An expert who has achieved level 3 by getting 1000 points
An expert that got 10 achievements.
An expert that got 5 achievements.
An expert whose answer got voted for 100 times.
Re: What are the charging pressures for the AC?
This is a temperature related question but with everything running well including reasonable air flow through condenser/radiator you will see up to 250 high and low needs to drop under 50 or more if optimal(but never towards a vacuum or zero pressure) ...compressor will cut out on high head at about 350 to 400 which is sky high...you are looking for a good differiential in pressures basically
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If your car ac is not taking in refrigerant, it could be caused by several things.
If you have recently done work on the system and you are going to fill the system the first time, you will need to pull a very deep vacuum before trying to charge in refrigerant. If you have already properly evacuated the system and having problems getting the correct charge adjusted, you may be having problem with pressure equilizing between the refrigerant source and your ac system. To get the refrigerant going again, you need to connect the charging hose on the low pressure side of the ac system and turn the fan and ac on cool. The pressure in the ac system on the low pressure side will get lower than the pressure in the refrigerant container and flow will start. When charging initially, charge liquid on the high pressure side and with the ac system running, charge gas on the low pressure side. To charge liquid, invert most container so spout is down, to charge gas, keep container right side up. Charging by gas help you to not over charge your system. Beware on most vehicle ac systems the suction and discharge connections are two different sizes and require the proper adapter. If you still having problems creating a pressure difference to move refrigerant, you can try immersing the refrigerant container in warm water or applying warm air to the exterior of the container.
Hope this helps.
LOW PRESSURE SIDE IS THE SUCTION CHARGE SIDE WILL BE FROM AC COMPRESSOR REFRIGERANT LINE TO THE ACCUMULATOR OR DRIER TO THE EVAPORATOR IN THE FIRE WALL THE AC COMPRESSOR LINE TO THE CONDENSOR IS THE HIGH PRESSURE SIDE YOUR DISCHARGE SIDE. DONT DONT TRY CHARGING AC SYSTEM AT THE HIGH PRESSURE SIDE. CHARGE AT THE LOW PRESSURE SIDE.
CHECK REFRIGERANT CHARGE. USING A MANIFOLD GAUGE SET. HOOK MANIFOLD GAUGE SET TO LOW PRESSURE PORT AND HIGH PRESSURE SIDE PORT. LOW SIDE PRESSURE SIDE SHOULD HAVE 25 - 36 PSI AND HIGH PRESSURE SIDE SHOULD BE 178 - 237 PSI. IF LOW SIDE PRESSURE SIDE READ BELOW 20 PSI THE LOW PRESSURE SWITCH WILL NOT TURN ON THE AC COMPRESSOR CLUTCH NEED TO ADD LITTLE MORE REFRIGERANT. IF REFRIGERANT LEVEL CORRECT CHECK AC COMPRESSOR FUSE AND RELAY.IF POWER GOING TO AC COMPRESSOR CLUTCH YOUR COMPRESSOR CLUTCH HAS OPEN WINDING. AC COMPRESSOR CLUTCH NEED REPLACING.
The low pressure port is the only one that your AC charging tool will fit on if you are planning to charge the AC unit with refrigerant. The high side port is much larger and the quick connect tool won't fit it. Look up high toward the firewall on Fords and Lincolns.
YOU NEED A R-134 GAUGE SET TO CHECK LOW PRESSURE SIDE AND HIGH PRESSURE SIDE.YOU ALSO CAN BUY A LITTLE CHEAPER GAUGE TO CHECK YOUR AC LOW BLUE SIDE AND HIGH RED SIDE AT ANY AUTO ZONE OR ADVANCE AUTO PARTS.WHAT YOU DO WHEN YOU GET YOUR GAUGE SET HOOK GAUGE TO LOW PRESSURE SIDE BLUE CAP PORT AND GAUGE TO HIGH SIDE PRESSURE RED CAP PORT.YOU CRANK CAR UP GET IT OPERATING TEMPERATURE.THEN TURN AC ON HIGH COOL LET RUN 3 TO 4 MINUTES.CHECK LOW SIDE GAUGE READING SHOULD BE 28 - 32 PSI. HIGH PRESSURE SIDE GAUGE SHOULD 199 - 228 PSI. THATS NORMAL CHARGE. SEE YOU CANT JUST RECHARGE AC SYSTEM UNTIL YOU CHECK IT FIRST YOU WILL DAMAGE SYSTEM .NOW YOU CAN GO TO AUTO ZONE PARTS BUY A CHARGE CAN WITH GAUGE AND HOSE.ATTACH TO IT.YOU NEED MORE THAN ONE CAN.WARNING MAKE COMPRESSOR IS RUNNING WHEN YOU TURN ON AC .BECAUSE IF COMPRESSOR NOT RUNNING CHECK FUSE AND AC COMPRESSOR RELAY.IF BOTH OKAY.YOU COULD HAVE OPEN CLUTCH COIL A FAULTY LOW PRESSURE SWITCH WILL CAUSE AC NOT TO WORK. IF LOW PRESSURE GAUGE BLUE SIDE PRESSURE IS 28 OR 30 YOU DONT NEED A CHARGE.PROBLEM SOME WHERE ELSE.BE SURE TO WEAR SAFETY GLASSES WHEN WORKING ON AC SYSTEM.
A/c should be charged on the low side while engine is running. Make sure high side valve is turned off. Low side reading should be around 32-35 psi at idle high side should not go above 250. I hope this helps,good luck
whenever the ac system has been opened it should be hooked up to a vacuum pump designed to evacuate the ac system of any foreign debris and oil etc and after should be able to hold a vacuum to show that there are in fact no leaks then if all is ok at this point you can then charge your ac with the proper freon specified for you car when the pressure reaches satisfactory level the ac compressor will then cycle on you should not bypass the low pressure switch
There are two A/C refrigerant lines. The small line is your high pressure line and the larger line is your low pressure line.
Start at the fire wall and follow the "large " low pressure line to the compressor. The low pressure charge port will be some where on that line.
DO NOT try to recharge on the high pressure side ( small line )
Good luck, let me know.