rear AC condenser shot... can I cap the lines? (5 Viewers)

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I took mine to a lexus dealership a couple of months ago and he told me the rear ac evap was bad. The dealer I bought it from has a shade tree mechanic that they use. he just replaced my rear AC evap for free. 5 hour job. he told me the rear unit looked fine, but he replaced it anyway. he also saw that there was a shrader valve up front that was bad. Im hoping this fixes it!!! truck has 270k miles on it...
 
Had same issue this weekend on trip to Big Bend National Park. Took to dealer and they said the rear A/C will be first to show signs of low freon level by blowing luke warm air. They charged it, put dye in, and were unable to find leak. Going to run for a few days and take back for them to check again (although, after reading some of this thread and having just installed a drawer system, I'm not exactly sure how they were able to check the rear A/C components in the quarter panel...).

This exactly! I decided I might as well waste a can topping off the r134a, and add dye to see if I can find a leak. I noticed I was real low, after 18oz, I noticed the fan in the front kicked on.. got in the rig, rear AC is working great!

If I have a leak, it appears to be small since the AC has been working fine for over a week. Finding a leak in either of the evaporators is not easy at all, so time will tell. I'm just glad my kids aren't sweating anymore.
 
This exactly! I decided I might as well waste a can topping off the r134a, and add dye to see if I can find a leak. I noticed I was real low, after 18oz, I noticed the fan in the front kicked on.. got in the rig, rear AC is working great!

If I have a leak, it appears to be small since the AC has been working fine for over a week. Finding a leak in either of the evaporators is not easy at all, so time will tell. I'm just glad my kids aren't sweating anymore.
Been driving around with front and rear AC on max and windows down trying to work the AC and not freeze to death. Hoping the leak shows itself!
 
update... Rear evap replaced by a shade tree mechanic... for free. AC worked great for 3 weeks. Now blowing warm air again. I recharged with dye... AGAIN. will look under truck with black light. frustrating... Mechanic said rear evaporator looked fine. I traced the rear AC lines to the rear of truck. almost entire length is covered in a foam sheath. I wonder if I should cut the foam away to look for pin hole leaks. Its going to be 90 degrees this week, so the AC is going to be more critical...
 
I just capped my rear evap 2 weeks ago. 2 leaks - first under the front DS wheel well the second where the suction line heads up into the evap unit. The mechanic could have replaced the front line but said that the rear was almost impossible. Aluminum tubing and road salt are not a good combination.

The front blows cold - happy wife, happy life.
 
I'm getting about 3 weeks until the truck AC no longer works. just got a UV light for 10 bucks on amazon... hopefully the light will show the leak... truck has 275k miles on it and drives like a freaking top other than the AC issue. Would love a permanent fix!!!! sucks because this is the family hauler and downtime is a huge pain for us...
 
There is nothing at all complicated about working on the AC system except for the recovery of coolant if your system is charged. As you all know I'm sure, it is illegal to vent coolant into the atmosphere. Once you've dealt with that little issue in whatever way your conscience allows, removing and replacing parts is easier than working on just about any other part of the vehicle. Once you have a little understanding of what the parts do, you can diagnose issues pretty quick. Even if you had to replace the Evap core itself, that's a 130.00 part from Rock Auto in the Denso brand (OEM).

Usually with rear AC on Dr T trucks, it's a line that fails due to corrosion. The first thing to check with your lamp is all of the connection points, as the O-rings can on occasion fail and leak. Also the schrader valves in the hi and lo service ports. They look and act exactly like tire inflation valves on your wheels. They can be simply unscrewed and new ones screwed in. For the record, my AC quit on my 80 and it was just a schrader valve that failed, allowing the coolant to leak out. 3.00 and a recharge and I was ice cold again.

Remember that the evaporator coils are exposed to outside air, meaning they take in atmospheric air, there is no filter in front of them to keep them clean like on your home unit, they often get covered in leaves, dirt, dead mice, whatever. You can and should clean them thoroughly when you work on the AC system, it's also not complicated.

