Toyota Repair: Toyota Sienna 2000 freon leakage, c lines, uv dye

Question
I have to fill up A/C system with new freon every 4-5 mths. Mechanics can't find the leak, even with the UV dye. Which part of A/C could be the the most likey suspect ?


A common leak if it has rear a/c is the connection at the freon line that connects the front pressure lines to the rear a/c evaporator, these lines can be inspected from underneath, the leak is normally visible at the connectors near the front, I can't say that this is the case but I'm just saying that they have a tendency to leak there and the remedy is to replace the o-rings on the leaking freon line, I have done this many times and if you like I can send an illustration locating these freon lines that have the problem, please provide an email address if you need the illustration.

HELLO TED! IN 2007 YOU ANSWERED SOMEONE ON THIS PROBLEM. I HAVE EXACTLY THE SAME NOW. CAN I FIX THE PROBLEM MYSELF. PLEASE HELP ME!
MY EMAIL ADDRESS IS  

Answer
Look underneath the van you will see two a/c lines going back to the rear a/c near the exhaust pipe, both lines have a union there with o-ring seals in them, replace these o-rings it's the most common source of the leak on this model. If there has been a leak for a while there should be an oily black buildup around the area.