Recharging Air Conditioning
 

My gf has a fit and the AC recently went out. I'm fairly familiar with cars, and would hate to pay someone $150 to do something I could do. I found a DIY online and seems to be about right, but I wanted to check here for any tips or recommendations before starting.

Here is the DIY:
DIY: How to Recharge Your Cars Air Conditioner | Milk Your Money

Any thoughts are appreciated. If there is a DIY here, I missed it when searching.

if the ac isnt working, that means that there is a problem that caused the refrigerant to leak out. recharging the ac wont help anything until you find/fix the problem.

also, leave recharging your AC to the pros. assuming that you have a leak in your ac system, the leak also allowed air to get in. by leaving air in your ac system and just adding refrigerant, you are not going to get the same result since air is taking up volume in the ac ssytem and not allowing as much refrigerant to be added. the lines must be vaccumed out first. unless you plan on buying a pump, you cant do this.

How old is her Fit? Any chance it would still be covered under warranty?

What you are trying to do is done all the time. The squeeze trigger type shown is what I recommend. The cheapest place to buy them is at Walmart. Also the cheapest place for additional cans is also Walmart (except in Wisconsin). I have one vehicle that leaks about 1 can (12oz) every year. I'm too lazy to go find the leak so once a year in the spring I add about 12 oz. to the system and it lasts all summer.

The one thing not mentioned in t he article is if the system is completely empty, then you need to evacuate (vacuum) the system and check for leaks BEFORE adding additional R-134. Before adding R-134 read the gauge with or without the engine running. If there is any pressure at all then all of the R-134 has not leaked out, outside air did not get in, and you are ready to charge you system yourself.

Some other hints:

I usually shoot for about 45 PSI with the engine running, the A/C running at maximum with the fan on high, and the compressor running. That pressure will vary some depending on the outside air temperature. If the compressor is cycling, read the pressure only when the comporessor is running. It is normall for the compressor to cycle occasionally. As you increase the amount of R-134 in the system, the compressor will cycle less often. Do not overcharge trying to eliminate the cycling as the system will run warmer when you have finished if it is over charged.

As you are filling the can will turn cold. That is normal. The way to tell if the can is completely empty is to feel the temperature of the can. If it is still cold then there is still some liquid in it. If you put your hand on the top of the can and BRIEFLY invert the can you can feel the cold liquid inside it. At the point where the top of the can no longer changes temperature when inverted, the can is empty. It will take several minutes (maybe 5 or so ) to completely empty one can.

In the past we always charged the AC system using pressure measurements. These days AC SYSTEMS ARE CHARGED BY WEIGHT. So if you take yours in they will pump out all of the R-134 and add a given amount back in to match factory specs. You can do it this way but the pressure method still works, so have at it. I fill AC systems both ways.

Good Luck. It is not a difficult job. I have done it in a Walmart parking lot many times.

You can find hundreds of posts on A/C problems with Fits, and the cause is almost always a tiny hole punched in the A/C condenser by a rock bouncing up from the road. Fits have absolutely zero protection from rocks because of the terrible design of the lower grille.

The above member is right- you can refill the A/C every day and it will do no good unless the leaky condenser is replaced. This will cost you at least $700.00 at a Honda dealer, and leaky condensers are NOT COVERED under warranty. You can buy new Honda condensers on eBaymotors.com much cheaper than you can at any dealer, but it would still be best to have the system purged and filled by an A/C pro. This would be cheaper at an independent foreign auto repair shop (that does A/C work) than it would at a Honda dealer.

Once you get all of that done, protect your investment by installing some sort of mesh grille material to deflect the rocks from the condenser. There are also hundreds of posts on that subject. eBaymotors has a bunch of aluminum and stainless steel grille overlays that are easy to install, guarantee that rocks can't hit the condenser, and some of them even look great on the Fit grille. One of the forums sponsors, Zeta Products, has a nice set of stainless steel grille protection overlays at a good price.

Honestly, if you can pay 150$ to have your AC repaired, I'd say that's a good deal. AC work is complicated because you have the interaction of chemical (refrigerant), mechanical (pump and vaccum) and electric (thermostat, wiring) for the system to work. You can refill the AC all day but if your AC clutch is not working, it still won't come on.

If you plan on doing a DIY, I'd definitely get a set of manifold gauges (50$) and then try and rent a vacuum pump. Connect the gauges and pump and suck out all the air and moisture until you get a vacuum in the system then leave it as is for 30 mins. If the vacuum was not maintained then you know your system is compromised. One solution then is to fill the system with refrigerant and dye and then try to find the leak with the dye. Once the leak is found then you can try and fix it. All this would be null though if your problem was with the AC compressor clutch so unless you really know AC, I would pay 150$ in a heartbeat.

The cheapo solution is to just put in some more refrigerant and hope for the best but that is environmentally irresponsible and I think if it's leaked bad enough for outside air and moisture to get in the system, then I believe the mix of moisture and refrigerant in the system could damage the system even further.

Best of luck to you.

Nice suggestion, but OP is long gone as well as the car:)

Wow! Embarrassing! I usually only comment recent posts. I wonder how this one turned up in my browser.

Thank a spammer (whose off-topic spam post has since been deleted).

Yes I saw that post. It was a guy from Texas trolling for his AC repair business. That is why I never commented. The OP was over 2 years old.

Oh well, he is gone now.

Thanks for all the great info. I have a 2011 honda fit the ac stopped working had it to 3 different shops all say the same thing everything checks out but no cold air. I kind of gave up at this point and just drive with the windows open. Systems not leaking compressor works system has been purged and recharged 3x. Wondering if there is a filter or something that may be blocked? System use to cycle on and off before completely died.

