Pickup AC Repair

dhermesc

Well-known Member
I recently bought an older (1990) F150 that was in excellent condition for my teenage son to drive. AC was dead and I paid a shop to convert to R134 and recharge. They charged me $200 for the conversion and recharge. The charge lasted about 3 hours before the AC was blowing hot air again. Brought it back to them and they said the condenser had a hole. The said they'd need about $500 to replace the condenser and recharge.



Question - shouldn't they have caught the hole in the condenser (or at least that the system was leaking) when they put a vacuume on the system to purge the R12? I thought the $200 was a bit high - but thought it was worth it to have it done right - up until I found out it was wasted. Seems almost like I could have bought the conversion kit from Wal-Mart and charged it for all the good they did.


The condenser is $74 and looks not to difficult to install. Do it my self and have a better shop evacuate the system and charge?
 
I'd do it my self and then have a shop vacuum it down then put the 135A in my self. Now days you can buy the stuff for around $40 and that has the gauge built into the can
 

Hole in condenser should have been located before any coolant was added when AC system was evacuated after changeover from R12 to 134A and system wouldn't hold a vacuum.
 
(quoted from post at 08:22:17 07/27/15) I recently bought an older (1990) F150 that was in excellent condition for my teenage son to drive. AC was dead and I paid a shop to convert to R134 and recharge. They charged me $200 for the conversion and recharge. The charge lasted about 3 hours before the AC was blowing hot air again. Brought it back to them and they said the condenser had a hole. The said they'd need about $500 to replace the condenser and recharge.



Question - shouldn't they have caught the hole in the condenser (or at least that the system was leaking) when they put a vacuume on the system to purge the R12? I thought the $200 was a bit high - but thought it was worth it to have it done right - up until I found out it was wasted. Seems almost like I could have bought the conversion kit from Wal-Mart and charged it for all the good they did.


The condenser is $74 and looks not to difficult to install. Do it my self and have a better shop evacuate the system and charge?
es....they should have caught it when they evacuated the system. There is no way they could have drawn a vacuum with a hole in the condenser. It should be replaced anyway. I've found they cool way better if you replace the condenser on older stuff.
 
Does/should the dryer/accumulator need replaced with the condenser - or does it matter much on an older unit like this?
 
For $200.00 you probably got basic conversion kit-[fittings, 3 134a, barrier oil we hope.] & labor makes this deal pretty fair. As far as leak showing up under vac. not always,and maybe it blew out with the 134a higher head pressure. yes, dryer/accm. should be replaced. If you can replace condenser yourself, do so & see if shop will evac/recharge @ a good rate. having tried some conversions myself, I have had very little success with just drop-in refrig. & should have 0-ring replacement, compressor drain/flush, etc, barrier hoses, etc. depends.
 
It's possible that a corroded spot on the condenser blew out under the pressure of hot refrigerant, yet was air tight with only vacuum on the system.

I would replace the condenser myself, rent / buy a vacuum pump and gauge set to recharge it myself. Would cost less than paying to get the job done and them you have the tools for the next "do it yourself" AC repair job.

You may have lost most of the refrigerant oil through the leak, so I would add atleast 4 oz of the correct oil(Ester ?) through those neat little interdynamics "oil charge" cans sold at most auto parts stores

I have maybe $250-$300 in a used vacuum pump, a cheap gauge set,leak sniffer, can tappers, a vent thermometer and a "how to do AC repairs" book. Have done all my AC work on a fleet of cars, pickups and farm equippment for the last 30 years. Saved myself many thousand dollars and got it done when I needed it.
 
Sometimes, depending on the type of leak, they will leak with pressure but not vacuum. 250psi is much more stress on a small leak than 28in hg
 
Yes, a good dryer makes a difference on any age system, as the old one is likely about saturated with moisture and trash, cheap insurance.
 
