A/C Conversion-What's Involved?

[email protected] wrote in news:7c7de3ab-48c1-4004-af73-2f79137e3d28
@m36g2000hse.googlegroups.com:

> I have a very low mileage (23k) Acura Legend, 1990 which I have to get
> the A/C recharged on. Its still the old R12 system and I'd like
> opinions on whats involved in changing over to 134a? Easy? Expensive?
> Worth it? TIA
> Jay



If there's no leak, don't convert! Just get it recharged with R12.

Automotive A/C systems naturally leak roughly an ounce every year, so a
system with one pound of refrigerant will be at zero pressure after roughly
16 years even if there is no actual "leak".

Have your garage check for leaks before anything else.

--
Tegger

<[email protected]> wrote:
>I have a very low mileage (23k) Acura Legend, 1990 which I have to get
>the A/C recharged on. Its still the old R12 system and I'd like
>opinions on whats involved in changing over to 134a? Easy? Expensive?
>Worth it? TIA

Depends. You can do it right, half-assed, or screwy. The right way
involves changing the evaporator coils, cleaning the whole system out,
draining the oil out (often involving pulling the compressor off), adding
new oil, pumping it down, and repressurizing it. The half-assed way involves
cleaning the whole system out, draining out all the old oil, putting
in new oil, pumping it down, and repressurizing it. The screwy way
involves putting new oil in and hoping that most of the old oil is
already out and that what is left is miscible, pumping it down without
cleaning anything, repressurizing and praying.

The cost difference between these three, both in parts and labour,
is substantial. Oh yes, you also need to fit on new fitting adaptors
in all cases, and I'd replace the dryers just in case....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[email protected] wrote:
> I have a very low mileage (23k) Acura Legend, 1990 which I have to get
> the A/C recharged on. Its still the old R12 system and I'd like
> opinions on whats involved in changing over to 134a? Easy? Expensive?
> Worth it? TIA
> Jay

You would probably be better off staying with R12. Just have any actual
leaks repaired and recharge. The price of R12 has come down a LOT.

--
Steve W.
Near Cooperstown, New York

<[email protected]> wrote in message
news:7c7de3ab-48c1-4004-af73-2f79137e3d28@m36g2000hse.googlegroups.com...
>I have a very low mileage (23k) Acura Legend, 1990 which I have to get
> the A/C recharged on. Its still the old R12 system and I'd like
> opinions on whats involved in changing over to 134a? Easy? Expensive?
> Worth it? TIA
> Jay

I did it with my 90 Buick Reatta.. Nobody here even stocks R12 anymore.
Some
will put in a can or two of refrigerant blend, which may work, or may make
things
worse.

In my case I had to change the compressor anyway, because the old GM pos was
leaky around the seal.

Since there were no other leaks, I flushed the black death out of the
system, replaced
the R12 fittings with 134a ones, replaced the accumulator (filter drier).

It was done correctly, and the parts ran me about $300-400

HLS wrote:
>
> <[email protected]> wrote in message
> news:7c7de3ab-48c1-4004-af73-2f79137e3d28@m36g2000hse.googlegroups.com...
>> I have a very low mileage (23k) Acura Legend, 1990 which I have to get
>> the A/C recharged on. Its still the old R12 system and I'd like
>> opinions on whats involved in changing over to 134a? Easy? Expensive?
>> Worth it? TIA
>> Jay
>
> I did it with my 90 Buick Reatta.. Nobody here even stocks R12 anymore.
> Some
> will put in a can or two of refrigerant blend, which may work, or may
> make things
> worse.
>
> In my case I had to change the compressor anyway, because the old GM pos
> was
> leaky around the seal.
>
> Since there were no other leaks, I flushed the black death out of the
> system, replaced
> the R12 fittings with 134a ones, replaced the accumulator (filter drier).
>
> It was done correctly, and the parts ran me about $300-400

One other item. Since R134 isn't as efficient as R12, the
condenser size needs to be increased to match the cooling
capacity of R12. This can cost a small piece of change. Of
course you can omit this step and bear with the decreased
cooling capacity. I'm not really aware of the % of
difference and it may very well be transparent to some..

"bobj" <[email protected]> wrote in message news:CQlgk.1251
> One other item. Since R134 isn't as efficient as R12, the
> condenser size needs to be increased to match the cooling
> capacity of R12. This can cost a small piece of change. Of
> course you can omit this step and bear with the decreased
> cooling capacity. I'm not really aware of the % of
> difference and it may very well be transparent to some..

