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Larry W

1994 Lexus Ls 400 A/c Evaporator

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I just picked up my 1994 LS 400 from the mechanic and was enjoying ice cold A/C after installing a rebuilt compressor. clutch, & filter. It lasted for about (2) days and then started slowly getting warmer. The mechanic checked it out today and said the evaporator is blown. I am somewhat familiar with a/c systems, but on American cars (mostly GM vehicles). Is this a huge job to replace this unit? What would be a ball park figure to replace it?

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Hey, I had a similar situation many moons ago and I ended up converting my car to 134a. Cheaper, easy to fill...some say not as cold as r12 but works for me. My leak turned out to be an o ring near the drier (located behind passengers headlight assy). The evap could be a bigger job as I understand because its buried deep inside the dash. Are you + mech sure the leak is there and not somewhere else?

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Hey, I had a similar situation many moons ago and I ended up converting my car to 134a. Cheaper, easy to fill...some say not as cold as r12 but works for me. My leak turned out to be an o ring near the drier (located behind passengers headlight assy). The evap could be a bigger job as I understand because its buried deep inside the dash. Are you + mech sure the leak is there and not somewhere else?

I did convert to 134a years ago. I am going to get a 2nd opinion since its such a huge job. Has anyone done this job? How many hours would you estimate including pump down and recharge?

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Evaporators, like gas tanks last almost a human lifetime. Take car to another shop and have them find the leak using an electronic leak detector tool. There is likely a leaking O-ring seal somewhere under the hood as the other poster said. If you are very unlucky the leak could be from an O-ring fitting under the dash, requiring partial dash disassembly to access.

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Evaporators, like gas tanks last almost a human lifetime. Take car to another shop and have them find the leak using an electronic leak detector tool. There is likely a leaking O-ring seal somewhere under the hood as the other poster said. If you are very unlucky the leak could be from an O-ring fitting under the dash, requiring partial dash disassembly to access.

I took the car to another shop and it was confirmed that the evaporator was leaking. The freon was leaking into the drain tube and we could smell it in the car. Replacing the evap and the expansion valve along with the new compressor, clutch, & dryer from last week and I should be good for another 15 years. Gotta have A/C in sunny Fort Lauderdale. Luckily I found a great mechanic and he can do the job for under $600. Most of the Japanese "only" shops in town want $900. Parts are under $300. Very labor intensive.

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My A/C is out and I took it to a Lexus Mechanic who now works at a Toyota dealership and he determined that since my compressor was bad, to replace it without doing the evaporator was a big mistake and what would most likely happen was what happened to you. Even giving me a break on price he said it would be around $2500 since it involved extensive removal of the dash which was very time consuming. I didn't fix it and just drive my truck when it is hot outside. These LS cars are very hot without A/C so I guess that it it for summer driving in this car.

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I've been down this road guy's... If the parts are under $300 he's going all aftermarket. The cheapest OEM evap core is $450 or so. Evap core leaks are VERY common on LS400's. That and the compressor shaft seal would be the first place I looked if someone came to me with an A/C leak. The evap core on the LS isn't that hard to get to. Some on here will tell you you have to remove the entire dash to get to it and it take $700 in labor. I had a local shop quote me over $2,100 to replace the evap core and compressor with new parts after I had them diagnose it. I took their diagnosis and fixed it myself. Bought salvaged parts off of a wrecked low miles LS and they've been perfect ever since. I fixed my A/C for $200 except for the recharge I had a shop do since I don't have gauges. I had the evap core out in about 45-50 mins, havn't seen anyone else do it that fast. The factory manuals will help because they'll show you where all of the hidden nuts and bolts are. It's been a while but if i remember correctly you remove the glovebox, upper compartment, cd changer, cruise control ECU, ECM (more room with that out), blower unit, then the evap case cover, then the lines into the evap core and it slides right out.

BTW I havn't heard of guy's having much luck with aftermarket evap cores. They never fit right. Hope your mechanic has done one on an LS before. When you pull your evap out of the case it'll either be covered in oil and grime and/or will light up bright green under black light if dye was installed before.

Good luck!

