I know for many of you it's not quite time to talk about "air conditioning" in the Aero. Well, we southern folks need to start thinking about it soon. I've got a couple questions...

1. Can I convert easily to 134A? My A/C accumulator/dryer parts are old and clogged and I will have to start disassembling the system anyway to get it working again. Any advice on the process?

2. My Aero has the AUX (Rear) A/C. The rear air seems to have filters and expensive parts that I'm not sure I really need if the front A/C works for me. When I looked at RockAuto.Com for accumulator parts, I had got the idea to just replace the A/C Accumulator with the front A/C only. I am sure that is just the beginning of my "conversion" that would eliminate the rear A/C. The accumulator is just half of the system to get cold to the rear A/C. What is the other half? Also, I am sure the quantity of 134A will also have to be adjusted?

Thanks for the suggestions...

Michael
'93 Aero 3.0L
'93 Aero 4.0L

 

I overhauled my system last year after converting to 134 the year before.

Now looking back on it, I should have done both at the same time. The 134 conversion was straight forward. Get rid of the Freon, add the 134 conditioner that came with the kit, draw a vacuum and then refill with R134. Good cold air after, although my airflow in front was not the best.
During the overhaul I replaced the accumulator, all Orings, orifice tubes (they are different for front and back) and the rear high pressure hose with filter (the filter was plugged up). I was also able to score a brand new compressor for next to nothing, so that went in also.

The thing I would highly recommend is to take the housing of the evaporator core off, remove the core and thoroughly clean it. You'll be surprised at the difference. I would be hard pressed to give up that rear A/C.......the front alone just doesn't do the job on my extended 91.

Klaus Cook
Houston, TX

 

The problem with a straight swap to R-134a is that it does not carry the mineral oil properly. If the system is to the proper pressure it will work well, but if you loose some of the pressure, the compressor will suffer oil starvation eventually. This may not happen within the vehicles remaining lifespan, but you do run an increased risk. The proper method is to drain the old oil and replace the oil with an oil that is approved for R-134a. You don't have to get all the old mineral oil out, just the majority of it. Then you are set. Since you conversion has worked well for you, don't mess with it other than keeping the system topped off.

 

Last time I researched it, the R134a conversion was "not recommended" for dual-A/C Aeros, unless the condensor was updated. It has been a couple of years since I read that though.

This was from one of our R134a conversion "kit" suppliers.

Personally, I recharge with R-12. The add'l cost is not that great if your system doesn't leak much. I long ago added the aftermarket plastic clamp-on joint stabilizers.

 

keep the rear A/C...with all the Aero glass it's a godsend on those 100d F plus days....even use mine here in Pac. NW and trips to the desert

change the condenser to this high efficiency R134a rated cross flow model
condenser can not be effectively flushed of all old R12 and contaminated oil
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Co de=Parallel

remove and drain the compressor
remove and flush all hoses
replace accumulator, all o-rings, rear filter and orfices
vacuum evacuate the system and vacuum test
fill with proper oil PAG46 and charge with R134a, R12 is becoming too difficult to find especially on vacation in the outback
can buy R134a anywhere and even care can on long trips if you have a slow leaker

flushing
http://www.aircondition.com/tech/questions/25/

http://www.id-usa.com/how_to_retrofit.asp

http://www.autoacforum.com/categories.cfm?catid=20

conversion parts
http://www.ackits.com/merchant.mvc?S...onversionitems

use refrigerant rated thread sealer on connections
http://store.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Co de=Ford94Aerostar3-0

my 96 came orig. w R134a...i just flush and change accumulator, oil plus orfices every 3>4 years...will run us out of van on 100d day

 

Nonsense I love A/C questions even though I just froze my butt off in 18 degree temps yesterday .

First I would recommend you flush the system. The condenser for the Aero I believe is a type with very narrow passageways and must be replaced rather then flushed since flushing solutions will just plug it up. Also R12 condensers won't work too well with R134 if you could use it anyways. The hoses can be flushed however you must do something special first.

