Not entirely OT, trust me.
I've done quite a bit of work on The Beater during the last few weeks, most notably installing a 4.5 inch bolt and bracket that was supposed to secure the engine cradle to the chassis. Prior to the repair, the left-rear of the engine cradle sagged a few inches down and slopped around quite a bit. This not only created noise, but horrendous handling on the highway. And of course, after bolting this thing back up properly, it had to be re-aligned. One of the rear shocks was also frozen in place, and I had to change both out. Much better handling now, oh yeah.
Even more interesting was the R-134a changeover. I changed out the accumulator/dryer unit, popped the old orifice tube out and used this fitting to blow out all of the old oil with some compressed air, (surprise: no oil came out - the system was completely dry!), installed a new VOV, installed 12 oz. of PAO oil (ester, not PAG) and about 18 oz. of refrigerant, just enough to get the high-side pressure up to about 325 psi.
What a difference! On a 100 degree day, the air comming out of the vents will nearly cause frostbite. In less than one minute, the ambient temp drops to the mid-70's, and will dip into the 50's in just a few more. Astounding performance. I would have never believed that the system in this stupid old beater car could ever work so well.
I did not evac the air/moisture out of the system prior to filling. Normally this is not a good thing. I gambled that the desiccant in the new dryer would take care of the moisture, and that the extra air in the system would not dilute the refrigerant enough to make a significant difference. I ended up being right on both issues. With a little luck, the seals, hoses and compressor won't die because of the high pressures and corrosive nature of the new refrigerant. So far, so good.
A note that specifically pertains to Mustang owners:
One reason that the changeover worked so well is because of the VOV I installed. It looks similar to a normal orifice tube, however the internals meter the refrigerant more efficiently, resulting in much cooler temps at idle and less compressor flooding. In fact, the compressor works less at idle than at highway speed, yet maintains excellent cooling performance.
Anyone who has the A/C repaired/maintained on their Mustang should have one of these installed. They work incredibly well, and will boost the performance of any automotive R-134a system out today.
The cost for this little gem: $4.95. They can be bought online, or as I did at Kragen. The counter help was completely ignorant, and I had to insist they give me a specific part number I obtained online; none knew anything about VOV's, so be prepared for this if you obtain one this way.
-JD
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