It was not necessary to replace the condensor, and the car works fine with
the new conversion. Do it if you wish, but IMO it is not necessary.

On Sat, 19 Jul 2008 12:48:28 -0500, "HLS" <[email protected]> wrote:

>
>"bobj" <[email protected]> wrote in message news:CQlgk.1251
>> One other item. Since R134 isn't as efficient as R12, the
>> condenser size needs to be increased to match the cooling
>> capacity of R12. This can cost a small piece of change. Of
>> course you can omit this step and bear with the decreased
>> cooling capacity. I'm not really aware of the % of
>> difference and it may very well be transparent to some..
>
>It was not necessary to replace the condensor, and the car works fine with
>the new conversion. Do it if you wish, but IMO it is not necessary.

What works well may depend on the car/system. About 7 years ago I
took my 1990 Corsica 2.2 to my mechanic when I was using him for my
car work. Wanted a shot of R12 because the cooled air had warmed up a
bit.
He suggested he convert it to R134, and said he'd do the whole thing
for a little over $100. Just change fittings, evacuate the R12 and
refill with R134.
I mentioned reading that you needed a new compressor, hoses, blah,
blah, and he said he'd had good luck just doing the fittings on this
system, and there was little to lose. Think he charged me @$120.
Worked good the rest of the summer, the next summer, and almost the
whole third summer. Then I came home from work one day and heard
hissing as I exited the car and saw an expanding oil spot on the
street under the condenser where the hissing was coming from.
Could well have been a stone bounced up on it and holed it. Don't
know. Never bothered doing an autopsy on it. Might have been a
compressor failure put undue pressure on a weak spot in the condenser,
but I don't know enough about it to say. It was blowing cold until
that moment.
Since by now my kid was gung ho to fix anything automotive, had a
gauge set, evac pump, etc, I popped for a new condenser and he put it
on.
Big mistake since it turned out the compressor was shot too and I
didn't care enough about A/C on that car to buy a new one.
So that car has been running around the last 4 years or so with a
$300 new condenser but no A/C.
Yeah, yeah. Seems a waste, but I'm a firm beleiver in not throwing
good money after bad. I've never missed the A/C much even on hot
days. Around here (Chicago area) you might use it 30-40 days a year,
and I don't wear a suit any more so it's no big deal.
The car I take to Florida is the one that really needs A/C.
The kid is coming over today to a do final strip of the '93 Corsica
3.1 he's junking and said if the bolt patterns match he'll throw the
'93's compressor, which works fine, on the '90 just for kicks.
I've noticed some difference in the air temps between R12 and R134
on GM cars, but if the R134 system is performing correctly it doesn't
matter much. The only difference I notice is that with R134 women
don't bitch as much about their arms getting cold.
I posted recently about travails fixing my '97 Lumina A/C, which is
fine now, BTW.
My biggest advice where I know exactly what I'm talking about
regarding the GM systems as used on the '97 Lumina et al is:
Buy new OEM compressors only. The price diff over a reman just ain't
worth the risk of redoing everything. In my case TWICE.
Don't trust Murrays Auto Parts to have A/C o-rings on the
dryer/receiver they sell. The R134 went through their supplied
o-rings in a couple days.

--Vic

"Vic Smith" <[email protected]> wrote in message
news:68c4845d0spucetmk4p1mc6j6vltlbje3a@4ax.com...
> On Sat, 19 Jul 2008 12:48:28 -0500, "HLS" <[email protected]> wrote:
>
>>
>>"bobj" <[email protected]> wrote in message news:CQlgk.1251
>>> One other item. Since R134 isn't as efficient as R12, the
>>> condenser size needs to be increased to match the cooling
>>> capacity of R12. This can cost a small piece of change. Of
>>> course you can omit this step and bear with the decreased
>>> cooling capacity. I'm not really aware of the % of
>>> difference and it may very well be transparent to some..
>>
>>It was not necessary to replace the condensor, and the car works fine with
>>the new conversion. Do it if you wish, but IMO it is not necessary.
>
> What works well may depend on the car/system.

Could be true. I bought all my parts from www.ackits.com
These are good people with a wealth of information.

If your "mechanic" switched refrigerants without washing out the system
and adding compatible lubricant, you were doomed to problems.

You dont necessarily have to have a new compressor (unless the old one is
crappola like mine) but you DO have to use compatible lubricant.

You dont charge 134a and 12 in the same ratio either.