92 Q45 - AC wouldn't take a charge

[tkd_q45]

Tried having my AC re-charged over the weekend. It was possible to "unload" the coolant but there was a problem when it came time to "reload" - any thoughts?

[Q451990]

Remember that your compressor is protected by a dual pressure switch located on the receiver drier. It will drop out (open a switch) when the system pressure is either too high or too low. I had the same problem on my truck when I was ready to recharge her with 134a.

I just jumped out the compressor relay and that got everything moving and allowed me to take in enough refrigerant to build up some pressure. I would assume that some professional systems put enough pressure on the recharge refrigerant to avoid this step - but I was working with 134a in small cans from Wal-Mart... not the best approach, but then again it's the truck, not the Q, and everything is working great so far!

Heath

[DAEDALUS]

The compressor was cutting off, but it was because the pressure was too high, so jumping it woudn't be a good thing in this case.

It was almost like there was air in the system, but I had it vacuumed out to 30" Hg. It's possible my equipment is faulty (letting the air in), but I just used it 3 weeks ago on my car, and it worked fine. I ran a purity check on both the car and the source and both checked out 100%. Blockage in the system is my other guess, but I haven't yet heard of that on a Q.

[Q45tech]

The Q AC system is no different than any other variable displacement system of that era.........same parts.

The compressor / engine is not running when you recharge the R12....it is done by weight [1.1 Kg]

[tkd_q45]

Has anyone heard of this product?

Freezone RB-276_http://www.heco.net/freezone.html

Also does anyone have any refferals to AC shops in Los Angeles? Just called Lucas AC in Van Nuys and they are booked till Aug 4th. Is this something I can trust to a more "basic" mechanic/shop IE Pepboys?

[Q451990]

I'd be skeptical of both the "freezone" and PepBoys. Do some checking around for A/C forums on the internet and see the horror stories on conversions. If Jerry Tucker http://www.jerrytucker.net does A/C work, I'd consider the 120 mile drive. I drive farther than that to get to T3 for someone with Q experience!

Heath

[DAEDALUS]

One problem with any "non-standard" AC conversion is that you will have a much harder time to find someone to do any future work on the system. It is illegal to vent the refrigerants, so the shop doing the work would have to have a dedicated machine solely for recovering "hodgepodge" gases, which will never get recycled. R-12 and R-134a are the only gases common enough to almost guarantee available service. Even R-12 service is being phased out, starting with the smaller mom-n-pop shops. The equipment costs the same, so it doesn't make sense for these places to buy the one that gives 1/10 the income of the other, especially if they have enough work on their plate.

[Q45tech]

I can't imagine a Q owner worrying about the price of R12 vs R134a.............the difference is less than $100 at the most expensive [even California] shops. In Atlanta we are buying all we want at $650 per 30 lb container....due to loses in system you can recharge 11Q and most have some residual R12. We only charge for what we use........the tech subtracts the residual from the full charge bill............not a common practice from what I hear.

But then again in 13 years I probably have used less than 2 NEW pounds on my Q.

If you maintain your AC and catch problems before they become expensive problems the costs are nominal.

I have an inexpensive [RadioShack] inside/outside electronic thermometer .........with a 15 foot cord ..........so useful in monitoring underhood, intake air, or AC.

Buying used cars is always a risk since they may just recharge the system to prove cold air if the leaks are slow.

[DAEDALUS]

The cheapest retail R-12 I found around L.A. (quick search) charges $3/oz. 30lb containers cost $1000 locally. While I certainly agree with the ethic of only charging for R-12 added/required, not a single shop I've inquired with agrees. Thus there is likely to be over $100 difference in service from one gas to the other in L.A. Still much cheaper and less risky than a conversion though.

[Q45tech]

Saw some old 12oz R12 containers on ebay go for $15-$20.....Need to move my private stock to LA I just sold a container for $600

http://cgi.ebay.com/ws/eBayISA...42910

$399.99 for 30 pounds 8 hours left on ebay

24 oz for maybe $25http://cgi.ebay.com/ebaymotors...14288

[DAEDALUS]

If it were that easy to find buyers actually willing to pay that much I would quit my job and broker R-12 all day. The last 30# I bought only cost me $350 cause the guy wasn't willing to ship and I lived close (enough). The average price even in winter has gone up noticeably in just the last couple years. It'll have to top out at some point, as soon as the demand starts to shrink faster than supply.

[Q45tech]

T3 has purchased 180 pounds so far this year at $650 per 30 pounds........we use around 210 pounds per year total for both shops.............. say 120 vehicles per year out of maybe 1100 that still use R12...........only a 12% annual failure rate!

When the customer allows us to fix them we fix them RIGHT so that they are good to go for another 6 years.

It is amazing when you notice how many Q/J/G and Lexus have their windows down in Summer traffic.........payback for owner abuse.