A/C - Need COLD system for ~$1000. Possible?
 

I've read the old threads (and used the SEARCH function all day and night), but I can't seem to find what I am looking for...

My '86 has all-stock A/C (Nippondenso compressor) that runs fine when charged, but needs a charge every year. Most recently, I put "Freeze-12" in it, and it blew really cold for about two months... then slowly got warmer and warmer... Now, I sweat as I convince myself that the outlet air is cooler than the ambient temps... :mad:

For about $1000 (or more if I have to), I want to replace as much as possible and get cold A/C. I looked into the Keuhl system ("Mr. Ice"), but it just seems so expensive for what you are getting (new lines, condensor, and some switches and mounting parts are nearly $1600). I'm thinking I can replace the hoses, drier, and compressor and fill with R-134 and get a cold system. Maybe add a fan on the condensor? Am I nuts?

I will do the install myself (as a learning experience - and I will appreciate it more if I do it myself).

Fix the leak.

You have a leak in your system and that is why you must recharge it every season. I haven't charge my system in two years.
Since the a/c is putting out cold air when you have it charge correctly, everything is working okay no need to replace the compressor, condensor or switches, etc.

Just fix the leak.

Also replace missing compressor oil and install a new receiver drier. Jim

I have swiched to Duracool on my '88 and it seems to be working but I have not made sure it's properly topped off..I have the guages but have yet to put them to work. I think you need to address what appears to be a leak and then, IMHO, the best next thing is adding an underbelly condensor (or additional condensor available from several sources). The UB condensor is less which is less than I'd been led to believe. It will require some new plumbing so don't replace hoses that will need to be replaced if you add the new condensor. I don't know if the Sanden compressors are better (I added one to my car) but I understand they are smoother running than the original.
Good luck...keep us posted.

ditto on what ruf said. Find the leak.

OK, I'm going to have an A/C shop fill it with dye and find the leak. This is my first step...

(On that note, how soon after the dye is injected do I need to hit it with a black light? Or, does the dye leave residue for a long time...?)

Hell even if you don't find the leak, just keep refilling with freeze-12 every 2 months or so. Much cheaper than your proposed upgrade.

I know.... unfortunately, my buddy who did it for my last time moved away. :confused:

Here's what I'd do:

1. Replace your original hoses with barrier hoses. Buy the hose in bulk and run it yourself. Have a local a/c shop put the ends on. There's a guy in Reseda who can reuse your old ends, thereby saving you money. Cost: $3-500.

2. Put an auxiliary condenser/fan assembly in the front left fender. Cost: Approximately $300.

3. Have the Freeze 12 flushed from your system and replaced with R-12. Cost: Approximately $250. I think Lucas Auto Air in Van Nuys can do this for you. They have a guy there that knows the 911. He did a great job evacuating and recharging my system.

4. If you want to spend another $300 or so, put a ProCooler in place of the receiver/dryer.

(The foregoing assumes you do the labor yourself, except for the flushing and recharging.)

I have an 84 with the Nippondenso compressor. I replaced the hoses, put in the condenser/fan and ProCooler, and had the system evacuated and recharged with R12. I'm getting mid-30s vent temps.

I'm in Northridge, and if you want to take a look at my set-up, send me a PM or e-mail.

Good luck!

You may now learn the disadvantages of Freeze 12; first of all it's mostly R-134a (80%) with the balance HCFC-142b. This means if your friend didn't change out the mineral oil in the compressor to POE or PAG when he installed the Freeze-12 then your compressor has likely been starved for oil as the R-134a will not carry the mineral oil back to the compressor. Further, the mineral oil gets stuck throughout the system including the condensor and evaporator impeding heat transfer and making the system perform poorly. Since Freeze-12 is a blend, one of the components will leak out more rapidly than the other, eventually eliminating any advantages over R-134a. Finally A/C shops don't like blends or other aftermarket "cocktails" as they can ruin or contaminate their very expensive refrigerant recycling machines which are usually only set up to deal with R-12 and R-134a.

If you are lucky, when the A/C shop tests your system they will not find any HCFC-142b. If they find some they may refuse to work on your system. If you can find someone to work on the system here's what I suggest (minimum cost):

Remove refrigerant.
Open hoses at low points and drain mineral oil.
Flush both condensers (do not flush evaporator).
Replace receiver/drier
Drain mineral oil from compressor and install POE (if it isn't damaged due to lack of lubrication)
Leak check system and repair leaks; replace hoses or fittings as required.
Charge properly with R-134a using gages and scale.

If you elect to spend more, install a new, better compressor; Sanden, etc., then an additional condenser and new barrier hoses.

Jim

FWIW, Lucas Auto Air also works with Freeze 12 or Duracool. I can't remember which one, but I saw a pallet of it in the shop when they were doing my car.

Jim: Do you think the Sanden is better for cooling, or just smoothness? The reason I ask is that I spoke with Hancock Industries before I re-did my system, and their view is that from a cooling standpoint, the two compressors are comparable. They did agree that the Sanden might be smoother, and rob the car of a bit less HP.

