Crossposted from the HVAC section.... hoping you guys might have some first hand on this one.....


A/C started losing performance at the end of last summer. Along with a long list I decided to check it before this summer....

After the temp got to about 95 I decided to check the low pressure side. I bypassed the pressure switch, and the compressor is locked solid. The new compressor warranty is only valid if the accumulator drier and orifice tube are replaced, so I'm doing all three.

I've seen and been advised that using a flush cleaner and blowing out all lines with compressed air is a smart move, so I will do so. I didn't really consider if the condenser could be cleaned easily, but will look at that as well. Does anyone have any other suggested work be done at the same time, or is the current course a safe bet. If it involves more time and $$$ to do it right I'd rather take that route.

The only specific question I have for now is on the fixed orifice tube. I assume (and I say that with risk) that the line coming from the evaporator is fixed, and the orifice tube is the external part only.




Another concern I have is having heard that underdrive pulleys and A/C compressors do not like each other, and using the pulleys can reduce compressor life. I had UDs on for three years before I had any problems, and it doesn't make sense to me, but I'd like to hear any expert opinions on this...... (the peanut gallery opinions are already covered )


TIA for any help.

 

I would think you would be fine with underdrive pullies. They will turn your compressor a little slower, but I dont see what that would hurt. I really doubt you will be able to tell difference in the cooling. Your orifice tube is inside the metal line that runs from your condensor to your evaporator. I am not sure what year or engine size you have, but most of them are in the part of the line that runs vertical (just before the evaporator). Have fun- they can be a PITA to get out.

 

I would also install a in-line filter in the liquid line before the orifice tube. No mater how much you flush the system, there will still be some contaminates left from the failed compressor. this filter will prevent the orifice tube from plugging, causing the new compressor to fail.

 

A/C? That's the thing that makes the air cold, right?

Sorry boss, I can rebuild an engine in my sleep, but I don't know diddly squat about the A/C.

Just didn't want you to think I was ignoring you.

Take care,
~Chris

 

Chris,

If I had the option, I'd pay the money to just change the climate to California low humidity conditions. Out here when we get 95 degrees it's usually with 80-100% humidity.


Tailgator,

Good idea on the filter. I don't want to trash any of the new stuff.



FORD302GUY,

I assumed it was just an urban myth, but thought I would throw it out just in case any A/C experts had any input.

 

are you going to be putting in R134a? My AC system is going to be needing some work sometime soon, its almost 14 years old. how much of a difference will converting from R12 make?

 

Dave186,

My '95 already has the R134A factory installed. I don't know the details, but the kits to convert are fairly cheap, so if you do them in combo with maintenance or replacement work my guess is that it would be fairly simple.

 

I converted my Tbird to R134a, and the performance never was on par with the R12. I wonder if there is anything different between the trucks with factory R134 (like your 95) and mine with the R12, maybe a larger condensor? my boss has a 95 as well with the factory R134 and his works just as good, if not a bit better than my R12. Im really avoiding switching untill i absolutely have too. Right now I think my system is just a little bit low and just need topped off, as it still works awesome, just needs some maintenance. There is an ad in my local paper that says "replacement" R12 refrigerant, im gonna call tommorow and see what the guy is selling.

I found a couple refrigerants on the web that are compatible with R12, but im not really sure about them yet. http://www.autofrost.com

 

Dave,

If converting lessened performance on one, I'd say you're smart to take the route you're on.

Locally the small cans of R12 are still readily available. It's a little more expensive and always comes in the smaller cans, but even the chain stores (and K-Mart) have it on the shelves.

 

you can buy R12 off of a shelf? i thought you had to have an EPA licence to handle the stuff. Around here you can buy R134 almost anywhere, but ive never seen any R12.

 

Since '92 you have to be a certified A/C Tech (licenced) to be able to buy any R-12 legally. Since they quit manufacturing it in'96 (in this country anyways) R-12 is extremely hard to get of late.