Any time you open the system, you should replace the drier (on 100's its a desiccant element, meaning you don't replace the housing, just the insert that goes inside it), which is a 14.00 Denso part that removes moisture from your system. When moisture is present, the coolant inside has a tendency to freeze up, reducing its efficiency, that's what the drier prevents.

If your vehicle is as old as most of these are, and you do open the system, do yourself a favor and replace the expansion valve too. Its simple, held on by one or two nuts, and two o-rings. All of these parts are available from Rock Auto in the OEM (Denso) brand. If you replaced the drier and expansion valves, you'd be looking at a total of 30.00 worth of parts, including the generic O-ring kit.

It would suck to find a leak, repair it, then have your system freeze up two weeks later due to moisture.
 
I would pay someone a $1000 to fix the (@#*( AC... I get angry texts from my wife when I run out of coolant.
 
There is nothing at all complicated about working on the AC system except for the recovery of coolant if your system is charged. As you all know I'm sure, it is illegal to vent coolant into the atmosphere. Once you've dealt with that little issue in whatever way your conscience allows, removing and replacing parts is easier than working on just about any other part of the vehicle. Once you have a little understanding of what the parts do, you can diagnose issues pretty quick. Even if you had to replace the Evap core itself, that's a 130.00 part from Rock Auto in the Denso brand (OEM).

Usually with rear AC on Dr T trucks, it's a line that fails due to corrosion. The first thing to check with your lamp is all of the connection points, as the O-rings can on occasion fail and leak. Also the schrader valves in the hi and lo service ports. They look and act exactly like tire inflation valves on your wheels. They can be simply unscrewed and new ones screwed in. For the record, my AC quit on my 80 and it was just a schrader valve that failed, allowing the coolant to leak out. 3.00 and a recharge and I was ice cold again.

Remember that the evaporator coils are exposed to outside air, meaning they take in atmospheric air, there is no filter in front of them to keep them clean like on your home unit, they often get covered in leaves, dirt, dead mice, whatever. You can and should clean them thoroughly when you work on the AC system, it's also not complicated.

Any time you open the system, you should replace the drier (on 100's its a desiccant element, meaning you don't replace the housing, just the insert that goes inside it), which is a 14.00 Denso part that removes moisture from your system. When moisture is present, the coolant inside has a tendency to freeze up, reducing its efficiency, that's what the drier prevents.

If your vehicle is as old as most of these are, and you do open the system, do yourself a favor and replace the expansion valve too. Its simple, held on by one or two nuts, and two o-rings. All of these parts are available from Rock Auto in the OEM (Denso) brand. If you replaced the drier and expansion valves, you'd be looking at a total of 30.00 worth of parts, including the generic O-ring kit.

It would suck to find a leak, repair it, then have your system freeze up two weeks later due to moisture.

good post my rear ac is blowing warm and front has been freezing for a year so it can't be a leak, something in rear ac is broken and I'll look into replacing those 3 items (drier, evaporator, expansion valve).
 
Just going to throw in my 2cents. I had an issue where the front AC worked fine, and the rear AC starting blowing luke warm air and not a single drip from the rear evap. I was sure it was the expansion valve in there was bad.. hooked gauges up to the system just to see what the system was telling me... and noticed I was fairly low on R134a.. threw in a can, and all the sudden the rear ac started working again.

In other-words, the front AC can still blow somewhat cold with the rear not really functioning at all... all because it is low on freon.
do you put the coolant in a different spot for the rear? if so , where?
 
I know that this is an older thread. However, it was posted that typical issue with AC line leak can be found in the area behind the front passenger side wheel. Does anyone know more about this? Is this visible from under the truck? Does one have to take off the wheel well inside to see this?
 
I know that this is an older thread. However, it was posted that typical issue with AC line leak can be found in the area behind the front passenger side wheel. Does anyone know more about this? Is this visible from under the truck? Does one have to take off the wheel well inside to see this?
Your best bet is dye and a UV light. Recharge and then look at night.
 

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