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I will agree, it's not a labor intensive job. I swapped my entire interior a few years ago for gray since the tan looks like puke, the dash is easy to pull but is NOT required when doing the evaporator, you just pull the glovebox, lower dash, ECU, and a few other things, it then slides right out. Most Japanese cars are built this way, all of the Nissans and Toyotas I've worked on in the past are similar in that a few trim pieces are all that's needed to take it out. You can easily do it yourself and save the labor, just have the A/C shop vacuum the system first, then let them recharge it.

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I've been down this road guy's... If the parts are under $300 he's going all aftermarket. The cheapest OEM evap core is $450 or so. Evap core leaks are VERY common on LS400's. That and the compressor shaft seal would be the first place I looked if someone came to me with an A/C leak. The evap core on the LS isn't that hard to get to. Some on here will tell you you have to remove the entire dash to get to it and it take $700 in labor. I had a local shop quote me over $2,100 to replace the evap core and compressor with new parts after I had them diagnose it. I took their diagnosis and fixed it myself. Bought salvaged parts off of a wrecked low miles LS and they've been perfect ever since. I fixed my A/C for $200 except for the recharge I had a shop do since I don't have gauges. I had the evap core out in about 45-50 mins, havn't seen anyone else do it that fast. The factory manuals will help because they'll show you where all of the hidden nuts and bolts are. It's been a while but if i remember correctly you remove the glovebox, upper compartment, cd changer, cruise control ECU, ECM (more room with that out), blower unit, then the evap case cover, then the lines into the evap core and it slides right out.

BTW I havn't heard of guy's having much luck with aftermarket evap cores. They never fit right. Hope your mechanic has done one on an LS before. When you pull your evap out of the case it'll either be covered in oil and grime and/or will light up bright green under black light if dye was installed before.

Good luck!

The mechanic installed the dye after the compressor was done (guess he was worried about the evap). Lexus wanted $1400-$1500 just for the compressor installed. The car just turned 100K so I plan on having it for quite some time. Not sure of the brand name of the evaporator but the price is right. Some times you just have to take a chance. I know a lot of the readers here would die before using a non Lexus part, but I can't see spending another $1000.00 dollars. I'll probably hear from some "diehards" telling me I'm getting what I'm paying for. I'll update you guys after the installation & get the part name. I'll also check on the degree of difficulty from the installer. Thanks for the input.

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Good luck to you and let us know how the aftermarket core works out. It's got to be EXACTLY the same in every dimension for it to slide into the evap case correctly and for the case cover to bolts back up with the ports exiting the cover in the right place. Make sure to ask the mechanic how it fit compared to factory for us.

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Only on very rare occasions do you see any Lexus in junkyards around here. I usually go down there once a month or so just to look around. Finding one with low miles is so rare that most have twice the miles mine does. I didn't realize that the evaporator was accessible without a major tear out. Maybe if I ever have time...

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If you're replacing the evaporator, consider replacing the rec/dryer as well. They often fail within a short period of each other. The re/dryer works like a filter removing moisture and contaminants. I'd make sure the system is thoroughly evacuated before recharging to get out all that moisture and any other possible crap that might be in there like Stop Leak (if it's been repaired before)! Also make sure that when the tech discharges the system that he runs the refrigerant through a recycling machine that cleans it before recharging and topping off with new refrigerant. Though it's desirable to save on costs where possible, one aspect to a cheap compressor is the possibility of weak seals that fail prematurely compared with oem. After you've completed repairs make sure you maintain the system properly for longevity by cycling the a/c at least once a month, even during the winter. This will condition the seals and o-rings and provide lubrication through out the system. Since you're investing substantially, two other inspections I would do is the high side hose and the condenser.

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By the time you buy all the quality parts (which I agree are the only things you should use) you are already in very deep. The expense of repairing the A/C on my car far exceeds it's value. I sure wish it worked byt $2500+ to repair it just isn't a prudent move in my consideration. Considering that I bought this 1990 almost 8 years ago for $6000 and have put 80,000 miles on it, and I can still sell it for $3500, I'm happy. The only problem is that I just love this car so in all likelyhood, I will only drive it in the summer at night as I have done in the past.

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The flat rate manual lists the labor as being only 2.2 hours, make sure to replace the expansion valve, and the reciever/dryer when you have the evaporator replaced.

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BTW I bought my genuine Lexus evaporate car out of a car with 70k miles for $75, did your aftermarket core cost less than that?

The estimate for the new evaporator was $175 & the expansion valve was $45.

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