AC System Slow Leak (1 Viewer)

[MTrun]

Hey mudders, I know there are a lot of discussions on AC leaks. Wanted to share a few more here if they are of help to others. My AC air volume decreased until almost no air was blowing on a long drive before July 4th. The air was cool, but VERY low volume. I also had a few drops of water in the passenger footwell. Another member pointed out that the evaporator was likely frozen, a possible symptom of low refrigerant. He was right, shutting the AC off, but putting the fan on high, it thawed in a matter on minutes.

 

[MTrun]

A week later, I had a shop pump down the system and refill, the tech said there was only 0.8 lbs of refrigerant left by his math and he filled it. I also asked him to add UV dye and I would spend the next couple weeks looking for leaks. Cost was $85 for the vacuum, and refill.

Well, today was leak check day after my $20 UV light arrived and I found this...

There appears to be small cracks in the aluminum (from expansion/contraction?) in the first photo, and clearly dye coming out of the AC drain.

 

[jahawk]

I'd be tempted to clean the dye off and give it few days to see if it comes back. Everything I see is in the area where the dye might get just from removing the charging hose from the connector.

Jim

 

[flintknapper]

Hey mudders, I know there are a lot of discussions on AC leaks. Wanted to share a few more here if they are of help to others. My AC air volume decreased until almost no air was blowing on a long drive before July 4th. The air was cool, but VERY low volume. I also had a few drops of water in the passenger footwell. Another member pointed out that the condenser was likely frozen, a possible symptom of low refrigerant. He was right, shutting the AC off, but putting the fan on high, it thawed in a matter on minutes.

I think you mean 'Evaporator'. Dye coming from the drain hose (evaporator box) points to a leak in that area.

The other dye (at the service port) I would clean thoroughly and recheck later. Likely just refrigerant/oil from the service itself.

My 'guess' is that you have a small leak in the bottom of your evaporator. They will corrode (usually in a corner) when/if the evap box collects debris. The evap is then sitting in a mixture of wet dirt/dust/leaves/etc.....The Orings for the TXV might also be leaking (same area).

Continue to investigate.

 

[MTrun]

I think you mean 'Evaporator'. Dye coming from the drain hose (evaporator box) points to...

Good call Flintknapper, changed the original post to evaporator. As you and Jayhawk have suggested, I have cleaned the dye near the service port and will recheck. There appears to be micro-cracks in the aluminum there at that bulp shaped piece, but perhaps just from original manufacture? Investigation continues.

 

[MTrun]

Day 2, looks like you guys are correct, not much more dye in the engine compartment, other than a rather large pool of bright green dye in my driveway dripping out of the AC condensation drain. Time to address the front evaporator. I am taking my lead from the following two existing threads:

Replace A/C Evaporator Core and Expansion Valve

AC Leak?

I also am taking advantage of this time to add a cabin air filter capable cover that was SUBSTANTIALLY cheaper through PartSouq while ordering parts.

 

[MTrun]

Updated to reflect the final parts I used:

1x Denso 476-0046 A/C Evaporator $148.79 Rock Auto
1x Denso 478-1500 A/C Dessicant Element $11.41 Rock Auto
1x Denso 475-2024 A/C Expansion Valve $16.54 Amazon Rock Auto
2x OEM 9009904497 A/C Refrigerant line bolt $0.96 PartSouq

Optional items for cabin filter addition & drain extension:
2x 1x Denso 453-1001 Cabin Air Filter $10.67 Rock Auto (Note: this ended up being a two pack!)
1x OEM 88891-60040 Cooler Cover $14.79 PartSouq
1x OEM 88891-60060 Cooler Cover door $12.79 PartSouq
1x 88578-47040 OEM packing cooler strip sealer, $12 Stealership
1x 100/120-Series AC Drain Extension Kit, $8 Cruiser Garage

Consumables:
PAG refrigerant oil
Replacement A/C O-Ring kit
Replacement Schrader valves
Nylog Blue

Rear Hard Line replacement:
1x 88726-60630 - rear line ‐ Dealer $168.92
1x 88726-60650 - rear line - Dealer $124.83
1x 90119-06003 - corroded aluminim bolt for rear line to rear evaporator - Dealer $2.89

