Leak test without dye
 

I visited a A/C repair shop last Saturday, the guy told me they have a special equipment to test leak without adding dye, and he also said they custom made these high pressure A/C hose instead of paying dealer too much of money, how does this sound?

Using an electronic "sniffer" is pretty standard procedure these days. Dye is still used for those slow, slow, slow or intermittant leaks that never are there when it's at the shop. A shop with the right equipment and expertise can swedge/crimp/press a custom hose for you far more inexpensively than buying premade from a dealer. If everything else checks out (recommendations, certifications, BBB, experience with MB's) then you may have a shop at the top of their game.

What model?
 

Depending what model. However, in my car I chased a leak from the evaporator both ways. The "sniffer" did not catch it. The dye, did at the bottom of the car, in the transmission tunnel.
As far as the hose, it is true. Most places where they make high pressure, hydraulic or A/C hoses can make/repair your old one for a fraction of the cost of a new one.
Make sure this people are familiar with Mercedes Benz.:eek:
Good luck!