My 2009 ML350, 47K miles, is at a new MB dealer for service A. They tell me transmission pan and rear brake lines have rust and recommend me to make replacement. quote for transmission pan is $720 and brake lines for $6500!! They tell me it's ok not replace now but need to be monitored carefully.

They also told me oil leak from cam magnets, replacement for $800. I will change cam magnets.

I never had so much quote over $2000 at other dealers each year before, I did everything at dealer every year but I wanna know do I really have to change everything at dealer? $6500 for rear brake lines?

 

Unless you are driving in the ocean or on a lot of salted roads in the winter, in my estimation, having rust on the trans. pan and brake lines in 8 years seems a little odd but not impossible.
Have you looked under the vehicle yourself? Rust is easy enough to spot. So with a flashlight you should be able to verify that yourself to confirm their diagnosis.

 

You must live really close to salt water, or be regularly towing your boat in and out of salt water, or live in a part of the country where they use salt on roads, to have that kind of problem. I can relate, though; I'm originally from Puerto Rico and have dealt with salt water corrosion on everything that can rust for years.

If the dealer says it's not bad now it might be worth it to put it on a lift and get a good close look yourself. It's entirely possible that you could remove the surface rust (or pay someone to do that) and then treat the bottom with an underbody sealant to protect it. If a sealant is not your preference, or the rust is worse than you thought (DON'T hide it under the sealant, it will just keep rusting away), then I suggest generous spraying with lots WD-40 (there's a reason the WD stands for "water displacement") in dry conditions, then let it dry overnight. The film left behind will greatly protect from corrosion (and in other places, like the engine compartment). Easy and cheap to renew every few months, too. There's another product that I use, it's called "Corrosion-X" and is used in places like inside airplane wings to keep things corrosion-free. Same concept, works very well. You can buy it at http://www.corrosionx.com.

 

Have you gentlemen noticed that the OP hasn't replied to his own post in 7 days?

 

And?

 

You are wasting your time.

 

I disagree, but even if I were, it's my time to waste.