 

[flintknapper]

I will update as I verify I have the correct parts (Or please correct me) but I am ordering the following:

1x Denso 476-0046 A/C Evaporator $148.79 Rock Auto
1x Denso 478-1500 A/C Dessicant Element $11.41 Rock Auto
1x Denso 475-2024 A/C Expansion Valve $26.66 Amazon, Rock Auto is back-ordered
2x OEM 9009904497 A/C Refrigerant line bolt $0.96 PartSouq

Optional items for cabin filter addition:
2x Denso 453-1001 Cabin Air Filter $10.67 Rock Auto
1x OEM 88891-60040 Cooler Cover $14.79 PartSouq
1x OEM 88891-60060 Cooler Cover door $12.79 PartSouq
1x 88578-47040 packing cooler strip sealer (tbd, still sourcing)
...plus whatever wishlist parts the checkbook allows since I am paying shipping anyway.

Also:
PAG refrigerant oil
Replacement A/C O-Ring kit

Looks good.

IF you can source (or order) a small bottle of 'Nylog' (it last you a lifetime) it is cheap insurance of no leaks at Orings, Mating Surfaces and Schrader Valves. I have no affiliation with them....just passing on a 'tip' about a really good product. I won't do A/C work (parts replacement) without it.

Use it to coat Orings and mating surfaces. Put on the threads of Schrader Valves. Nylog is your friend.

 

[Biga27110]

in for later

 

[MTrun]

Flintknapper - thanks for the pointer! Nylog is en route.

Is there anything else you guys can think of I should do while I have the AC system open? Right now I am planning on replacing the front evaporator, expansion valve and dessicant.

 

[MTrun]

Had to vent for a moment - sourcing parts for this job, against my better judgment I ordered the Denso expansion valve through an Amazon vendor as my primary sources were out of stock. Sure enough what showed up today was NOT Denso, not even a knockoff, just another mediocre brand. Rock Auto has stock again, having to pay rush shipping and paying for the part twice. Grrrrr.

 

[MTrun]

Well lots of updates and photos. I recieved all my parts and tore into the system, just finished replacing the front Evaporator, expansion valve, all associated O-rings and updated the cover with the slot for the cabin air filters while I was at it (best $30 I have spent). Overall the process went very well minus the one knockoff Amazon part I had to await replacement for Denso.

What was unfortunate is that while parts were en route I traced all my high pressure lines to the rear of the system and found pinhole leaks in many places on the hard lines that run to the rear where held by the brackets that so many other users have mentioned. I priced out OEM replacement lines and tested disconnecting the high pressure lines since system is evacuated anyway. As others have found the bolt where the lines attach to the rear cooling unit immediately snapped. The aluminum joints are also giving me trouble, so like others, while I have renewed my front system, I am stuck with the decision on whether or not to now cap the rear lines. I believe I could replace them (the brackets are are letting loose) but that rear-most line attachment at the cooling unit with a broken bolt is going to be a problem.

 

[MTrun]

Look at that debris and pool of UV dye

 

[MTrun]

To remove the evaporator, I did cut the lower plastic bar, but rather than bending the metal brace, I just removed it. It took me less than a minute and surprisingly little maneuvering to slide it out. Two bolts and one nut.

 

[MTrun]

The 'packing foam' in the front evaporator was almost gone

 

[MTrun]

Reusing the tape around the new expansion valve was not difficult, just took a couple minutes to carefully remove and them replace on the new one.

 

[MTrun]

New vs Old Evaporator and expansion valve mounting bolts

 

[MTrun]

Biggest hole found on the rear high pressure lines. Inside the bracket in the location everyone else is finding theirs at the 90 degree bend by the passenger wheel well. I also found indications of UV dye suggesting pinhole leaks inside two other brackets.

 

[MTrun]

Bad day - snapped bolt where the rear lines feed into the rear cooling unit.

 

[MTrun]

And ending on a positive note - fresh cabin air filters being added as I buttoned up the front system with that snazzy new cover & door that actually accepts cabin filters!