So the center seal on my compressor gave up the ghost the other day and now I am looking at fixing everything up. The existing system was converted to R134 sometime in the past but all the parts look pretty well aged. Evaporator core is mucky, condenser core needs a good cleaning at the least, accumulator/drier is rusty, foam on suction hose is crackling, etc. I am figuring that I will replace most of the system to get everything top notch. My goal is to get really good, cold air while also improving efficiency (aka. fuel mileage) if possible.

So my question is, does anyone have any experience with this? Has anyone put a parallel flow radiator in a Bullnose? Are the newer types of compressors more efficient? Do any of those compressors bolt on like the FS-6 based ones on our trucks?

Also, my truck is a 86 F250 6.9

 

You have to know what you are doing to start messing with the A/C system. Pressures, flow rates and heat transfer rates of different coils, etc. Your system worked well stock, and well enough on r134a. I would not change it around unless you were really into A/C theory. I know just enough to usually get them working again, that's it.

 

Mine was R134a when I got it, compressor blew after a year or two. When I replaced it, I switched back to R12, and it is COLD. With a 6.9 you won't notice but a small fuel mileage difference with the stock setup (by my numbers, I lose less than 1mpg when I run my A/C, and living in Arizona, I run it pretty much 100% of the time the truck is driving from March to October).

One thing I love about the original A/C on these trucks is that, moreso than any other vehicle I've driven, the A/C only takes like 5 seconds to start blowing cold from turning it on. All of my other vehicles take more like 30 or even a minute.

A better improvement, IMHO, would be a more powerful blower motor. But that's been discussed a lot, and it seems like there's no really viable drop-in option nowadays.

 

So I am proceeding with changing the condenser out on my truck and I thought I would give a little mid-project update with some hard won technical information in case people find this thread via. google. I ended up finding a modern parallel flow condenser that was made for a 1994 F250. This condenser mounts right up in the old condenser's place, but the output (liquid line) fitting is a #6 instead of the #8 that our trucks normally use. Cutting open the old liquid line I can see that it is a #6 line with #8 fittings on both ends. I think this is a reduced thickness line because the outer diameter is pretty small. The Bullnose condenser appears to be a tube and fin or serpentine while the normal 1994 condenser I believe is a piccolo condenser.

I've ordered a beadlock crimper off amazon and am getting the the fittings to use it (the one shop I found in the area that had reducing fittings wanted $170 to make the hose which is almost as much as the tools and raw materials to make the hose myself). I am going to do a #8 female 45* o-ring fitting from the evaporator core and step down to #6 normal width hose and then do a straight #6 o-ring fitting (#6 hose to #6 fitting) to the condenser. I don't know if the total capacity of the new condenser is different so I am a little nervous about our trucks not having a high side cut off switch so I am looking into that also. With a highside cuttoff switch I might go to a #8 liquid line instead of the #6 in order to get more liquid stored in reserve for when I'm sitting at a stoplight.

In the process of doing this I am replacing almost all the AC system components with new ones. I am determined to have perfect AC with R134!

 

Hi,

if you change all the gaskets, removed all the Mineral Oil out of the system and Comressor, you can change to R134a with the new Syntetic Oil, (because R134a can not transport Mineral Oil you will have a nice yellow emulsion that can not longer lubricate the AC-Kompressor in the System if you not remove all the old oil and the syntetic Oil destroy all old Gasketsmaterial in a short Time!)
If you do all This than you can do the changing, the Colling will be 20- 30% under the R 12 Level.

In Germany we use R437A in older car AC-Systems full AC-Power and no Problems for Years.

Regards

Torsten

 

If you use ester oil in the conversion you can leave the old mineral oil in there. Proven that it works. If you want to use PAG oil, then yes, you need to clean out the whole system.

 

Well, the system was R134 when I bought the truck and I'm replacing pretty much every component in the system, so I don't think need to worry about legacy oring material or oil type. Regarding the R12 vs R134 efficiency, that is why I am putting on a larger, more efficient condenser (should be somewhere around 50% more capacity than the stock one).

 

Good Morning

Did you know witch AC-Company does this Proving and gives a Warantie about it?

Regards

Torsten

 

Here's one.

323 | R-134A Complete Recharge & Retrofit Kit - IDQ

 

Hi Dave,

ok i see there is a big diffrence between Germany and the USA no Carshop that has a AC-Expert will work like that But if you can do this in the USA fine, go for it.

I have change 5 Ford/Lincoln A6 AC-Compressors from the 70's in my Carshop in the last years after an R134a Conversion like in the Video, all Compressors was running out of lubricate. Maybe those Kits are not for sale in Germany.

Best regards

 

Yeah, very few places around here will do anything other than replace components with stuff that is a drop in replacement. Even finding someone who will crimp a beadlock hose in one of the country's major population centers (SF bay area) turned out to be extremely hard. I'm doing this condenser change myself after doing a bunch of research on how our systems shortfall in their stock design.

Everything I've read suggests that those conversion kits are not a good idea; I'd expect that the old oil will pool in places where you wouldn't want it. I wouldn't be surprised if, after one of those kits, the old oil pools up in the accumulator/drier and keeps the desiccant from doing its job. Combine that with non-barrier hoses where water migrate into the system and I'd expect the compressor to be short for this world. Also, with one of those kits, you'd still be running around with old, probably leaky orings and permeable hoses such that you have to keep recharging the system.

-David

 

I know in theory it doesn't sound the best, but in practice there are lots of these kits sold and used and they work. They have been around for years. I do evacuate the system, getting all the old r12 and air out. But I see in their instructions if the system hasn't been opened, they tell you just to pour the new in. So apparently that even works.