View Full Version : Bringing a/c back from the dead
03-13-2008, 09:27 PM
Hello all I'm new here, did some looking around on the web and this is the biggest database of a/c info for a ranger i could find, so hopefully ill have better luck here. Heres my story. It all started with just a freon leak which eventually lead to an oil shortage in the system and a seized compressor... I bought a new compressor replaced that, and during recharge I blew a hole in the high pressure line (the 10" of rubber line coming out of the right side of the compressor if you are facing the engine bay) which may lead me to believe that the metering orifice may be clogged. but i cant seem to find where that is located at. Also I see some metal shavings in the lines at the disconnects, so im thinking some shrapnel from the old compressor made it down stream. So with some research I found a method of flushing the condenser by connecting a plastic hose to the high end connection, running that hose into a plastic bottle of mineral spirits and compressing the fluid in the bottle with air forcing the mineral spirits through the condenser. One more question i had is should i be able to blow through the receiver drier by mouth to check if it is clogged? Thanks for all your help!
It doesn't matter if the receiver/drier is plugged. Replace it whenever opening the system. And NEVER use your mouth as an air compressor. Virtually everything you come in contact with in this operation is at least moderately toxic.
The "metering orifice" (generally called the "orifice tube") is inside the lower evaporator tube. It can be pulled STRAIGHT out with a pliers. If you think you might twist it, get the special tool for it. This is a $2 part and there is simply no excuse for reusing it.
Even if your orifice tube is completely blocked, you shouldn't blow holes in the compressor lines. There is supposed to be a pressure relief valve, and the system is designed for 450 PSI.
Given the level of carnage, I'd seriously consider replacing everything that comes in contact with refrigerant. It isn't as expensive as you might think; I recently did this for a seized compressor for less than $400 counting refrigerant (R-134a), oil, and antifreeze.
Listen to Makg, he knows what he is talking about. I have learned alot from him and by applying myself to understand. Best bet, if you want to do it yourself, buy R134A manifold gauges, I bought the DVD on A/C at Autozone, that was very helpful. There is a flushing agent you can buy, but you must use the pressurized by air compressor canister to flush and can only do the lines,evaporator and condensor* (*if it is a Serpentine condensor, otherwise you must replace it). Drier and Orfice tube should be replaced anytime the system is opened.
You did not state it, but assuming you did, did you evacuate the system? If so, with what method?
03-14-2008, 03:29 PM
The previous posters are shooting you straight, and giving good advice. The only thing I can add, is sorry that you had a bad experience on the first repair attempt. Maybe you'll get lucky and get the compressor exchanged, but you really need to look at replacing the other stuff. Don't be discouraged, and good luck.
03-14-2008, 03:35 PM
Not trying to hijack here, but where is the drier/reciever? Is it the accumulator?
I think mine is plugged as well. It's the canister deal on the passenger fenderwell that's plugged. Thanks.
03-14-2008, 03:39 PM
i have serious reservations about mineral spirits for a flushing agent,never heard of such.tis not something i would do,i'd replace all the components first.
03-14-2008, 03:45 PM
Allen- that is it. Receiver, Drier, Accumulator are just different names for the same animal.
Skippy- good point. I picked my flush gun for around $25, and good parts stores carry the correct flushing agent to use in it. But with ALL new parts, you won't need to flush anything.
03-14-2008, 04:49 PM
That's what I needed to know. I think I need a new one because when I just did my motor/tranny swap I had the system evacuated and the lines were open. The accumulator was spewing stuff out of it (green) and then stopped, and then about 20-30 minutes later spewed again. It did this for a couple of hours as I was working on the truck. It seemed to be clogged and then relieve itself every so often.
It's the original one as far as I know and my Ranger is a 95 with TONS of miles on it. Towards the end of summer 2007 the air was'nt blowing that cold anymore, and the compressor is brand new. I bought it at AutoZone last year (2007) for the summer and the air was cold at first but as summer came to an end the air got a little warmer. If I replace the accumulator will this help? Thanks.
03-14-2008, 05:02 PM
Allen, there's better AC hands on here that can give you better advice on if the system will perform better, but it's a pretty much standard procedure to replace the drier any time the system is opened. It seems to me, that replacing the drier, and doing a proper evacuation and recharging can't hurt, and should help. BTW, your description of what the drier did, reminds me of the girl in the movie "Exorcist"! Pretty sick, huh?
Hardwareman, change the drier,if your system has been open for a length of time, it is better to buy new everything-hoses,condenser,drier,evap,orfice tube and compressor. Buy PAG oil,lubricate the o-rings with the oil as well before using them. Mix the proper amount of oil in the compressor and open the drier for a breif moment to put the oil in and reseal quickly, leave it that way and install that last. The reason the drier is the most important is as heat is drawn from the cab, the freon carries it out. Heat cools and turns to............moisture. This is that dripping of water effect, it "Dries" out the moisture. Cannot compress water.
The green stuff you are talking about is most likely either a stop leak or leak detector once put in your system. I could be wrong on this, but that is what it sounds like to me. More so on the Stop leak, seeing as how the uv leak detector is supposed to be removed by the drier, the same way as moisture, except you should see a slight green tint in the water dripping.
03-14-2008, 11:44 PM
So the accumulator and drier are the same thing?
It's kind of confusing because there's items listed on AutoZone's website that's not on my truck. It seems like all there is to my A/C is a evaperator, accumulator, condensor, compressor, and the hoses. Is that right? I don't have lots of cash right now because I recently became unemployed.
Will I be able to replace just the accumulator and the evaperator?
Yes, you can change just one item or two or all, I would inspect the lines carefully and look for fatigue and\or cracks. Add some oil to the drier (ask at the auto parts store for correct amount) and add it before installing the drier. Replace that Orfice tube as well. Pump the system for about 30 mins (at least -25 in. HG). Leave the gauges connected for another 30 min, and if you have the same reading as 30 min prior, should be ok to start filling the system with refrigerant.
Just remember, not taking the extra steps (flushing, not replacing parts that can't be flushed) can nickel-Dime you to death.
What vacuum to pull is a function of altitude. In Reno, you can't get -25 in Hg. That's lower than ambient at 6000 feet (ISA is just under 24 in Hg). At sea level, you should get at least -29 in Hg.
As a rule, it should be well under 1 in Hg above ambient. You can get ambient from a barometer or guess using the ISA. Or if you prefer a more rigorous statement, you want the absolute pressure to be well under (+)1 in Hg, with no discernable leakdown.
It's best to pressure-proof the system with dry nitrogen, but that's not easy to get ahold of at home. This way you don't suck a lot of water vapor through the drier. The last time I did this, I leak-tested the system using the vacuum method, with the old drier. Then I broke the vacuum (with air) and replaced the drier with the new one, and sucked it down to a hair's breadth off 30 in. Seems to be holding fine.
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