Automotive Air Conditioning Information Forum (Archives)

mrau92me on Fri June 07, 2013 1:09 PM

Year: 1994
Make: Mazda
Model: B3000
Engine Size: 3.0L V6
Refrigerant Type: R12
Country of Origin: United States

I'm in humid Alabama. Truck has over 190k miles on it. I drive it to work about 35 miles and around town some.

What would you do if it were your truck? What parts would you replace and/or just flush? I want to do it myself. I have converted my '87 Mustang before.

Thanks.

Dougflas on Fri June 07, 2013 2:31 PM

If it were mine, I would stay with R12....but I have over 100lbs of R12. Those small systems needed R12's performance to work properly. You will need to change the condenser for R134a and probably the tXV also.

94RX-7 on Sat June 08, 2013 10:01 AM

You sure it is R-12? My sister had a 1994 Ford Ranger (basically the same truck) and it was factory R-134a. Maybe it was a mid-year change?

I would flush the evaporator, and replace everything else. You could flush and re-use any lines that don't have inline mufflers/filters, but I'd be inclined to replace rubber hoses that are nearly 20 years old if it is a long term keeper.

Cussboy on Sat June 08, 2013 3:03 PM

Quote
Originally posted by: 94RX-7
You sure it is R-12? My sister had a 1994 Ford Ranger (basically the same truck) and it was factory R-134a. Maybe it was a mid-year change?


I'm also thinkin' that his 1994 may also be factory R134a, and yes, it's a ford Ranger. 1993 and earlier Mazda trucks were made in Japan, and had R-12 AC. There should be a sticker under the hood detailing the AC capacity and refrigerant, or he could post a photo of the service caps, or the valves after the service caps are removed.


Edited: Sat June 08, 2013 at 3:03 PM by Cussboy

mrau92me on Mon June 10, 2013 12:50 PM

Yes, my '94 B3000 is essentially a Ranger...first year that the Mazda truck was built in a Ford plant. Quite sure the under-hood sticker says R12 (but I have to say y'all are making me doubt myself a little bit).

I'm on the fence about switching to R134a because I have access to a DIY shop here at the base that can charge R12 at very reasonable pricing. Because of compressor failure, I was expecting to replace the accumulator and the orifice tube (but with which tube?). However, I was not expecting a condenser replacement to be necessary. Please explain why some of you say I must replace the condenser if I change to R134a. Are you saying I'll need to get a condenser of a different design from the old one?

Even if I stay with R12, will I not have to flush the old condenser and the other remaining components anyway, since the compressor failed? I had a mechanic at the DIY shop tell me that I didn't need to flush the system if I stay with R12.

I guess I'm looking to know: As a result of compressor failure, what needs to be replaced if I go R134 and what needs to be replaced if I stay R12, so I can compare. Note: I currently don't have any flushing devices.

Cussboy on Mon June 10, 2013 2:24 PM

From Wiki (for whatever that's worth):
"The Mazda B-Series became a re-badged Ranger for the 1994 model year. While 1993 Rangers used R-12 Freon, 1994 saw the transition to CFC-free air-conditioning systems in compliance with the Clean Air Act."

mrau92me on Mon June 10, 2013 3:04 PM

Quote
Originally posted by: Cussboy
From Wiki (for whatever that's worth):

"The Mazda B-Series became a re-badged Ranger for the 1994 model year. While 1993 Rangers used R-12 Freon, 1994 saw the transition to CFC-free air-conditioning systems in compliance with the Clean Air Act."

Hmmm...the wording "1994 saw the transition" could mean that the transition occurred during that model year, so it could still mean I have an R-12 system. I currently have my '96 Dodge Ram with me because it has air, but I'm going to confirm R-12 when I get home.

mrau92me on Mon June 10, 2013 7:06 PM

So, does the condenser need to be changed or not in either case, staying with R12 or switching to R134a? Thanks everyone for all the replies so far. Good chance I'll stay with R12 if the necessity of changing the condenser only applies to R134a.

mk378 on Mon June 10, 2013 8:52 PM

What went wrong with the old compressor? If it suffered internal failure / seize up, there are going to be bits of metal in the condenser. If it only has a leak or a clutch problem, you might get by with just slapping a new compressor on.

mrau92me on Tue June 11, 2013 10:28 AM

I confirmed that it is an R-12 system via a manufacturer's sticker on the evaporator/heater core cover. It says 0.79 kg of R-12 on the sticker.



Edited: Tue June 11, 2013 at 10:37 AM by mrau92me

mrau92me on Tue June 11, 2013 10:37 AM

Before I bought the truck at 85k miles (2002 I think), I took it to Mazda to have it checked out. The only thing the mechanic told me was that the compressor had a growl, saying I’d be lucky to get a year out of it. Fast forward 10 years later…I was outside looking at a car for my daughter with the wifey waiting in the truck with ac running (compressor still growling) when I heard a loud noise come from that direction. When I got back to the truck, the ac wasn’t cooling.

Compressor & clutch still turn, but there’s evidence of leakage at the back of the compressor near the suction & discharge line connection (looks like weld spatter to me). I don't know for sure if the "weld spatter" was there before the noise. Could the loud noise have been a seal blowing? The system had had a slow leak for about a year or so until that point (I was topping it off with Freeze12 because I could get it from a "mom 'n pop" store). Or, could the loud noise have been the compressor failing internally but it's still able to spin?