Automotive AC work - txv and evap

[Angel]

Hello All,
for as many Honda Odysseys are out there, their forum support isnt helping me, so I thought I'd ask here. Some of the wisdom will cross over in MB-land Im sure.

The Harbor Freight sniffer tells me that the front Evaporator is leaking on my 2009 Honda Odyssey. I cant find any dye or oil traces anywhere outside the dashboard so I am inclined to believe it (it beeps faster in the inside airsteam and in the drain underneath the van...). caveat - it is from Harbor Freight
It looks like this *might* be a job you can do without removing the whole dashboard, but I havent found good youtubes/pdfs on how to do this - Im still looking...

Question is this: If I do this myself, should I replace the TXV (Thermal Expansion valve) at the same time ? (it is only $20 from the dealer....)
It looks like Im in for the evap coil, a small bottle of PAG oil and o-rings, but I was curious if the TXV's wear out or get old...ever.
thoughts ?

-John

[Zulfiqar]

refrigerant is heavier than air and will be evident at the evaporator drain port as its the lowest point of the evaporator coil box.

the TXV can remain working for a very long time, but whenever a system is opened, I prefer to replace the TXV and the filter drier at the same time - with high quality items.

You will need to check the honda manual for the oil charge when changing the evaporator coil - as the evaporator is a place where the refrigerant boils over, a lot of oil remains in it.

[Angel]

I appreciate the reponse - Im at? a quandry
in a quandry ?

-I have an appointment at the dealer for next tuesday - for them to troubleshoot/diagnose.

-Im new at the whole "halogen sniffer" game - it smelled refigerant(?) in the air vents, and at the drain last night, but tonight I cant get it to read consistently.

-The systems was leaking about a bottle every week or 10 days - thats slow, but enough to want to break things open (or make an appt at the dealer)

-a friend took some pics of the factory manual - you just remove the glove box and then a bunch of screws and everything (up to and including the evaporator) comes out in the passenger footwell
(why cant the german makes do this ?)

-I started removing stuff tonight, because boredom, and now Im looking at the evaporator
The sniffer reads nothing. No dye or colors present. the system is still closed and pressurized.

Do I break it open, get new parts on order, and start replacing stuff ? or wait a day, see if the sniffer reads stuff near the evap again ?
Or just button it back up and send it to the dealer on tuesday ?
I hate to drop $350 on parts if Im barking up the wrong tree.

-John

[Zulfiqar]

I have had good success with the flourescent dye to check for leaks, a leaky evap will show dye in the condensate drain puddle.

changing the evap is not too bad on an Odyssey.