The system was empty when they got it. As a result their responsibility was to make sure they knew where the refrigerant went before modifying the components. Three hours is warranty work. Sniffer testing after repair is also reasonable. If the condenser was leaking it would be ugly oily and dirt filled at the leak (almost every time!) putting in a condenser you find for your price should be OK their workmanship was not operational. Jim
 
Having done air cond work for over 40 years now, leaks will and do escape you. Anyone that says he never had a leak get away from them has not done very many systems. A vacuum will not show up all leaks, sometimes shows leaks on pump seals that do not leak under pressure or in normal operation. Dye shows up some otherwise undetectable leaks and misses others completely. NO ONE WAY to find leaks is fool proof. High pressure nitrogen works sometimes, and then again it don't. Refrigerant sniffers find some and miss some. So, you just have to go with the flow if the one who worked on your system seemed capable. The change over for $200 sounds reasonable to me. I don't charge near that much but I work cheap & don't have the overhead a shop does. I also pick my jobs and customers.
 
Having done AC work for nearly 10 years now, all I cans say is those that have stated that the leak could have easily slipped by them, for any one of several reasons, have given good advice. In fact I've got one on our '97 Suburban that had eluded be three times now. I've watched it hold a vacuum every time. The first charge lasted nearly a year, the second only a week, and the third lasted nearly a month. I've added dye to the system and still can't find anything showing up. I'm just about to the point of changing the compressor just because, especially when this system takes nearly 4 lbs every time I charge it.
 
A vacuum can actually seal a loose piece of oring and pressure will do the opposite that is why the proper procedure is to do both. There are leak detectors (sniffers) that will find leaks that will leak as little as 1/4 ounce per year but if it leaked out in four hours you don't need a very sophisticated tester to find it. Leaks can be very difficult to find that is why there are so many different methods of looking for them. The condenser could have popped a hole as soon as you left the repair shop.
 
Wal-Mart sells them for $44.00



http://www.walmart.com/ip/EZ-Chill-AC-Recharge-and-Retrofit-Kit/16888792
 
Can you really convert from R12 to R134a with only the Walmart / Interdynamics $45 retrofit kit ?? The answer is sometimes yes.
The Walmart kit contains the R134a conversion fittings, a can of 8.5 oz of ester oil and refrigerant, plus another 2-3 cans of R134a, and a tapper / charging hose.

They tell you to vac the system, add the 8.5 oz of oil charge on top of what remaining mineral oil is in the system, then add enough extra R134 until it is cooling good.

Just to satisfy my own curosity, I converted my old 79 Dodge full size van using one of the interdynamics kits, I knew the system was working and only low on R12, so I experimented , doing it the way interdynamics said. Only thing I added was to vacuum the system for 2 hours to get the old dryer as dry as possible.

The conversion worked well, being done on an otherwise good working system. It cooled well and would only leak a few oz per year, I ran it that way for near 10 years.

If the system has had a compressor fail and the system is full of metal trash, you MUST flush the system and replace the dryer along with the compressor if you want it to work / last.

Back in the day when the big change from R12 to R134a was the deal I followed a couple of AC repair sites where guys who did AC for a living, soon found out what would work and what would not, and shared that with us shade tree AC guys.

What had everyone in an uproar, was that originally they said you had to change almost everything to do a successful R12 to R134a conversion, big bucks.
Had to change compressor, dryer, all hoses, and condenser.
After about a year of trying, the AC guys found it was not really that bad. In most cases, your old compressor, hoses, condenser and expansion valve would do just fine.

The old R12 hoses, if in good condition, would work fine, as years of mineral oil running through them made a pretty effective seal that leaked very little R134a. For that reason, many recommended NOT flushing unless a compressor had failed, as the flush removed some of that mineral oil stop leak coating.
It turns out that on an otherwise good AC system, the shade tre mechanic could do a reliable R12 to R134a conversion for a bout $100 in parts and his own labor IF he had his own basic AC tools like a vac pump, gauge set and vent thermometer. A parts store " Fix your AC" book helped understand how the systems worked and often gave oil capacity specs and other useful stuff.
Another thing that has been good for my shade tree conversions, is to put a can of hose/ seal/ Oring conditioner in to slow or stop minor rubber part leaks in old R12 systems.