I definately agree that you should check your evaporator I replaced mine last year since the brazing between the tubes corroded and caused a leak. It was so bad that I could smell the dye from the vents inside. The thing was so plugged up when I first turned on the A/C there was so much more air blowing through the vents it felt like a hurricane . If the evap is fine flush it.

Those (filters) on the high side hoses aren't filters they're mufflers and they are the reason why you can't flush these hoses without modification. If you wish to flush these hoses you must remove the mufflers during the flushing process because sediment pushed out of the hose and not to mention the flushing solution (and mineral oil) gets trapped in them and causes all kinds of trouble later. After the flushing replace them with new ones.

You must also replace ALL of the O-Rings with the R134a approved type. They are green in color and can be picked up at the dealer or any auto parts store.

If all goes well and everything is flushed then you pour new PAG-46 oil into all the parts (quantity on sticker on top of blower). I believe it was 6 oz for my Front A/C only Aero (1 in condenser) (3 in evaporator) and (2 in compressor) turn the compressor clutch plate with your hand about 4 turns to prevent it from being hydro locked. Please note that its not an option to flush if you are converting to 134a because mineral oil (R12) and PAG oil (134a) DO NOT mix.

Also be aware you need to vacuum the system out before adding R134. I did this myself because I have the pump and the manifold gauges to monitor the system pressures. However there are plenty of places willing to do this for you however if you want to use that R12 conversion junk rather then convert properly (IMO) then they will just vacuum the system and you will be on your own to charge the system.

 

Krankshaft, thanks for the encouragement and technical feedback. I've got a couple more questions...

You indicated it would be best to move to the 134a condenser to take better advantage of the conversion from R12. As I looked through the RockAuto catalogue, it seems the R12 to 134a conversion began with the '96 model year. If I want to use the 134a condenser as you suggested, I must consider connnector compatibility with the remaining components. The 134a condenser has a different connection (Block/half-inch P-Nut female couplings) than the R12 condenser (#8 & #6 Male Quick Connect). Fortunately, RockAuto shows the same compressor for both R12 and 134a. So, I'll try to replace it as a last resort. I'm guessing since both R12 and 134a use the same compressor, those hose-to-compressor connections are the same regardless of condenser?

Since I will probably replace many of the components of the total A/C system (hoses, o-rings, driers, filters, etc.) will I encounter other compatibility issues if I go to a 134A condenser?

Thanks for your advice...

 

Michael:

My '95 with dual A/C comes with R134a, and the condenser connections look identical to the ones on my '93, which had R-12.

Perhaps Ford changed the connections in '96?????

 

Just get a conversion kit from AZ......6 bucks it contains the high and low side aluminum fittings that screw on over the original ones.

I also forgot to mention in my previous post. I also replaced the pressure control switch that screws into the accumulator. The 134a apparantly runs at a different pressure than Freon and requires a switch set to a different pressure.

Klaus Cook
Houston, Texas

 

My 96 3.0 front A/C only with the factory R134a condenser has 2 P type nut connectors the top one is the high pressure gas from the compressor and the bottom one is the high pressure liquid that leads to the evaporator inlet orifice.

Hopefully your current system should have the same connections.

Don't get me wrong a proper conversion to R134a is costly and if you are just looking to get cold air without spending much money use the conversion stuff. Just be sure to screw on the conversion fittings on the original R12 fittings so that anyone working on the system knows that there is no R12 in there anymore also don't forget the retrofit sticker.

Those "conversion" refrigerants are just mixes of base refrigerants. For example Freeze12 is 20% HCFC142b and 80% R134a. Other problems with these mixtures are how well they mix with each other when they leak if they don't mix well the proportions can get messed up very quickly. Most of them are engineered to be "topped off" a few times without it badly affecting the system performance.

For example lets say you have a slow leak and you top it off a few times your not topping off the exact proportions of refrigerant that was lost (i.e. 142b and 134a) your just adding more of the mixture which doesn't fix the proportion inbalance eventaully the inbalance will affect the systems performance.

Also before a retrofit refrigerant is installed you must have the R12 removed first. If you still have some in the system there are plenty of people willing to take it off your hands since its so scarce .

Just FYI.