2010 LX570 HVAC Leak - Diagnostic Help Requested

[LXinOBX]

Hey all! Searched, but no luck finding a similar enough thread to add on to...

Issue: 2010 LX has a slow freon leak, done an evac and refill (w dye) - shop cannot find a leak. They did the refil this past Monday.

I chose this shop because they did amazing work on an issue with this trucks predecessor, a '98 Lx470, mitigating a rear AC line leak. But, I think these guys (they've grown dramatically) just aren't the "same" as they were 10 years ago.

I know there is a leak as I added a full r124 load (filled to lo 40's) last fall, and for a recent drive (as air was no longer blowing cold) a can (12oz) of freon. It was enough to allow compressor to kick in and cool the 4WD enough for a multi hour drive (mid Atlantic heat) w two pups. When I tried the HVAC several days ago, no cold air (I did not but a guage on it).

Can anyone advise what I should do next? The shop has suggested I pick up the truck and drive it a few days then we can check for dye? For a super slow leak, does this sound like a reasonable time (a week) for the dye to present itself? Secondly, just how difficult is it to "see" (borescope) the condenser/evap unit (without taking dash apart) to check for dye? I have not asked if they did that?

Anything else and other advice?

Thanks so much!!!

Bll

 

[GrouchyTech]

Charge it completely, then use a UV light and a refrigerant sniffer.

 

[LXinOBX]

Charge it completely, then use a UV light and a refrigerant sniffer.

Appreciate the note back! Sorry, wasn't clear, did a complete extraction/refill ($320) after the shop did a "full" stem to stern check w the UV light, to no avail. I think the leak is just so small that no "tell" dye marks yet. No discussion of a refrigerant sniffer? They agreed to a review to look for dye marking AGAIN...should a week be enough time?

Many thanks, really appreciate any/all advice!

 

[GrouchyTech]

Appreciate the note back! Sorry, wasn't clear, did a complete extraction/refill ($320) after the shop did a "full" stem to stern check w the UV light, to no avail. I think the leak is just so small that no "tell" dye marks yet. No discussion of a refrigerant sniffer? They agreed to a review to look for dye marking AGAIN...should a week be enough time?

Many thanks, really appreciate any/all advice!

If the evaporator is leaking sometimes there won’t be a noticable amount of dye in the evaporator drains, but a refrigerant detector might smell it in the vents.

 

[LXinOBX]

Did not know that (thought a bore scope review would be sufficient), thank you, I'll check w the shop. Any other thoughts/ideas are welcome!

 

[LXinOBX]

OK...update, hoping some of you smarter folk might have an idea. Fast forward to a week ago. AC is no longer blowing cold so recharged (only one 12oz can) of refrigerant so as to run AC in truck for dogs. AC held (still holding) for about a 6 hour drive. Went to autozone to (again) rent the leak tester.

After going stem to stern (engine compartment to rear ac - and lines (drivers side). Nothing of significance...except this (see attached pic). The pic didn't jump out as much as the eyewear/black light did insitu.

Could I have a pin hole leak (rock?) this is on drivers side, just ahead of rear tire - if so, what is best way to test? Maybe, clean area and see if some of the dye (still in system?) reappears?

 

[CanadianRockyCruiser]

Looks like a pinhole leak to me. You can recharge and test with soapy water, if you want, but you're probably wasting refrigerant. There are kits you can buy to repair a/c pressure lines, and they work decently. This sort of thing:

You can, of course, replace the entire line with a new one too.

Either way, remember to vacuum the system and check that it holds vacuum, before refilling with a new charge.

 

[GrouchyTech]

Either way, remember to vacuum the system and check that it holds vacuum, before refilling with a new charge.

I want to add that pulling a vacuum to test for leaks is just one reason (and won’t reveal certain leaks). Another reason is to evacuate the moisture that enters while the system is open.

Ideal conditions would be least an hour or more at a vacuum of 500 microns or less.

 

[bloc]

The real question is why you have an AC line there? That's nowhere near where they originally run on our vehicles.

 

[04UZJ100]

The real question is why you have an AC line there? That's nowhere near where they originally run on our vehicles.

This. Isn’t that the parking brake cable?

 

[bloc]

This. Isn’t that the parking brake cable?

I believe it is.

 

[GrouchyTech]

I believe it is.

It definitely is…

Rear evaporator may be dripping onto it.

 

[LXinOBX]

Gents (especially grouch, bloc and 4uz) , thank you (and, boy, am I embarrassed as it prob is the hand brake channel)...I never even considered what lines I was scanning w the UV light...just looking for the "tell". This is driving me absolutely nutz as despite crawling around underneath, in the dark, for almost an hour I simply cannot see any other "iridescent" spots. I don't have access to a "sniffer" but the AC vents didn't "show" iridescence inside.

Just to confirm, all the AC lines (this is an LX), once exiting the engine compartment, run down the drivers side of the truck and the rear "system" resides above the driver side rear wheel, correct?

 

[LXinOBX]

Looks like a pinhole leak to me. You can recharge and test with soapy water, if you want, but you're probably wasting refrigerant. There are kits you can buy to repair a/c pressure lines, and they work decently. This sort of thing:

View attachment 4213835

You can, of course, replace the entire line with a new one too.

Either way, remember to vacuum the system and check that it holds vacuum, before refilling with a new charge.

Just wanted to chime in on this post...referencing an LX 100, but a local shop mitigated a rear feeder AC leak using one of these. The write up is in here somewhere...net/net w this approach I did not have to remove the body from frame and the total fix was thousands less than dealer running a new line

 

[bloc]

Give the area above the exhaust resonator a very good look. The AC lines go through the floor of the vehicle into the rear AC unit. On those lines there are some aluminum block looking things that are where the lines separate to go through the floor. Very common place for refrigerant leaks on these vehicles as they develop corrosion.

To answer your question.. the refrigerant lines on our vehicles don't attach to the frame rail. They run to the firewall then dip down into the transmission tunnel and mostly stay there for the coolbox and back to the rear AC.

 

[LXinOBX]

Give the area above the exhaust resonator a very good look. The AC lines go through the floor of the vehicle into the rear AC unit. On those lines there are some aluminum block looking things that are where the lines separate to go through the floor. Very common place for refrigerant leaks on these vehicles as they develop corrosion.

To answer your question.. the refrigerant lines on our vehicles don't attach to the frame rail. They run to the firewall then dip down into the transmission tunnel and mostly stay there for the coolbox and back to the rear AC.

VERY much appreciated...I'll have another look tonight.