A/C system efficiency not so great. flush? electric fan?

Just wondering if a flush will help. I've recharged it a couple times since I've owned the truck for a few years now. Just recently charged it from pretty much empty and it just seems like it should be working better. Not sure of the efficiency of our ac system.. I assume its not the greatest like newer cars but.. I've got a temp gauge in the duct and I'm reading about 65 degrees at idle and about 53 driving at highway speeds. That's here in az where its 110 outside right now. I realize it's not very efficient at idle without an electric fan, but seems like it should be colder than that regardless. It also takes a good, Idk, 20 minutes driving before it finally cools down to a tolerable temp I'm the cab. Even then it remains on full blast. Then stopping at a light it rockets back up to 65 or so. So if I'm stopping at a convenience store or anything I always leave it running while I'm in. So yeah, just wondering if there's anything I can do to increase the efficiency. Couple thoughts are:

Take it in to be flushed

Pull evaporator and check for debris (I did this on a t100 and it was all gunked up) Not sure how easy/hard it is on the Tacoma.

Possibly install an electric fan in front of condenser? Not sure how viable this would be with the clutch fan. Would it interfere?

Anything else or input on the flush at least? Or is this pretty much the best ima get out of it? Anyone else have any accurate temp readings to compare?

 

I live in Las Vegas which is a similar climate but it took 10 minutes before I turned the fan speed down from high on my drive home this afternoon from work. I didn't have my thermometer on me so I can't tell you the temperature.

 

Hm. Well the thing with mine is, it's like 55 degrees IN the duct itself. But in the cab it's probly 70 or more. And doesn't seem to get any cooler than that especially if in stop and go, or making stops is even worse and it never cools down enough. It's tolerable, but my ac remains on full blast all the time. I don't remember it being like this last summer. I'm just wondering if a flush will help. I doubt it's the evaporator clogged or dirty. Could be. I'll look into taking that out and blasting the fins clean with high pressure air. But I'd like to get a flush IF it's suggested. Butdon't wanna pay to have it done if it ain't gonna help..

 

I'll check the temperature tomorrow after work when it's hot.

 

have you vacuumed it down before added refrigerant? You definately have a leak in the system. check all the connections, look for oil residue. I have a 1st gen as well, they definately have capacity to freeze you out no matter the outside temp.

 

Well I believe this is the 2nd time charging it in the 3+ years I've had it. If it's leaking it's super slow. But it's fully charged and not leaking that I can tell. Have checked for leaks with no luck. Even tried one of those hand held leak detector machines. And no I did not vacuum anything out. I just let the remaining charge slowly evacuate. Which I know is bad. But unsure if it affects the system doing that... Which is why I'm inquiring about a flush. I know how to charge it, but know nothing about how it really works inside. Ha. So I assume it probably needs a good flush then?

 

55 in the vent isn't to bad and normally you see 50 so you may just have air and moisture mixed with the Freon so its not all Freon in it and so it would cool as well.

often small tiny leaks like yours are leaking from the valve cores at the hose connections

my rule of thumb is its not a leak that needs fixing, or something you can probably even find, unless you need more then one can of Freon a year.

when Freon leaks it carries a thin film of oil with it so a spot that has a leak will have a dirty film around it like an oil stain covered in dirt

 

this guy knows what he is talking about.karl, you want to link my thread, go ahead.

 

I have had a thermometer in the duct itself since I've owned the truck just to monitor the efficiency of the A/C system. My truck is an 2009 dcsb with 130k miles, and currently the A/C system is performing very well.

The thermometer in the duct reads 40 degrees F when driving even when it is 100 + degrees outside. It takes about 5-10 min or so of driving for the system to bring the duct temp to 40 degrees F. The only time I see the duct temp hold in the 55-60F temp range is when I first start the truck, turn on the system, and haven't moved much such as in traffic at the beginning of my commute

 

well newer systems are more efficient so yours will act a "little" different, especially in the time it takes to cool down. newer more efficient systems run colder but take longer to get that cold

 

How do you make sure you are charging it to the proper level if you do not evacuate it and vacuum it down properly? A system that is even .20 lbs under, or over charged will have it's efficiency affected. I would be willing to bet that when you most recently charged it, you overfilled.

 

I agree, start with a fresh vacuum pull and see if it holds. Lot of questions can be answered with the results of this step.

