Looking to finally tackle the lack of AC in my '95 SC2. Hasn't worked without a leak in over 15 years. I know the lines are probably corroded internally, but at this point it doesn't need to be perfect, just cooler so I can drive it in the summer.

Last time I charged it about 5 years ago, it held a full charge initially; at something like 235 over 40 but only for a month.

I'd like an affordable refrigerant sniffer to find the leak (,s) in the system so that I may decide whether or not it is worth the time and effort and cost to repair it..

Any suggestions? Needs to be compatible with the newer refrigerant HFO-1234yf so it does not become a one refrigerant tool collecting dust.

I really don't want to throw parts at my AC system. Pretty sure the original 29-year-old compressor is in need of replacement. It sounds awful and has for years. It hasn't imploded and sprayed metal everywhere as it's still compresses.

Want to avoid going after the evaporator if it turns out something else is at fault. Dude, I am not slamming you. You put it a lot of work based on the diagnostic you did at the time and I have nothing but respect for the amount of effort you put in.

Thanks

 

Fixing an AC leak is the next thing I need to do. I've been looking around at leak detectors, and I think I my plan is to grab one of the Harbor Freight Icon 59375 units off eBay. They do R1234yf et al. I don't know if you're as "value oriented" as I am, but that seems like the cheapest way to get a leak detector that works "fine".

I mean, I'll probably start by just pulling a vacuum on the system and listening for hisses with a pipe up to my ear before I buy anything. But you've probably gone that far already.

 

The better way is to put some pure, dry Nitrogen pressure or Argon is another Nobel (non reactive) gas that is regularly available to folks that weld.
Pressurize to 300 psi and use soap bubble water at all the joints.

Derf, you say the pipes may be internally corroded and that may be true, especially if done DIY by someone who hasn't learned the basics (I know because I did it once)... and if that is the case, all the evaporator will need replaced.
If the compressor is working then it is working.
R134a if it is not properly evacuated, it will become acidic inside the system.

AutoZone loans vacuum pumps to evacuate the system before charging.
Be careful of all the walmart "with stop leak" "with oil charge" because that oil /stop leak in an oil carrier" is NOT refrigerant and will occupy the space in the system that is (was) used by active magic fairy juice

Also. the biggest thing I see is folks not purging their hoses BEFORE connecting to the vehicle. Right from the start, they shoot a hose full of air into their system... give a little blast of refrigerant to clear the hose.

The low side of the refrigerant is the cold temperature. Another thing often done by the uninitiated is over filling the system. When using the spray can chargers with the valve and gauge. You want to shoot for the low side of the green range not the high side of that arc.

 

My AC system is 100% original from the factory and 30 years old. The seven or eight times I've refilled it, I've done it with a gauge set but did not evacuate the system beforehand as I did not and still do not have a vacuum pump. The vehicle has said idle for multiple groups of years in its past. Thus the system has been essentially empty - any residual refrigerant for quite a long time over the years.If I get the rest of it fixed up, I'd sooner repaint it then fix the AC, though I'd obviously like to do both.

 

There is also a flushing or rinsing technique though no longer practiced under the EPA and that was where you would purge the air out of the lines with refrigerant...

BUT, like I said, if you have an AutoZone, their "Loan-A-Tool" program is amazing they have vacuum pump (though when I use it I end up doing a vacuum pump oil change as they don't maintain them like I would (do).
I think they hold $187 on a credit card while you borrow it up to 90 days (which is crazy) I've even had them hand me cash because it is late for them to credit it back to the card.

R134a becomes highly corrosive to aluminum in the presence of moisture.
My best practice is to pull a vacuum on the system, then break the vacuum with dry nitrogen gas (or argon from my welder) then pull the vacuum again.

*many times in the forums someone 'thinks' they know and will tell you that you hold the system under vacuum as a leak check... Well, that is half true. If your vacuum doesn't ho;ld you MAYBE have a leak OR you may have saturated refrigerant still in the oil or moisture in the system. If you vacuum deteriorates, don't just assume you have a leak and start changing and replacing OR give up... continue to run the vacuum pump and then repeat the test.

On some industrial freezer systems, they run the vacuum pump for days while pulling a deep vacuum, all the while breaking the vacuum with dry nitrogen to scour all air and moisture out.

R1234YF is a mixture of butane and propane and only has a GWP (global warming potential) of 4 where CO2 is GWP of 1 and R134a is 1430 (1,430 times more potential to reflect the solar 'heat' bounce back off the atmosphere than pure CO2, rather than radiate off into space)

 

Come on dear boy Have a cigar
You're going to go far

 

Yeah, me and machines, we usually go well together... me and people, sometimes not so good
People are the inconsistency in my life...
Anything worth doing is worth doing twice... (Wilbur V RIP 2017)
Nothing is impossible for the man who doesn't have to do it... (Wilbur V, again)
I can disassemble a transmission and put it back together again, as long as some 'person' doesn't touch, take, move, clean up, or help...

Oh, btw, the new 'sniffers' don't work nearly as well with these new refrigerants as they used to work great with R-12 / R-22
(there is even a technique where you evacuate a system, put R12 or R22 in (partial) then pressurize with Nitrogen to use the testers)

The NEW and BEST testers today are sonic and they listen for the 'hiss' of leaking gas
Also, the fluorescent dye and UV light with yellow glasses works pretty good, (just don't keep putting ounce after ounce of UV oil dye in, taking up the space designed for active refrigerant)