Danno

It was a tough debate whether the saved weight would be worth it in performance compared to the unbearable heat of driving across the Mohave desert.

Ok, so I decided to keep my air-condition on the car. Now I just need to recharge it. Got one of those R134a conversion kits with the new fittings and stuff. It gave directions and everything referring to the 'high-pressure' and 'low-pressure' side of the system. The same thing with the 944 manual. What neither set of directions explain is where the high- & low-pressure fittings are ?@#%$!!? Which one is the schraeder valve on the top-rear of the air-con compressor? I assume it's the low-pressure one since it's the only one that fits the low-pressure quick-release adapter that came with my kit?

sm

I was wondering the same thing today. Is the valve on top of the compressor the one we use to recharge the system? And how many pounds of refridgerant, R-12, do we need again?

Thanks!

Bri Bro

My valves are near the drivers shock tower. I will go through the cycle so bear with me.

The line that comes from the compressor to the condensor (in front of the radiator) is the high preasure line. The compressor pumps gas to a higher preasure and this heats the gas, the high preasure hot gas is cooled in the condensor and converted to a liquid. The receiver/dryer (under the drivers headlight, has a view glass) seperates gas from the liquid and removes any moisture. This high preasure pipe (smaller one closest to the shock tower, should feel hot) goes to the expandor inside the car. The expandor lowers the preasure of the liquid which lowers the temp of the liquid. The liquid enters the evaporator inside the car and the warm air from the car passing through the evaporator boils the liquid into a gas. This removes heat from the air ie cool air. The low preasure gas returns to the compressor (larger line next to the drivers shock tower, should feel cold) and the cycle repeats.

In hot climate I would suggest you stay with R12. If you change to R134A there are some steps that should be followed.

<a href="http://www.forparts.com/techretrofit.htm" target="_blank">R12 to R134A</a>
<a href="http://www.epa.gov/ozone/title6/609/retrguid.html" target="_blank">Retro fitting to R134A</a>

OK, you can't buy R12 without a EPA part 609 (cars) technician certification. Well if you can't pass this test you need to go back to grade school. It costs less then $20 and you are now allowed to buy and install R12 into your car. Take the open book test over the internet and get your licence number the second you pass the test.
<a href="http://www.autofrost.com/order/ordering.html#epacert" target="_blank">609</a>

sm

beab:

Thanks for the info. So I assume the low pressure valve (on larger line next to driver's side shock tower) is the one used to recharge the system? Not the one on the compressor?

Thanks

Bri Bro

Correct, connect to the low preasure (cold) line. If you connect to the high preasure side your can could EXPLODE. The system holds 900 grams (2 Lbs)of R12. Also keep the car upright while filling, this allows gas to enter the system rather then liquid. The compressor likes to pump gas, not liquid. Run the A/C with the fan on high, windows open when filling, this keeps the compressor running. Fill until the view glass doesn't show bubbles, don't over fill it. Gauges are nice but not required.

Dsalillas

[quote] Also keep the car upright while filling... <hr></blockquote>


The car or the can?

Bri Bro

Thanks...The car NEEDS to be upright and the can should also be upright.

Danno

Hey thanks, just what I needed!