Dezag

Hey guys, I'm new here but I need some help. I'm not the biggest car guy but I really love this car. I inherited from my dad, who got it from my grandparents. It's a 92 LS400. My issue is that I have a pretty big leak in my R12 A/C system. How can I find the leak in an old R12 system. I can only find leak detection systems for an 134a system. I'm undecided if I want to convert it or not. But either way I need to find the leak first. Any tips or info that you could provide would be very appreciated.

sha4000

iTrader: (1)

I think your best bet is to take it to an A/C shop and they would be able to tell you where the leak is with no problem. I highly doubt that you would be able to find it or fix it reliably on your own.

timmy0tool

iTrader: (7)

R12 is already phased out and you will need to take it in to a shop that specializes in A/C to convert it reliably to R134. They should be able to find the leak as well.

PureDrifter

iTrader: (10)

+1 for an A/C shop if for nothing else than to diagnose the leak.

sam12345

iTrader: (1)

My 92 is converted and is very cold, my compressor whines a little but it has been doing it for 3 years and still works. On my 92 miata I used freeze twelve, no conversion necessary, works great.

http://freeze12.net/

http://www.amazon.com/Freeze-12-Refr.../dp/B002EQKP2Q

http://autorefrigerants.com/co00031.htm

johnnyg66

I second freeze 12. Have that in my ls for past two years. No issues and gets cold.

Dezag

I'll look into seeing how much they'll charge me to find the leak, but I'm on an EXTREMELY tight budget. I've actually done a lot of learning about cars for this car. Changed and fixed my brakes. Fixed a frame dent with a chain and big tree in my yard(lol especially proud of that one). Changed my alternator and fixed the power steering aspiration problem. And a few other things. But all on the cheap. Junk yards and lots of internet searching LOL. Thanks for the responses y'all. If anyone else has some wisdom to impart on me I'm all ears.

sha4000

iTrader: (1)

Is the A/C blowing out hot air? Congrats on all the stuff that you have been able to do, I'm a DIY guy also The thing about the A/C system is that you really need special equipment that they only really have in a shop to pressurize the system to figure out where the leak is at. The most you could do is add freon if you could even find some R12 but it will eventually leak out again. It could be worn out rings or a compressor or something else being that it is so old. Sorry for the bad news.

LScowboyLS

Here are a few things to keep in mind that I will pass on as a 20 year A/C technician:


1. the same leak detection systems that will find R-134a leaks will also find R-12 leaks

2. The two main leak detection systems used in professional ships are fluorescent dye and the Yokogawa halogen leak detectors.

3. R-134a systems are less efficient than R-12 systems, what this means is that if you simply tried to flush a system and replace the refrigerant and started running R-134a in place of R-12, you will lose cooling capacity, in order to bring the efficiency of R-134a up to R-12 levels, you must replace the condenser with a high efficiency model.

4. because of reason #3 above, it is much cheaper to locate and fix the leak and refill with R-12, than it would be to purchase a new condenser in order to do a a proper R-134a conversion

5. to locate a refrigerant leak on the cheap, you can first just visually inspect the system, R-12 is mixed with a mineral oil to lubricate the compressor and this mixture flows throughout the system, so most leaks that can be spotted under the hood (pretty much every kind other than a leak in the evaporator) will have a corresponding oil leak along with the refrigerant, so say one of the rubber system refrigerant hoses has a big grease spot on one end, that is a likely candidate to be your leak area.

6. all but the smallest refrigerant leaks can be found with soapy water and looking for bubbles, this is how we found A/C leaks back in the day, before electronic leak detection systems.

YoshiMan

Thanks for the Freeze-12 link.. i'm going to look into that for my old 75' Cadillac...

But to add to the thread, R-12 is horrendously expensive, as since it is no longer manufactured, as far as i know, the only source of it is from discharging older A/C systems.

