Ac evaporator?

[mcalvarez73]

Hello Guys,

I need your help!

I've been having A/c leaks for few months now. I finally took to it an A/c mechanic this past friday when he was about to close. He charged the system, placed dye in the system and let me drive over the weekend. He asked to come back today(monday). I came back this morning, he didn't see any leaks under the hood. But he detected freon leaks in the A/c vent. He told it is definitely the evaporator and needs to be changed. I came home and i was able to remove the evaporator. I didn't see signs of freon on the evaporator, but discovered freons where the expansion valve is located. Should i go ahead and replaced the evaporator and expansion valve? what do you guys think?

 

[Supra88]

Yes. You have to pull the evaporator out to get to the expansion valve, so you may as well replace both. Put in new desiccant before you recharge. You'll have to cut the plastic below the glove box to gain enough access to remove the evaporator unless you want to remove the entire IP.

There are some good write ups on this if you do a search.

 

[The Mack]

Actually the expansion valve can be replaced though outside opening where the tubes connect on fire wall.

The system needs to be evac first, and tubes need to be is disconnected firs, and take off the two bolts holding the metal surround on the fire wall.

The tar insolation will need to be taken off first, than take off the two allan screws off the expansion valve to the evap.

After the screws are removed, gently pull the expansion valve out.

 

[mcalvarez73]

after inspecting the evaporator and expansion valve, i think the problems are the expansion valve orings... can i buy just the orings at the dealership? Do i need new drier since the system has been disassembled or opened?

 

[The Mack]

Any auto parts place will carry these orings in various sizes. My orings were shot, got them from Advance auto parts.

 

[mcalvarez73]

To THE MACK, i think i will start with the o rings first, there are total of 4 orings i need to replace and have it charged again.. should i buy a new drier?

 

[The Mack]

Nope, just replace the dryer/filter/absorbent sock/ and plug (PN# 88474-47010) on the dryer.
The new pug comes with new orings. If you end up replacing the absorbent sock I suggest having a very long needle nose type pliers on hand to pull the old one out.

 

[Sharon]

Help, I'm new to this forum (about 5 minutes in actually) and I could use some advice. I'm a hardened
gearhead but have no experience with Toyota/Lexus

I'm helping a friend who has a '96 lx450. I've charged her a/c system several times and it usually last about a month before the freon is low. When it's fully charged it works great, around 40 degrees at the vent. I finally added UV dye during the last charge and after a week can find no trace whatsoever of a leak anywhere under the hood. The schrader valves are the only place that shows any dye but since that's where I injected it that seems only normal. Additionally only the threads of the two valves shows any dye not the inside of the caps.

This leads me to believe the only other culprit must be the evaporator or expansion valve "O" rings. Is there a known issue with this year car having evaporator problems?

I read an excellent step by step post on this forum on the removal of the cooling box so that's where I'm heading next.

Is there any way to check for leaks in that area without removing it?

Thanks so much in advance for sharing your expertise!!!

 

[The Mack]

I personally cannot help out on a 1996, but on my 1998 it was the evaporator that was leaking.
Their was a lot of dirt/dust buildup from lack of cleaning that caused the thing to corrode over time.

First tool you should have is an freon refrigerant sniffer. This will make your job of finding leaks faster and more precise.

Not sure if these had an interior filter setup, but look at evap box to see if it has a slot for air filters.

If it has this one can remove and look inside with a flash light.

 

[Supra88]

I personally cannot help out on a 1996, but on my 1998 it was the evaporator that was leaking.
Their was a lot of dirt/dust buildup from lack of cleaning that caused the thing to corrode over time.

First tool you should have is an freon refrigerant sniffer. This will make your job of finding leaks faster and more precise.

Not sure if these had an interior filter setup, but look at evap box to see if it has a slot for air filters.

If it has this one can remove and look inside with a flash light.

You can pull the fan motor in about 5 minutes and peek up at the evaporator. I recommend shooting some dye in the system to see if you have leaks or just take it to an AC shop and have them diagnose it.