What you are saying makes no sense. How can everything check out OK if there is no cold air coming out of the vent? I cn nto imagine that you took it to three different incompetent shops in a row.

Did they stick a thermometer in the vent ? What did it read? Did they check to see if the evaporator is getting cold?. Did they check to see if the air was flowing through the evaporator? Was the compressor running (cycling)? If so what is the ratio of on to off time? Is one line going into the evaporator warm and the other one cold?

I can not help you much because you have not supplied us with enough detail.

They basically all did the same thing emptied the system, recharged it and no cold air comping out. They than hooked it up to the computer and couldn't figure out what was wrong so basically got charged a recharging fee. Unfortunately I can't tell you much more than that as my wife took the car each time. I can tell you that the compressor seems to cycle on and off about every 5 to 10 seconds other than that I haven't messed with it too much. I know a decent amount about cars have repaired suspension systems, timing belts, head gaskets etc.. but don't know much about ACs. Any tips on any quick checks I can do myself at this point would by helpful. Also there is no cold air coming out of the vents even right after the shops emptied and recharged the system, they also said it held pressure no idea of the high and low side measurements though.

Well that gives us a place to start. It sounds like R-134 in the system is probably correct The compressor will cycle if the evaporator is not exchanging the heat and this is a normal operation. You now need to see if the evaporator is getting cold. You need to find the two hoses going into the firewall that carry the r-143 (refrigerant) to and from the evaporator. When the AC is on, one of those hoses should be a little warm and the other should be cold. If that is what you have then the evaporator is operating correctly. We need to look for an air flow problem meaning the outside or recirculated is not flowing across the evaporator. I do not have a Honda Fit here right now to look at so I can not tell you exactly where those hoses go into the firewall and to the heater / evaporator assembly.

I am thinking that you are going to find a stuck air door somewhere in the HVAC assembly.

Sorry been real busy lately, finally got a chance last night to check over things. Right now the compressor kicks on and just stays on. Both hoses going through firewall are not cold at all. Also when I hook up a gauge to low end pressure line pressure slowly climbs from about 40 psi to 110 psi. Once at 110psi it stays there.

Sounds like it could be a bad expansion valve that is stuck open allowing too much refrigerant to flow into evaporator. This would give you a high high side reading. If you had a compressor failure, you might get a low high side reading. I'm assuming that your system was properly evacuated and filled and that your cooling fans for the condenser are working. A clogged condenser keeping air from cooling it could do this.

What is your high side reading? Are you racing the engine when you take your readings or just letting it idle?

How cold should the low side lines be? Tested last night at about 70 degrees ambient, the cold lines were indeed far colder than the hot ones (good) but also not truly frigid to the touch ( ... good? bad?)

For my car I suspect either low refrigerant OR a stuck hot/cold air mix door (but the control moves just fine ...). Really not looking forward to taking this one to the dealer. Warranty expired a week ago. I expected better from my fourth car. Thanks, Honda.

Feeling the temperature of the cold return line is not really a known measurement. Feeling the lines for a hot and cold difference is a good check to see if the expansion valve and evaporator are working. The gas at this point has already absorbed some heat as is went through the evaporator.

If you want to check for cooling at the evaporator, use a thermometer in the closest air vent. The temp with the fan on high and the vehicle running down the road should run around 40 degrees colder than your intake air. Intake air is either inside the car or Outside Air Temperature (OAT) depending on where you have the control set. In all cases the vent temperature should not go below about 40 F. If it does the evaporator will freeze up with condensed moisture out of the air. Most of the time this lower cutoff is around 45 or 46F.

Low R-134 levels will cause to system to cool at a LOWER temperature. This will continue until the R-134 levels are so low that there is not enough gas left in the system to compress. At that point the system will cease to work at all. Most automotive AC systems sense the lower pressure and shut down themselves. Some compressor cycling off and on is normal as the low (and high) pressure limits are reached.

There are many factors that affect the difference from ambient temp to evaporator (vent near evaporator) temp:
1. Outside temp. at 70 degree ambient, you would get less difference than at 90 degrees ambient.
2. High humidity will reduce the difference in temp.
3. Idling engine will reduce the difference in temp
4. High interior fan speed will reduce difference in temp.
5. Your blend door must close off heat. You should hear a slight clunk when you rapidly move your heat control to "COLD" If you don't, you can access the linkage from the glove box. Just move the glove box as if you were replacing the cabin air filter and you will see the cable to the left and can check its operation.

If it were my car and it was 90 degrees outside, fan on high, engine at 2000 RPM for a few minutes, both condenser fans operating normally, moderate humidity, and I measure below 60 degrees at vent nearest the evaporator, I'd call it a day. If temp is higher, get some manifold gauges. If both sides are low, you can trying adding some R134a, but there is some risk. A good AC place may insist on recovering the refrigerant, drawing a vacuum, and refilling by weight. That is the most accurate way to get the proper amount in. If there is a leak (that is probable unless under-filled from factory), that must be repaired first.

My 2009 Fit is adequate at 95 degrees and has always been that way, whereas my 2015 Forester is superior. Simply put, the Fit does not have a particularly powerful A/C, but it is sufficient.

Is it normal for the compressor to spin almost non-stop? Mine doesn't cycle very much and I know the condenser fan is working well. I suspect this is why my fuel economy tanked when I started using A/C. I just changed the cabin air filter but I haven't tested vent-to-exterior temperatures. (Not accustomed to A/C usage.)