My compressor went bad, so I replaced & flushed everything, figuring it's all set for R134A. I had done a gasser conversion, not too horrible in the cooling department. But the results with the Diesel doesn't seem to be as good, not even close.

I live in Florida and it is headed for summer here... so my question is can you just go back to R12 after an evacuation of course, or do I need to flush it all again and drain all the pag / ester oil out? Any other thoughts about helping it cool better? It's a 93 D350 IC.

Thanks

 

Flush out the system using flushing solvent, replace the receiver/ drier, replace the oil and recharge using R-12, where are you going to get from?

R-12 and Freeze-12 are not the same.

Jim

 

I've used Freeze-12, in a 1970 Fury A/C system, worked great!!

 

Well I'm sure i can find some, it's worth the money if it's gonna keep me cool.

So the oil is NOT backwards compatible then? Now do I really want to go through the whole procedure again... if there is no other way to keep it cool enough... maybe hotshot or something? I've been thinking about an E-Fan, but being an IC truck... ugh lol

 

while 134 doesent work as well as 12 it should still be keeping you cool. i have done a couple of conversions and havent ever had a problem......as long as the rest of the system is working properly. i recently updated my truck and have no problem blowing out 45 deg air....and i live in texas where its already hit 90 this year.

 

134 should still do the truck...what other problems does your system have that is keeping it from working correctly??

We still have about 75lbs of R-12...but we are down to using less than 10lbs/year in the tractors and machinery...we leave R12 in them until it get's more expensive to change them more than once a year vs. changing them over to 134.....but we won't just blow 134 in there, we like to go through the whole system when we do.

Chris

 

It was working fine, until the compressor went poof. I placed new expansion valve, new drier, & of course compressor. I flushed everything, had it sucked down and charged with 134A it gets sorta cool while driving but like 65-70 degrees at idle and certainly no where close to my gasser which is a 93 with same component change / procedure.

 

An AC system, when it's running at it's best, is only able to reduce the outlet temp of your ducts by 40°. I don't know when you checked your outlet temps, but it was about 90° here yesterday.
At idle, you're not wicking away heat from the condensor unless your fan is coming on. Did you check that? Even if the fan is coming on, it's still not as efficient as ram air.
I'm not saying you don't have a problem, but it may not be as bad as you think.

 

Yeah it was about 85 degrees, I don't think it is a major problem, just an efficiency or lack there of kinda problem lol.

I wondering about how i can fit a fan or if there is a way to get a 134a condenser in there. or other ways to make it more efficient.

Or if it would be easier to just evvac it and replace with R12 again & if I do, do i need to drain the compressor, flush, etc

Thank you all for helping me with this btw

 

If you're going to replace with R-12, then yeah, you'll have to evac again, flush etc etc. When I converted to R-134a, I noticed a BIG difference in cooling ability, (or lack thereof. ) I can't remember exactly why '12 is better, but it is! Probably for the same reason it's bad for the environment.

I'd not thought about the condensor being different... I wonder if you could retrofit a 2nd gen condensor?

A good source for the hard parts for AC, (and radiators/IC's) down here is Cold Air Distributors. I don't know where in FL you are, but they have outlets on the East Coast, up to Melbourne or so I think. Look up their website. Very helpful and good prices!

 

My guess is the condensor in front of the rad. The R12 condensors are not made to run R134, therefore you loose a fair amount of efficiency from it. I always try to upgrade to a R134 cross flow condensor. It can be a pain to retrofit these units but the gain is worth it IMO. But then again the overall condition of your condensor could have much to do with it...how are the fins?

 

There in great shape. Still stuck on the fan thing vs R-12, leaning towards R-12.

I did however notice that my temp probe (the one attached to the line at the Expansion valve, copper tube with electrical connection) is a little loose and appears to be a bit kinked at one bend... not sure but wouldn't think this to be my problem?

 

This was several years ago, I hate the summer.



There was a chilly 28* breeze blowing inside my cab.



I installed these so my temps did not drop off when I stop in traffic.



My truck gets so cold inside that my wife and daughter always complaining, we get strange looks from people when they see us wearing a jacket inside the truck.



My truck is also so well insulated that I can open it up in the afternoon and a bottle of water on the floor is still ice cold from setting there all night.


I am running R-12 and alot of airflow

I do all my own HAVC work.

Jim

 

Have you checked to ensure that your temp blend door is closing all the way to block off the heater core?

you could also consider a coolant diverter valve before the heater core to keep hot water from circulating into the heater core when using ac.

 

A vacuum operated hot water shutoff is standard equipment as part of the A/C but if it is working or not is another question.

Your heater core is a radiator in reverse and is radiating heat into your cab unless the water is turned off.