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?
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 >> Hi folks,
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)
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:
yrs jp
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
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