Ac leak help needed...

[Notsure]

I have a 2004 epxy with possible ac leak. Here's what I did too try a diagnose.


1. I pressure tested ac system, I believe the expo was off.
Gauge reading ( low side 97 psi and hi side 101 psi ).
2. When I disconnected or attached gauges it seem like the last of freon may have escaped. The pressure was very weak.
3. I added a total of 42 oz of freon and uv dye.
4. Hooked gauges up and of course again freon and dye sprayed everywhere. It must be due to unsteady hands. Can not remember if truck was running or not. After freon add the reading were. Since I spayed the ink everywhere I figured I'll let dirt and dust cover the ink and look for fresh ink leaks.
Gauge reading ( hi side 85 psi and hi Side 150 psi )
5. Now it's time to change the rear blend door and temperature actuators. After removing the rear panels I found what may be my leak. Is this the dye or something else?
Pic
Any insight on this is appreciated.

 

[Hamfisted]

Wow so much purple, you're really digging into to this. Do you have access to a Freon sniffer ? But from the photo I'd say the leak is in the rear evaporator or possibly the expansion valve. The greenish aluminum block looking thing is the expansion valve. You can put a little dishwashing soap around those pipe threads to check for a leak. It's possible that it's just a pipe fitting or O-ring connection.
At least you found the leak culprit. If it ends up being the evaporator you might want to check around with local automotive A/C repair shops and see what they charge to install a new rear evaporator since you've already done the discovery work. Since I see a ton of purple ontop of the drain tube, right under the expansion valve, you might be "lucky" that it's only the expansion valve. Either way, it's probably time to recruit the services of a good A/C tech.



-Mike



Motorcraft YG-381 rear expansion valve ....

CPS Freon Sniffer....

 

[Notsure]

That purple is a uv light I'm shinning on the valve area while taking the photo. I have a few pics, don't know how to post them in one post.

 

[Notsure]

Another pic

 

[Notsure]

One more pic... Thanks for input.

 

[Hamfisted]

Well those pics make it look like the expansion valve is the culprit. Do you have all the tools and vacuum pump to vacate the system, change the valve and O-rings, and re-charge the system? This is where a Freon sniffer really comes in handy. You can find a CPS sniffer online for about $200, a vacuum pump at Harbor Freight or online for $100-$200, and the expansion valve at Rock Auto for about $32 (YG-381). Make sure if you do the installation that you only use new A/C certified O-rings on the pipe fittings. Don't use common automotive O-rings, as they won't hold up.
Or just take it to an automotive A/C shop and tell them to replace the rear expansion valve and recharge the system.




-Mike

 

[Notsure]

Thanks for the reply. I'll try to find a freon sniffer for rent to verify that is the leak. Etheir way ill have a shop evac and replace the parts. I would just like to be sure I know where the leak is.

 

[Hamfisted]

Well most likely any AC shop that can do the system evac/recharge will have a Freon sniffer to double check the leak before signing it off. You've done all the hard work.


-Mike

 

[buildingdoc]

You can also use nitrogen to charge the system to 100-150 psi and some soap bubbles. I would also shine your light into the end of the drain tube to see it there is any dye residue. The would also include your evap as well as a TXV. Seen too many guys do a job twice under an assumption. I never had to do a rear evap on an expy so not sure if the job is that bad. some jobs you just do things "while your there" Your new TXV should also come with orings as well.