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- Dec 25, 2005
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Following...as I'm now dealing with same issue. I have a $0 deductible Toyota warranty for another year, so I am eager to find the source of leak.
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- Thread starter
- #22
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...
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.
- Joined
- Dec 25, 2005
- Threads
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- Messages
- 1,550
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!
- Thread starter
- #25
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.
The front blows cold - happy wife, happy life.
- Thread starter
- #28
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.
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.
My AC was leaking badly. I'd charge it and it would last about 4 weeks. The tech noticed a greasy spot on each rear line right as it bended up at the firewall. We cut both lines and capped them, charged system, still blowing cold about 3 months later. Amazon.com: Airsept 76505 AC Block Kit: Automotive
Amazon.com: Airsept 76503 AC Block Kit: Automotive
Amazon.com: Airsept 76503 AC Block Kit: Automotive
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).
do you put the coolant in a different spot for the rear? if so , where?
The front and rear AC systems share the same supply of refrigerant/compressor/condenser. Search around here, or look at the FSM to get an idea of how the AC system is plumbed.
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?
- Thread starter
- #36
Your best bet is dye and a UV light. Recharge and then look at night.