Any auto A/C experts?

[AllenW]

Originally Posted by Shellback

What they explained to me and what was done could be 2 different things.They said their SOP was to extract the freon, then refill to the correct amount. I can understand that so they know it is filled properly. Maybe by a fluke coincidence it cooled after that service. By the time I picked it up, it wasn't cooling. After it was back in the shop they told me it needed a compressor. Shortly later it was a clutch it needed. I know low freon will have the compressor to short cycle, but I imagine the pressure sensor could be bad and also cause it to short cycle. I know I waited over 2.5 hours for them to "change the clutch". Seems like an awful long time to do that. I'm halfway guessing that they may have changed the clutch and it still wasn't right. After the failed repair, he went into the service dept and spoke to them. Perhaps after that they put a more experienced tech on the case, and finally found the real problem and fixed it. Maybe a pressure sensor? Anyhow it's working correctly at present. A friend has been the used car manager there for the past 15 or 20 years.

These are not refrigerators that require a small precise amount, they have an accumulator/container that acts like a storage tank and that allows for some fudge factor on charge amount.
A good auto AC guy can charge by temp/temp and pressure.

imho

Al

[rwl]

Originally Posted by AllenW

These are not refrigerators that require a small precise amount, they have an accumulator/container that acts like a storage tank and that allows for some fudge factor on charge amount.
A good auto AC guy can charge by temp/temp and pressure.

imho

Al

You are pretty much correct, you could do it that way, BUT, you should see what a technician sees once in a while. Now with guys able to buy refrigerant at any store in WI, every time there is a problem guys just dump another can into the system, still not working, must need more. That and pressure switches with jumpers on them you name it.

Maybe not on the OP truck, but on anything a bit older or out of warranty I would probably evacuate the system and pull a vacuum. Get some of the moisture out of the system and start with the proper amount of refrigerant and go from there.

[AllenW]

Originally Posted by rwl

You are pretty much correct, you could do it that way, BUT, you should see what a technician sees once in a while. Now with guys able to buy refrigerant at any store in WI, every time there is a problem guys just dump another can into the system, still not working, must need more. That and pressure switches with jumpers on them you name it.

Maybe not on the OP truck, but on anything a bit older or out of warranty I would probably evacuate the system and pull a vacuum. Get some of the moisture out of the system and start with the proper amount of refrigerant and go from there.

I was a technician.
Worked A/C from about 1972, and I'd be hesitant to vacuum a system that had any time on it, been my experience auto A/C's either do leak or are about to.

But it would tell you if it was leaking easily with a micron gauge.
Different strokes.

Al

[rwl]

Originally Posted by AllenW

I was a technician.
Worked A/C from about 1972, and I'd be hesitant to vacuum a system that had any time on it, been my experience auto A/C's either do leak or are about to.

But it would tell you if it was leaking easily with a micron gauge.
Different strokes.

Al

I knew you were in HVAC I wasn't sure how much auto stuff you did. Seems the DIY guys don't tend to mess up home AC as much that I am aware of, but I only did auto AC.

I've seen compressors just knocking away because they were so overfilled.

[Shellback]

I just looked at my paperwork, it states they replaced the compressor. First they told me compressor, then just the clutch. Maybe they tried the clutch and it wasn't a fix, so they then did the compressor. Might explain why I waited 2.5 hours. Still working, so that's good!

[yarcraft91]

Originally Posted by Shellback

I just looked at my paperwork, it states they replaced the compressor. First they told me compressor, then just the clutch. Maybe they tried the clutch and it wasn't a fix, so they then did the compressor. Might explain why I waited 2.5 hours. Still working, so that's good!

That's all that really matters with a warranty repair.

I had a post-warranty repair done on my 2004 Suburban's A/C. That's when it matters more how long it takes to diagnose and repair something. In my case, the first guy just refilled with refrigerant. When the A/C failed again in 2 months, a second guy found the rear A/C condenser leaking and replaced it. Apparently Suburbans with rear A/C have some reputation for this failure.
That repair has held for several years.

[rivrtroller]

Originally Posted by yarcraft91

In my case, the first guy just refilled with refrigerant. When the A/C failed again in 2 months, a second guy found the rear A/C condenser leaking and replaced it. Apparently Suburbans with rear A/C have some reputation for this failure.
That repair has held for several years.

Would have been rear evaporatore core . Condensor is in front of vehicle . In front of radiator . High failure rate part due to rocks and road debris getting kicked up from vehicles in front of yours .

[yarcraft91]

Originally Posted by rivrtroller

Would have been rear evaporatore core . Condensor is in front of vehicle . In front of radiator . High failure rate part due to rocks and road debris getting kicked up from vehicles in front of yours .

Rear evaporator core. You are right.