brown, is that a sign of ATF in there, or something else, or is it likely just from generaly needing a coolat flush?

Rudeney

The coolant should look more "orange", I believe you may have some contamination.

Fivehunnit

Update, got the old rad replaced with the newer valeo by PMW Chelmsford.
(RA 1409)