One bad thing about not removing all the old mineral oil, is that the condenser and evaporator area occupied by that old oil, does not cool . On a system with plenty excess capacity that means little, as the system still has enough capacity.
If the system is marginal, like on a Dodge caravan, then that less cooling might make or break the deal.
 
For this conversion to last a few years ,the system needs to be taken apart and flushed out with a solvent. Then get a rebuilt compressor, a new accumulator or dyer, orifice tube or expansion valve(depends on which system set up you have) and add proper oil and type of oil. Replace all orings. Also fix/repair leak then pull a vacuum,then pressure test with nitrogen to check for leaks and then charge system with R134a.

This system will hold about 80% R134a compared to R12. The system needs to be flushed cause the oil used in R12 reacts with oil used in R134a . Some of the older compressors will leak with the use of R134a. Its not that hard to DIY.

This is one of those things you can throw a lot of money at before you get all leaks and issues resolved ( do not ask how I know this). Go to half price books and get a AC repair manual and read and read some more. To pull a vacuum go to harbor freight and get a compressor operated vacuum device/puller. You can get gauges there too.
 
I would think the compressor seal is leaking instead of the condensor unless they sniffed it and found the leak in the condensor.
 
(quoted from post at 09:22:17 07/27/15) I recently bought an older (1990) F150 that was in excellent condition for my teenage son to drive. AC was dead and I paid a shop to convert to R134 and recharge. They charged me $200 for the conversion and recharge. The charge lasted about 3 hours before the AC was blowing hot air again. Brought it back to them and they said the condenser had a hole. The said they'd need about $500 to replace the condenser and recharge.

Sometimes the Schrader valve on the charge fitting will stick when the charge hose is removed and go un-noticed for some time.


Question - shouldn't they have caught the hole in the condenser (or at least that the system was leaking) when they put a vacuume on the system to purge the R12? I thought the $200 was a bit high - but thought it was worth it to have it done right - up until I found out it was wasted. Seems almost like I could have bought the conversion kit from Wal-Mart and charged it for all the good they did.


The condenser is $74 and looks not to difficult to install. Do it my self and have a better shop evacuate the system and charge?
 
OK, I'll add my two cents here....
Replacing the condenser is not a difficult job. Recharging the system is best left to the professionals. Yes, you can buy those recharging kits at most auto parts stores, but the success rate with them is low. Mostly because of untrained and inexperienced folks simply do not understand refrigeration, and have some mistaken ideas about how to repair a non-working A/C system.
There is a reason for evacuating a system and replacing the receiver/dryer before recharge. The receiver/dryer acts as a filter for the dirt in the system, and absorbs moisture to keep it out of the wrong places. It also holds excess refrigerant and oil.
I would suggest that at the minimum, you get a set of gauges and a vacuum pump. It is money well spent.

As to oil: First thing to know is that the oil circulates with the refrigerant. R-12 uses a mineral oil that will not circulate with R-134a. As such, you do need to replace the oil in the system with an ester oil. Ester oil will circulate with the R-134a, and will not react badly with the mineral oil that will inevitably be left in the system. Not advised to use PAG oil, as it will potentially react with the mineral oil.
Evacuating the system is necessary for two reasons:
1) To remove the air from the system. Why? Because air is a non-compressible gas in this application, and air in the system can prevent cooling. In order to cool, the refrigerant has to be compressed to a liquid and then metered into the evaporator and evaporated in order to cool. Air will not liquefy at the pressures found in A/C systems.
2) To remove as much moisture as possible. Moisture in the system can cause corrosion and compressor failure. It can also cause icing if it gets into the metering device.
Contrary to another post, you do not have to replace everything in the system or flush everything with solvent. Replacing the receiver tank and condenser in your case should be sufficient. Add to that evacuating the system and adding some oil.
I have converted many systems to R-134a over the last 25 years or so, and never had to get too extreme with any of them. They all worked as long as they needed to.
 
the kit for $44.00 @ walmart is prob. a good deal. expect the same results as you would from fix-a-flat, slime, restore, radiator stop leak, etc.
 