Typically the new compressors are smoother, slightly more compact and use less horsepower plus they're new (seals and moving parts not worn). Compressor capacity is usually not the issue as the systems are condenser limited. Cheers, Jim

Good advice... now, what's a POE or PAG?

My friend didn't pull anything from the system before putting the Freeze 12 in... that concerns me. :(

Why spend $250 to have the system flushed of the Freeze 12? Isn't putting R-12 back in my system a waste as it is now obsolete?

R12 is still the best coolant, though it's not manufactured anymore and is pricey. If you want the best cooling, go with R12. If you want to be more economical (and environmentally friendly) stick with the Freeze 12 or go with 134.

PAG = PolyAlkanline Glycols; POE = Polyolesters. Both are synthetic refrigeration system lubricants used because they are miscible in R-134a. Some of the "Freeze-12" type refrigerant mixes contain some POE or PAG oil but not all. If R-134 or Freeze-12 will be installed it is important to get the mineral oil flushed out and new POE or PAG oil installed. Also, the older R-12 receiver/drier desiccant bags will sometimes breakup when used with R-134a thereby dumping desiccant pellets into the refrigerant where they can clog small openings like screens or expansion valves. Jim

Remember that R12 and R134a oils do not mix. You have to get the old oil out or you will have problems. Also, you will need to change the receiver/drier. The Procooler really does help the system (I've got one) and it makes it possible to use less coolant (a bib plus since R12 is $60-70 a pound) but you won't want to go with one until you are sure you want to stay with a particular type of coolant. Too expensive to keep switching.
Someone correct me if I'm wrong but...I've been told that R12 oil basically seals the hoses so there is no need for barrier hose. If you have hose leaks with R12 its because they are old and cracked. To start with, change all your O-rings (theres a bunch of them) and use a oil/dye mix to find the leak. My leak was at the evaporator.

Because I have a mixture of R12 and Freeze-12 (R-134 blend) in mine... will a shop have issues with putting the dye in my system? Will it contaminate their machine, or do they just pump it in?

I've heard, though don't know personally, that the only reason this might be true is that in older cars there's more "gunk" in the system. I wouldn't want to rely on "gunk" to keep my expensive R12 from leaking. If you're going to do the job and use R12, change out the hoses!

I think they just pump it in, so this shouldn't be a problem. Jim, your thoughts?

I feel your pain, I am going through the upgrade now. I pulled the old hoses out this weekend. Next I am going to our local hose guy, he will recycle my fittings and make me new barrier hoses for small dollars, less than $200. ACKTs will do yours for reasonable dollars if you send them the old ones.

For your leak, you may want to do a look at your your hoses. I could easily tell where my leaks were, the black hose was oily from the mineral oil in places where Pcar's don't leak oil. Fittings are a logical starting point. You can easily check by putting the car on jack stands and feel where the vertical hose runs go horizontal. The first place to check are the fittings that get the most work, you stress them everytime you lift the engine compartment lid.

For the classic undercondensing of Pcar's, I found a 3 pass 12x12 condenser for $20, added a 1000 scfm fan and will put it where the washer bottle was in the front drivers wheel well, perfect fit and can use the existing mounting from the bottle. Minimum cost for new hose. I also found a new Seltec compresser on eBay to take the Nippondenso's place for $99. Not a perfect match on mounting but workable. The Seltec is the same as a Sanden but not as much noise at 1500 rpm plus less HP loss and over all smoother, plus it reaches max efficency at 3000 rpm vs 6000. I flushed the condensers with 100% mineral spirits per ACKIT's web page instructions. My next struggle is to pressure test the condenser and evaporator, I don't want to pay the local ac shop the $30 they want per condenser (I have 3 now remember) so I am looking for a solution. Any thoughts from others appreciated.

Since mineral oil is not miscible with R-134a it tended to stay in place on the old non-barrier hoses after conversions were done to R-134a. This effect significantly slowed down the permeation of R-134a through the older type hoses and allows them to be used in conversions. The mineral oil is not a solution to old, cracked hose nor will it help leaks at fittings or joints.

If an A/C shop injects dye and finds the leak then what? Some leaks may be fixed by tightening a fitting but not all are solved this way. To effect repairs the refrigerant will likely have to be removed from the system; is the shop willing and able to handle an R-12, R-134a and R-142b mix and dispose of it? They can't just vent it (big fine if caught) - you and your car could be a plant from the EPA or CARB. You need to check with the shop and see what they can do. Your buddy didn't do you a favor putting Freeze-12 in your system.

Examples like the above will likely result in the eventual ban of sales of refigerant to DIY's. There is now apparently too much R-134a being released and it is being attributed to DIY's venting systems and partially used cans of R-134a. Sigh. Jim

ACKT = ? :confused:

My plan of attack...

I'm going to get the dye done so I can check for leaks.

If there are one or two small leaks, then I will repair myself (hoses, o-rings, fittings, etc..) and have more Freeze-12 put in for a temporary fix for the next couple years (at a shop that deals with the stuff).

If I have too many leaks or really old lines (the PO replaced many lines over the years), I will remove the old hoses and replace with new hoses. Then, I will have the entire system flushed and filled with R-134. I'll add a fan to a new condenser in the LF fender and make sure the compressor works.

Oh, in both cases I will replace the drier.