I had an 87' Toyota Cressida for several years that had a totally empty A/C system when i bought it... rather than changing it over to R-134A, i had a shop recharge it with R-12 at the tune of $200, only to find out that the compressor would run for 3 seconds before popping the circuit breaker. Some time later after the electrical problem was rectified, I took it back and got smacked with another $200 R-12 charge since it had apparently leaked out in between even though they had tested for leaks.... grrr.. R-134A, (and this Freeze-12 stuff from the look of it) will run quite bit less than that, and i would of gone another route had i known that the issue was going to go that way... just my 2 cents.

PureDrifter

iTrader: (10)

R12 is illegal for use in automobiles, hence the price. the shop's doing something illegal.

LScowboyLS

This is incorrect information. The shop is doing nothing illegal whatsoever in his example.

As long as the vehicle originally was built with R-12, (like the 87 Cressida) then it is legal to charge it with R-12. (and always will be) This is why professional shops can still legally buy R-12, however it is illegal to manufacture any new R-12 (in this country) and has been since the mid-90's

R-12 is still manufactured new in other countries, and A/C professionals can still obtain it legally, with restrictions on its use. The high price is due to the availability of R-12, however, sometimes the availability of R-134a isn't so great either and the price can spike up to nearly the same level as R-12

billydpowe

iTrader: (1)

putting the dye in your system will show the leak, after repairing it you "should" evacuate it and then recharge it. I have seen it done without evacuating, but I would not recommend it... but freeze 12 is fine for any system and will mix with anything on the market at this time. cheers, and good luck. are you in Dallas? HERE IS A LITTLE INFO FOR YOU:
Thinking about using Freeze-12 refrigerant?

You may be surprised to learn that it is nothing more than a blend of R134a and HCFC 142.

Most of the "alternative" refrigerants are really nothing more than a slightly different blend with a fancy can. If you are unlucky, you actually get propane, butane, or some other flammable gas.

ALTERNATIVE REFRIGERANT BLENDS

Free Zone (RB-276). Supplied by Refrigerant Gases, this blend contains 79% R-134a, 19% HCFC-142b and 2% lubricant.
Freeze 12. Supplied by Technical Chemical, this blend contains 80% R-134a and 20% HCFC-142b.
FRIGC (FR-12). Made by Intermagnetics General and marketed by Pennzoil, this blend contains 59% R-134a, 39% HCFC-124 and 2% butane.
GHG-X4 (Autofrost & McCool Chill-It). This blend is supplied by Peoples Welding Supply and contains 51% R-22, 28.5% HCFC-124, 16.5% HCFC-142b and 4% isobutane (R-600a).
GHG-HP. Also supplied by Peoples Welding Supply, this blend contains 65% R-22, 31% HCFC-142b and 4% isobutane (R-600a).
Hot Shot\Kar Kool. Supplied by ICOR, this blend contains 50% R-22, 39% HCFC-124, 9.5% HCFC-142b and 1.5% isobutane (R-600a).
The suppliers of the alternative blends say their products typically cool better than straight R-134a in systems designed for R-12, and do not require changing the compressor oil or desiccant in some cases. Changing the desiccant to XH-7 is usually recommended if an R-12 system is converted to R-134a. The desiccant should also be replaced if a blend contains R-22 because R-22 is not compatible with XH-5 or XH-7 desiccant. The recommended desiccant in this case would be XH-9.

The suppliers of the alternative blends also insist the fractionation problem is exaggerated and do not foresee any major problems with recovering and recycling their products (recycling blends is currently illegal, but the EPA is reviewing its feasibility).

LScowboyLS

NEVER charge a repaired (opened up) system without first drawing a hard vacuum, it is a recipe for disaster, not only will it not cool well, but the humidity in the air mixes with the Fluorine and/or Chlorine in the refrigerant, forming hydrofluoric and/or hydrochloric acid, eating up your A/C system from the inside!

billydpowe

iTrader: (1)

I am aware of a few times when a vac pump was not handy and they purged the system with freon, shutting the valves down and bringing it up to level for cooling. and it worked. how long?? dont know, but it did work.... and yes, I taught AC training at the GM Training center in the early '60's. so I know what SHOULD be done, but I have seen "other things" work....
while in Korea in the 50's, I have pissed in the master cylinder so it would have brakes on my jeep. not normal, but Korea was not normal either. that worked too..