I don't know the circumstance they had to work under...

Did you ask for a wham bam thank you Ma'ma retro fit... I got the feeling that's what you got weather you ask for it are not...

The only recourse I see is a refund for the refrigerant if they missed the leak.

You owe them for the parts to retro and there time..

If it needs a condenser now it needed it then unless you somehow knocked a hole in it after you picked it up...

If I thought I missed it the refrigerant and the labor to evacuate and charge would be free with a condenser and accumulator replacement.. You would own me the labor to replace the condenser, accumulator and associated o-rings,,,may as well get'em all while we are there and take a look at the expansion tube...

While we are on the expansion tube it should have been checked at the time of the retro fit the tube tells a story... If its clean its a safe bet to move on,,, If its contaminated all bets are off...

There are plenty of folks that think they know AC but few that know how to do a professional AC repair the way it should be done and live with good service....

I have keep up with AC repairs for a long time you have to adapt and change as systems progress... Some things you buy into and some you don't, its what works for you...

You have to remember the system is 25 years old its out lived its projected life span, anything may go out at any moment. Most have never worked on a R12 system and all they have to go on is a rapid-fix in a box... I would look for someone that has keep up with retro fits as they came about there are a few tricks that can be done to make it cool as good as R12 are better in some cases...
 
I already paid him the $200. He wants $500 more for the condenser and recharge - do you think the refridgerent is free at that price?
 
When I brought it back the next day they shot dye in the system and found the leak which is what I thought they would do when they started considering the system was empty and I had no idea of its condition and told them so. To be honest I don't know what they did when they charged it the first time.
 
Would that be similar to the results I got with a shop that converted the system - only with about $150 more in my pocket?
 
Different systems but my brothers converted several AC systems on tractors (IH) from R12 to R134. Basically it consisted of adapters for the hookups and dumping in the R134 to mix with the R12. No evacuation, no changing the oil pretty much nothing. Those tractors went on to work thousands of hours with that mix in their system. I'm sure those were much heavier AC setups than the common auto/pickup has. I'm not going to try something like that here but I wonder what the deal is sometimes.
 
If they vacuumed the system before they charged it with R134 and oil (?) should it need to be filled with oil again? I'm looking at replacing the condenser and drier then possibly rent/borrow the pumo to creat a vaccum in the system (advance auto has them) and the refilling with the consumer R134 bottles.


https://www.youtube.com/watch?v=F5w3lR88fqQ
 

Copy and paste

During Component Replacement
When replacing other components of the air conditioning system, measured quantities of the specified refrigerant oil should be added to the component to make sure that the total charge in the system is correct before the system is operated.
Clean refrigerant oil should be poured directly into the replacement components as follows:
A/C evaporator core (19860): add 90 ml (3 oz).
A/C condenser core (19712): add 30 ml (1 oz).
Accumulator: drain oil from removed accumulator/drier. Add same amount plug 60 ml (2 oz) of clean refrigerant oil to new accumulator.
If any other component such as an A/C evaporator core orifice (19D990) or a hose is replaced, no additional refrigerant oil is necessary unless a hose bursts with a fully charged system. Then, the addition of refrigerant oil may be necessary with the amount to be determined by the technician. The suction accumulator-drier should also be replaced under these circumstances.


That is a general spec I would add 1 oz to the condenser and 2 oz to the accumulator... If I found the expansion tube dry I may add a extra oz... They also sell o-ring kits I would buy a kit just in case I needed a o-ring not supplied with the parts..

You can make a mess removing the expansion tube sometimes you get lucky and can pull them with needle nose pliers... It takes a special tool to remove them and sometimes that does not work... DON'T BREAK IT OFF :!: If you go after it and it does not pull out EZ just leave it be for now.
 
That's going to be my next search - tricks on how to crack it open without breaking the connections.
 

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