A/C Recharging

[daniel cauchon]

Hi ya all....anybody knows for sure if 95 have r 134 or r12 ??

thanks

 

[andy stein]

Thats been answered earlier in this thread.....1994 started use of r134.

 

[DROFYM]

HI everyone, I just checked my preasure with the gauge that comes with the $30.00 kit from autozone. it reads that I have good preasure in it. Around 30 psi. Do I need to add more r134-a? or leave it alone. Damm im confused. I have a 98 2door. my problem is that I have my a/c on max and it blows cold then every few min it will start to blow warm then back to cold. can anyone help. My computer is so slow that it takes forever to search. thank you.

 

[Glacier991]

Was that pressure with the AC operating or just sitting there with the engine and/or AC off ?

 

[F14CRAZY]

I have a 93 limited what am I looking for on the sticker to know the difference if I have r12 or r134.

Ah yes. Under the hood, on the passenger side by the firewall there is the A/C thingy that's wrapped in silvery insulation. There's a sticker on that that says R134a or R12. My 93 Limited has R12, but that's the year that they crossed over so you can have either.

 

[DROFYM]

Hey Glacier991, the truck was running and the a/c was on max. whatcha think?

 

[Glacier991]

if you have 30 on the low side, and the system is running, not cycling rapidly, you should have DAMN cold air at the vents! If not suspect the blend door.

 

[Josh]

Can anybody tell me what the optimal preasure should be? I was told to keep it just enough to keep the pump working. This would alow the freon to work at its best. To much preasure and the system has a hard time with the heat exchange process. My system is currently around 45 PSI, but that is in the upper range of the safe zone.

 

[Blaine122300]

Can anybody tell me what the optimal preasure should be? I was told to keep it just enough to keep the pump working. This would alow the freon to work at its best. To much preasure and the system has a hard time with the heat exchange process. My system is currently around 45 PSI, but that is in the upper range of the safe zone.

I just went by the chart on the back of the gauge. If the outside temp is around 100* F then you want to get the pressure up to 55psi.
I feel if the compressor is running on-off-on-off, it will cause premature falure of the clutch. My pressure is in the upper portion of the "Safe" zone on the gauge and it runs cold. Just go by the instructions, and you will be good.

 

[Josh]

On the guage that I have, the yellow area starts at 46psi. Do I just disreguard the colors on the guage with the exception of the red? Also, what book are you refuring to? I don't have any documentation for my system and the Chiltos manual doesn't go into detail. Thanks

 

[Glacier991]

"Optimal" pressure is a myth... or unattainable. Even if just from scratch and recharge of an empty system according to factory specs, it's a trade off. Try duplicating it on a partly full system? Tough to do with precision. The pressures will vary depending on condensor cooling, evap load (hot cabin) etc. Look at a chart of pressure/temperature. You want the low side to be above freezing (around 32 lbs pressure for both R-12 and -134) but not too high (55 is high unless ambient is 100 degrees or above). At the same time you want enough refrigerant to carry oil - that is how your compessor gets lubricated! Operating pressures of 35 to 45 low and 220 to 275 high are good on a 134 system at 85 to 95 degrees - high side may go higher without airflow over the condensor. If I am topping up I will often tweak it by vent temps using a fan to cool the condensor. HTH.

 

[Blaine122300]

Couldn't have said it better myself.