An investigation of AC Issues (1 Viewer)

[ClassyJalopy]

Last week when we had our first 80 degrees day I started noticing that AC wasn't able to keep up. I had the two AC lines going to the rear AC replaced and system charged a couple of years ago. At that time the shop also put some green dye in it.
So I started looking for any obvious leaks. Right away this link at the condensor was pretty obvious:

So today I dropped it off at local shop to evacuate the system and check for leaks. They are claiming that following components need to be replaced to fix the issue:
1) Leaky Compressor (see pic below)
2) Rear AC (both refrigerant and suction) lines where they go into rear expansion valve
3) Front Expansion valve
4) Receiver/dryer

Here are the pics they shared:

 

[ClassyJalopy]

@highkick05 This is my thread on AC repair. Thanks for your suggestions so far

Here are part numbers for everything:
Rear AC Refrigerant Line : 88726-60650 $72
Rear AC suction line: 88717-6A220 $260
CLAMP, PIPING: 88718-6A220 $10
CLAMP, piping: 887186A230 $10
CLAMP,PIPING: 88718-6A330 $7
INSULATOR, PIPING: 88714-95D00 $1.15 x4
BOLT: 90119-06003 $1.19
COMPRESSOR ASSY, COOLER: 88320-60681 $374
VALVE, COOLER EXPANSION 88515-48040 $67
EVAPORATOR SUB-ASSY, COOLER, NO.1: 88501-60190 $305
TOTAL About: $1123

I can get everything besides the rear lines from Rock auto (GPD and TYC brands) for about $375
I am leaning towards buying the Rockauto parts and install myself.

 

[ClassyJalopy]

I just need to be 100% sure that compressor actually needs to be replaced. It is kicking on just fine right now and I am not sure what other lines will break once I start moving stuff around.
@bucfl thread here is very encouraging:

Replace AC Evaporator - Expansion Valve - Receiver Drier

First a big thanks to @Ohiolc100 and @flintknapper for their valuable knowledge. I will start off that this is my first time doing this and i took pics along the way so that others can benefit. As im not an expert in auto refrigeration this will not have in depth instructions but more of an...

forum.ih8mud.com

 

[highkick05]

Based on my experience just fix these:
1) Leaky Compressor (see pic below)
2) Rear AC (both refrigerant and suction) lines where they go into rear expansion valve
3) Front Expansion valve
4) Receiver/dryer

The AC systems in cars are built to last. Actually built to last longer than home appliance/ refridgerators .

These days cars made for 10 years , fridge 5 years (I've had to get a mechanic for both in the last 6 months so the appliance technician said about fridges).

Everything else if the shop has said is fine, you could probably bank on being 100% ok. That compressor does look a couple shades greenish.

Maybe someone can buzz in and tell you in which order you can go , to have the system atleast 3/4 cold, without damaging a new AC Compressor.

Your Receiver/dryer will be cactus if the shop says so, the Compressor and Dryer are usually done together because the dryer makes sure clean refridgerant is going to the AC Compressor & not causing damage. I would knock these over first @ the dealer But the compressor is quite costly.

Evapourator will be fine, so that is money saved

 

[BadReligion]

If the compressor is leaking, its likely at the suction and pressure connections. I don't think the compressor needs to be replaced yet. The line going into the condenser seems to leak a lot, likely due to tugging during TB/WP replacement. As others have mentioned, definitely need a new dryer for the condenser when you open that up. Those are only a few $$. For the rear, again I think the lines are ok and its just the connection going into the expansion valve that is leaking.

Why did the shop recommend replacing the front expansion valve? Visible dye at the bottom of the front evaporator? This one is kind of a pain to change so if you have to do it, I would highly recommend "cutting" the plastic piece at the bottom of the glove box instead of pulling the dash. 10min vs 3-4 hours.

Make sure you get a new o ring kit for all of the connections and use Nylog Blue on everything. Charging the system is not complicated with a good vacuum pump and set of gauges. I'd say do it yourself.

 

[highkick05]

@BadReligion has given you a good option.

You could get away with a slightly leaky compressor, its a major expense a new Denso A/C compressor.

Fix the o rings and dryer, make sure you vacuum old (dirty) gas well and then pump some new AC refridgerant into the system and check if holds pressure.

If ok then good to go. AC should be cold, for how long is worth checking later. Bonus is you've repaired most of it already

 

[JunkCrzr89]

Following. We hit 120 in Phoenix recently and my A/C was blowing hot. Only had 22 psi, so have a leak somewhere I recharged but know that major replacements are needed soon...

 

[ClassyJalopy]

If the compressor is leaking, its likely at the suction and pressure connections. I don't think the compressor needs to be replaced yet. The line going into the condenser seems to leak a lot, likely due to tugging during TB/WP replacement. As others have mentioned, definitely need a new dryer for the condenser when you open that up. Those are only a few $$. For the rear, again I think the lines are ok and its just the connection going into the expansion valve that is leaking.

Why did the shop recommend replacing the front expansion valve? Visible dye at the bottom of the front evaporator? This one is kind of a pain to change so if you have to do it, I would highly recommend "cutting" the plastic piece at the bottom of the glove box instead of pulling the dash. 10min vs 3-4 hours.

