legacycentral bbs

Hey all, wondering if you could help me with something. I bought a '93 legacy from this guy who says it's been changed over to use 134 but the compressor just needs replaced because whoever it was who put the compressor back on tightened the belt too much and that ruined it. Is this guy just blowin' smoke? Also, there's no documentation to prove the system's been changed to accept 134, would there be any other way to tell without taking it to a shop?

Unfortunately, there's really no way to tell what's in there. The AC systems in these cars can be converted to r134a pretty easily.

You can pick up a used compressor and try that. I didn't have the best of luck with used compressors, but that may have been because I used esther oil instead of PAG oil. As for parts, you can replace the compressor and the receiver drier, flush the system, put the proper amount of oil in, vacuum the system, and charge with r134a. The system still blows VERY cold. I'm still surprised at how cold my converted 90 Legacy blows compared to newer cars.

Here's my write-up
http://www.bbs.legacycentral.org/viewto ... =11&t=1083

Like I mentioned, I'd suggest using PAG 100 instead of esther oil.

thank you!

also the R134 uses different fittings in most case's, look at the high and low side ports if they are still screw on style fittings then its most likely still r12, r134 will have a quick connect fittings.

The compressor doesn't need to be unmounted to convert a system over. You don't even need to remove the belt. Story doesn't make sense but does the system get cold at all?

Yeah the HI and LO side fittings should give it away. They are a different size and are quick clip-on style (sort of like the quick disconnect fittings of air compressor lines). If you or a friend has one of the little hoses that clip on so you can shove a can of R134a into a system, if that fits on the LO fitting then it's been converted.

Actually, you do need to dismount the compresor. You need to remove the old oil from the compressor, it's mineral oil and not compatible with R134a. It may work for a little bit to just fill it with r134a, but will have issues over time.

Legacy777 wrote:Actually, you do need to dismount the compresor. You need to remove the old oil from the compressor, it's mineral oil and not compatible with R134a. It may work for a little bit to just fill it with r134a, but will have issues over time.

Oil change is not a bad idea, but I'm not going to immediately dismiss closed system retrofit here.

Here's Subaru official procedure from 2000 or so:
Basically, it calls for replacing the rubber lines, then adding 200ml (6.5 oz) PAG 100 oil, 73019AA110
vacuuming and filling the system up with 30oz of R134a.

That's for Zexel/Diesel Kiki setup. They prescribe 8oz oil and 24oz R134a for Calsonic system.

Even if you don't remove the compressor, I would still remove the drier then remove lines at compressor. Force air through both sides, one at a time and this will push out some oil out at the point of removed drier. Some removal is better than none.

Fit with new drier. Vacuum and do as above.


1. Retrofit kit P/N for 1990-91 Legacy is G3110AS000, for 1992 Legacy is
G3110AS010 and for 1993 Legacy is G3110AS020.
2. Always lubricate all o-rings with PAG oil before installation.
3. Always tighten fittings to proper torque specifications.
4. Observe all safety recommendations.
5. System to be serviced by qualified personnel only.

1. Repair any problems or leaks before beginning retrofit procedure.
2. Disconnect negative battery cable.
3. Recover all R-12 refrigerant from the vehicle’s A/C system utilizing a UL
approved R-12 recovery device.
4. Disconnect the electrical connection from receiver/drier pressure switch
and remove the existing R-12 receiver/drier from the vehicle and discard.
Allow as much oil as possible to drain from A/C hoses or pipes.
5. Use touch-up paint to paint the sight glass on replacement receiver/drier; P/N
73031AA210. The sight glass cannot be utilized in testing R-134a performance.
6. Remove and discard the receiver/drier o-rings and replace with new
o-rings, P/N 73039AA200.
7. Install the replacement receiver/drier, P/N 73031AA210, in the vehicle
and connect the pressure switch electrical connection.
8. Remove and discard the suction refrigerant hose, retain all hardware, and
add 200 cc PAG retrofit 100 oil, P/N 73019AA110, to the compressor.
9. Install new suction hose, P/N 73054AA620 (73054AA400 for ‘93 Model), using
all applicable OE hardware. Lubricate the suction hose o-rings before installation.
10. Remove the discharge refrigerant hose and retain all hardware.
11. Install new discharge hose, P/N 73054AA600 (73054AA630 for ‘92 Model
and 73054AA640 for ‘93 Model), using all applicable OE hardware. Lubricate
the discharge hose o-rings before installation.
12. Evacuate the A/C system for 30 minutes using R-134a equipment.
a. After 10 minutes close the manifold gauge valves and perform a vacuum
leak test.
b. After five minutes re-check the low pressure gauge reading. If the
vacuum level has changed more than 1 in HG, pressurize and perform
an electronic leak test of the system.
c. If no leak is indicated resume evacuation (remaining 20 minutes).
13. Charge system with 1.87 lb./30 oz./850 gm. R-134a refrigerant and