1990-1993 Evaporator Expansion Valve, Questions?

Hi folks,

My '91 Miata Expansion Valve needs replacement. But how do I get at it
and what is involved in getting my hands on the installed part to
replace it?

Any web links, photos, video or tutorials to help me and I hope the
following is the right part?

http://www.allworldautomotive.com/fe...d=220477361319

Pat

Pat wrote:
> Hi folks,
>
> My '91 Miata Expansion Valve needs replacement. But how do I get at it
> and what is involved in getting my hands on the installed part to
> replace it?
>
> Any web links, photos, video or tutorials to help me and I hope the
> following is the right part?
>
> http://www.allworldautomotive.com/fe...d=220477361319
>
> Pat

The A/C system is one of my weakest points, one of the only four or so
areas that I leave to people that do it for a living.

There have been people very familiar with the A/C systems here in the
past. All gone, maybe?

My next step, if I were you, would be to take this issue to the
miata.net forum.

Good luck!

The other Pat

My thoughts exactly. I would leave this matter to the professionals. I have
had my A/C serviced by a specialist that could replace parts, pressure-test
the system thoroughly and refill with the original R12 coolant. R12 is toxic
for the environment so always take care handling this stuff. Furthermore the
system is tested at 20bar (290psi) so all connections must be fully tight.

Jeroen
Technical Commissioner
Mazda MX-5 Club of the Netherlands

"pws" > schreef in bericht
...
> Pat wrote:
>> Hi folks,
>>
>> My '91 Miata Expansion Valve needs replacement. But how do I get at it
>> and what is involved in getting my hands on the installed part to
>> replace it?
>>
>> Any web links, photos, video or tutorials to help me and I hope the
>> following is the right part?
>>
>> http://www.allworldautomotive.com/fe...d=220477361319
>>
>> Pat
>
> The A/C system is one of my weakest points, one of the only four or so
> areas that I leave to people that do it for a living.
>
> There have been people very familiar with the A/C systems here in the
> past. All gone, maybe?
>
> My next step, if I were you, would be to take this issue to the miata.net
> forum.
>
> Good luck!
>
> The other Pat
>

Real R12 is getting hard to find and expensive to come by, at least in
the US.
Basically what is required is that the existing R12 be reused. This does
require the use of a system usually found only in a professional shop or
in a school's automotive shop.

Conversion to another coolant is possible, with some cooling ability
loss. (Usual solution).

Total conversion of the system with one designed for "modern" mandated
coolants is expensive, and seldom done.
But, it's possible, and reasonable in cost if you have time and junkyard
parts available.

One problem with some of the currently used/approved coolants is that
they are flammable. (some are propane based)



On 6/20/2010 4:51 AM, Jeroen Feelders wrote:
> My thoughts exactly. I would leave this matter to the professionals. I have
> had my A/C serviced by a specialist that could replace parts, pressure-test
> the system thoroughly and refill with the original R12 coolant. R12 is toxic
> for the environment so always take care handling this stuff. Furthermore the
> system is tested at 20bar (290psi) so all connections must be fully tight.
>
> Jeroen
> Technical Commissioner
> Mazda MX-5 Club of the Netherlands
>
> > schreef in bericht
> ...
>> Pat wrote:
>>> Hi folks,
>>>
>>> My '91 Miata Expansion Valve needs replacement. But how do I get at it
>>> and what is involved in getting my hands on the installed part to
>>> replace it?
>>>
>>> Any web links, photos, video or tutorials to help me and I hope the
>>> following is the right part?
>>>
>>> http://www.allworldautomotive.com/fe...d=220477361319
>>>
>>> Pat
>>
>> The A/C system is one of my weakest points, one of the only four or so
>> areas that I leave to people that do it for a living.
>>
>> There have been people very familiar with the A/C systems here in the
>> past. All gone, maybe?
>>
>> My next step, if I were you, would be to take this issue to the miata.net
>> forum.
>>
>> Good luck!
>>
>> The other Pat
>>
>
>

Chuck wrote:
>
> Conversion to another coolant is possible, with some cooling ability
> loss. (Usual solution)...

I had a '93 and the R-12 Freon leaked out to where running the A/C
didn't cool the air at all. Rather than replacing it with expensive and
environmentally hazardous R-12, the guy who used to work on my car
converted the existing system to work with R-134A instead. What this
involved was draining out any remnant of R-12 in the system (this
requires some kind of special recycling equipment, as it is illegal here
to simply vent it into the air), replacing two valves, replacing the oil
in the A/C, and filling it up with the new refrigerant. The whole job
only cost me about $120. The A/C running R-134 wasn't quite as cold as
it had been when it was full of R-12, but it worked adequately well (and
I live in Florida, so my A/C gets a workout).

After a couple of years it leaked enough that I wanted to add more
R-134. You can buy a kit with a valve/pressure gauge at your local auto
parts store for about $20-30 and do this yourself. Unless you really
don't like getting your hands dirty you can save a few bucks by doing
this yourself. It's no more difficult than adding a quart of oil or
changing the air filter. Here's an illustrated guide:

http://autorepair.about.com/od/regul...recharge_2.htm

The kit I bought looks like this one:

http://www.amazon.com/Artic-Freeze-R...pd_sbs_auto_19

Start the engine and turn the A/C up to Max, take the cap off the inlet,
plug in the hose, and pull the trigger until the pressure gauge reads in
the "green zone" (40 psi or so), replace the cap, and you're done.
After you top off the R-134, it feels great the first time you get in
and crank up the A/C and all that nice cold air comes blasting out!

yrs jp

Chuck wrote:
> Real R12 is getting hard to find and expensive to come by, at least in
> the US.
> Basically what is required is that the existing R12 be reused. This does
> require the use of a system usually found only in a professional shop or
> in a school's automotive shop.
>
> Conversion to another coolant is possible, with some cooling ability
> loss. (Usual solution).
>
> Total conversion of the system with one designed for "modern" mandated
> coolants is expensive, and seldom done.
> But, it's possible, and reasonable in cost if you have time and junkyard
> parts available.
>
> One problem with some of the currently used/approved coolants is that
> they are flammable. (some are propane based)

My mechanic friend has a freon system that works with R12 and R134. It
was around $5,000.00, iirc, definitely not for the average shade tree
mechanic.
It is a nice-looking piece of machinery, and he has captured the R12
from 2 cars for me so far that I have parted out.

My 1991 Miata has no A/C at all, and the 1995 Accord had the entire A/C
system replaced for over $1200.00 last summer before I acquired it.

There is a receipt showing that the previous owner of my Miata paid
$20.00 to have the freon captured properly before removing the AC
components, which was nice to see, though I figured that they would at
least do it for free considering the value of R12.

Pat