Make sure you get a new o ring kit for all of the connections and use Nylog Blue on everything. Charging the system is not complicated with a good vacuum pump and set of gauges. I'd say do it yourself.

Solid advice! I think I will just refresh the connections with fresh orings and nylog blue and try to recharge it first. The compressor was always whisper quiet and never made any vibrations so I am not convinced that it is croaked.

I will trace the rear lines visually to make sure there aren't other leaky spots on them.

Finally, the shop did find some dye at the expansion valve, at the firewall. They don't think the evaporator is necessarily bad but are recommending replacing it as precaution.

Finally, I understand that evap isn't the simplest of jobs but oddly enough I am really interested in replacing it because there is a rather large air leak at the seals between air box (blower housing) and the evap box. The air leaks lets in frigid winter air in in winters. I want to take it all off from the firewall and seal all the leaks up for good.

 

[ClassyJalopy]

Here's a super dumb idea: How about I just replace the dryer/desiccant and recharge the system as it is? THe most obvious leak at the condensor is already taken care of. If it holds pressure then it shouldn't cause any additional issues, right? At worst it won't last long but is it worth a try?

 

[ClassyJalopy]

Ok - I got antsy and decided to pull vacuum on the system to see if it is even holding any. It is at -25 inHg for about half hour solid. Is that enough?
I know, I know I still need to replace the dryer element!

 

[ClassyJalopy]

Live updates continue: I failed like to remove the lower plug for the dryer chamber. It is not coming off with medium level effort and I am not comfortable going all hulk on it. I have broken way too many bolts like that! So the dryer stays. I am now running the vacuum pump on the system for 2 hours straight to try and get as much moisture out as I can.

 

[nissanh]

When it comes to AC, just replace the broken parts especially if you are a DIYer, you can repeat the process without labor and FUN!. I have dealth with AC systems and more you disconnect more leaks down the road. Keep all factory joints as is and fix it only if its leaking.

Make sure to clean the condenser and raditor fins to make the system to run cool. Check the condenser fan and fan clutch and keep those functioning proiperly. Just like the transmission, too hot, could cause many issues.

 

[ClassyJalopy]

Just finished recharging the system after running vacuum for 2 hours. The clutch is engaging and disengaging correctly.
At the front vents I am getting 41.5⁰

 

[ClassyJalopy]

So I am not sure how long this will hold but at least at the moment my AC is actually seems to be behaving.
This post from @AFei is the best detailed account I found for recharging the AC system : Fixed: 2004 LX470: AC compressor not engaging with self diagnostic code 21 & 23

 

[BadReligion]

Just finished recharging the system after running vacuum for 2 hours. The clutch is engaging and disengaging correctly.
At the front vents I am getting 41.5⁰
View attachment 2328718

Nice! What was the ambient air temp with that reading? Keep an eye on things, especially the hard lines going into the front and rear evaporators where leaks were suspected or indicated with dye. I'd periodically check your high/low pressures to make sure you are not slowly leaking refrigerant. Your system is already filled, but I ran vacuum overnight, then shut off the pump and monitored the gauges for 24 hours to make sure I didn't have a slow leak.

The potential issue with a slow leak is that you also slowly starve the compressor of lubrication, and then it can seize...which in turn contaminates every single component of your AC system. That's why I had to replace mine in the first place.

Technically refrigerant is not supposed to be a consumable, but if you have to charge your system once every other year due to a micro leak, that is probably managable.

 

[highkick05]

@ClassyJalopy think this vid would be helpful for you reading AC pressures. Glad to see its holding pressure.


Dryer repair

 

[AFei]

This post from @AFei is the best detailed account I found for recharging the AC system

Thanks! So glad I can also make contribution to help other people, in the way I got the help from all over the forum.

 

[AFei]

.....

 

[AFei]

Following. We hit 120 in Phoenix recently and my A/C was blowing hot. Only had 22 psi, so have a leak somewhere I recharged but know that major replacements are needed soon...

I was in the same situation as you, and thought it could cost me 20% of the value of the car to fix the AC. Turn out only costed me $0.63 to fix the leaking, and $20 of refrigerant to charge it back to factory spec. It survived the same 120 degree of heat in Phoenix so far...

Good luck to get your AC back working...

 

[ClassyJalopy]

Nice! What was the ambient air temp with that reading? Keep an eye on things, especially the hard lines going into the front and rear evaporators where leaks were suspected or indicated with dye. I'd periodically check your high/low pressures to make sure you are not slowly leaking refrigerant. Your system is already filled, but I ran vacuum overnight, then shut off the pump and monitored the gauges for 24 hours to make sure I didn't have a slow leak.

The potential issue with a slow leak is that you also slowly starve the compressor of lubrication, and then it can seize...which in turn contaminates every single component of your AC system. That's why I had to replace mine in the first place.

Technically refrigerant is not supposed to be a consumable, but if you have to charge your system once every other year due to a micro leak, that is probably managable.

Ambient temp was 85 degrees yesterday. I might just replace the expansion valve and front evaporator later this summer so I don't have to worry about it long term. We'll see.
Thanks for all the help!