 

So what does the vacuuming do? Is that just for testing for leaks? Or does it pull even more extra Freon out that may not have exited? Causing it to be kinda clogged? I have no clue what's involved besides charging it with a can of Freon with a gauge. I used the gauge that came with a can I got before. I didn't think it was full so I hooked up a second smaller can of Freon and charged it the rest of the way to full. And it didn't take much more at all. Probly 3/4 of that second can left... My brothers got the full kit of gauges and whatnot that I can use. Not sure if there's any more to it than that versus using the simple gauge and can.. Again I was probly just gonna take it somewhere and have it flushed and whatnot. Unless I can do it myself. Like I said my bro has the kit and a huge ads compressor. From what little I read on flushing, it says it needs compressed air?

Edit: nvm. I read up a little more on the flushing subject. Seems it's way more involved than I'd like it to be. I think I'll just take it in sonewheres and have it flushed. See what happens. Doesn't seem like it's a diy-friendly type job.

 

i just went hru this with the help of another member. Like you, i would just add refrigerant and call it good.

basicly, your system operates the best when thereis only refrigerant and a small amount of oil. Your system has refrigerant and atmospheric air mixed in with it. When you vaccum down the system, you get rid most of the contaminats, thus you can charge it with refrigerant only. The vacuuming down the system gets rid of everything except the oil. Once done you can start fresh.

You will have to buy a few specialized tools.

here is the thread that I made with the help of a member.
Home

 

That didnt work. I'll just write it out.

A/C r3build

Lots of good info.

 

If you dont know about AC systems and you want your truck running at peak efficiency, I recommend you take your truck in to a reputable place that specializes in AC work.

That said, I think your AC system is working fine (though it could be slightly better). I'm like you and prefer to do most (if not all) work on my truck myself. I've worked on the AC system of a few different cars and have learned alot (but no way do I claim to be an expert). Do your research. Know how much refrigerant and the type of oil your AC system needs. Youtube has alot of information. Check out this youtube playlist. I suggest watching all the videos and not skipping any bits.

Heres a few things I have learned
- 40 degree temperature reduction below the outside ambient temperature is sufficient. (110°-65°= 45°F reduction ).
- The accumulator drier ($10 part) should be replaced any time the AC system is exposed to atmosphere (left open) for any significant time. It will remove moisture from the system.
- There is a sticker under the hood of all vehicles that indicates the type and amount of refrigerant your AC system uses
- Properly filling up the AC System consists of the steps below:

1. Evacuate system properly (Take it into a shop to suck the refrigerant out).
   
2. Apply a vacuum to the system using a set of AC gauges and a vacuum pump.
3. Close AC system and wait 30+ minutes to ensure vacuum is not lost. If pressure increases, you have a leak. (most leaks are on the hi or low pressure schrader valves.)
4. If no leaks, fill AC system up with specified amount of refrigerant, oil if compressor was replaced, and dye for good measure. Use low pressure side only.
5. Fill slowly, shake and turn can of refrigerant upside down every few seconds. Use a weight scale to monitor how much refrigerant has left the can and gone into your AC system. Make sure to bleed a small amount of refrigerant out of the entrance hose (normally yellow) to prevent air/moisture from going in AC system. (this is the only time you should intentionally let refrigerant into the atmosphere)
6. Stop adding refrigerant when the can's weight has dropped for what your AC system require (e.g. if you have a can that weighs 30 oz and your AC system call for 28 oz, close the low pressure side and stop when the can is 28 oz lighter).
7. Screw caps back onto low and high pressure ports. Ensure a good o-ring is in the cap.

 

Hmm. Well I think my brother has a vacuum machine I can use. Seems like he's helped me do this before now that you explain it. Probably on a different vehicle years ago.. I'll look into those steps you provided. I believe we've got the tools to do all of that minus getting the system evacuated first. Would big o or Napa do this service? Only two shops in town. Anything else would be 30+ miles to get to.

 

If the refrigerant is already gone, you don't need to have a refrigerant reclaim machine remove something that is not there. It's only illegal to knowingly vent refrigerant to the atmosphere. You can move straight to the vacuuming down the system step.

Watch those vidios, they really help.

 

Big-O might but I'm not sure if the chain autoparts stores provide AC evacuation service. I dont think so but its worth calling them to ask.. Any place that works on AC systems will though to include a dealership. I am cheap so I personally would call around and see who can do it cheapest. Also, look on ebay or Amazon for bulk refrigerant.

$49.95 - DuPont Suva R134a Refrigerant 12oz (Pack Of 12) You should only need 2-3 12oz cans but youll have more on hand later. Monitor the weight of the can as you add it.
$6.95 - Dupont Freon 134a for Mobile A/c Systems 12 Oz Can

$20 Four Seasons 33589 Filter Drier

$14.46 - Four Seasons 33589 Filter Drier Make sure it fits your truck

You will only need to replace the accumulator drier if its been exposed to atmosphere (empty) for awhile, but it wouldn't hurt to replace it if you've been tinkering with the system over the years.

 

Sub'd.