R134 pressure What should the high and low side pressure be?

Typical R134 pressures are 25-35 p.s.i. low side and 200-300 p.s.i. high side, all measurements taken with ambient temperature above 85 degrees farenheit. At idle, with fan high and system in recirculate mode, you should be able to attain an output temperature at the vents of 40 degrees below ambient.

2.5 lbs sounds like a lot of gas thats about 1.1kgs ,anyway i think it will work on around 800grms of R134 ,now use the same weight of gas but start around the 800 grms mark as too much gas will hold the engine back ,Now R134 gas is different in its cooling properties and the pump pressures are different as it doesnt need such a high pressure or a big cooling radiator ,i have no idea where the fillers are but look pump for the fattest tube and follow this back to the firewall and you will find the low pressure connection here.Fit the adaptor here for the R134 and then if you havent a vacumn machine to do it properly just start engine and turn AC on with the fan motor and let it charge and as the pressure builds up the pump will click on and **** the gas in for you.Now remember that as R134 need a bigger cooling radiator to cool the high pressure hot gas so the smaller rad used for R12 will not be as efficient it will work when moving better than stationary so make sure that the exterior of the rad is well clean and no dead bugs on it .As stated it will work and if you have any R12 gas still in the system it will mix ,I mix CO2 from a beer barrel gas bottle into my machine with R134 as its so much cheaper iam paying 248euros for 15kgs of R134 so the average car of 750 grms is costing me about 14 euros in gas alone without the 2500 euros for my machine

buy r134 can w/pressure gauge at local parts or department store. Folllow directions on can as far as application. The valve only fits the low pressure line, so there is no way to accidentally attempt charging high pressure side. Unscrew cap, attach valve of r134, check gauge. if fully charged already, do not overcharge... won't cool better, only cause damage.

can't be.the larger port is the HP side, and the hose on your can will only fit the low (small) pressure side-you CAN fill a system on the HP side, engine off, by hooking up to the HP side and inverting the can so that liquid 134a fills the high side-but it is not recommended if you do not have manifold gauges and aren't experienced with AC systems.

Hi, determine if your car uses R134 or R12 refrigerant. You will notice screw type connectors on the both the High Pressure Side and Low Pressure Side lines in models using R12 refrigerant. R134 compatible models have quick connect valves on both sides. Models made before 1995 may use the old R12 refrigerant. If this is the case, you must have your Chrysler's air conditioning system retrofitted to use R134 refrigerant. Mixing R12 and R134 refrigerants is dangerous and may cause damage to your vehicle. Check your air conditioning system pressure using an automotive air conditioning pressure gauge. Keep in mind that in order to get an accurate reading, the air conditioner has be turned on the coldest setting with maximum blowing power. Remove the Low Pressure Side port valve cap and set it aside. The location of the port varies, but it is usually in front of the engine block. Attach the refill hose to the port on the Low Pressure Side of the air conditioning system. The Low Pressure Side port is smaller the High Pressure Side port. Because the ports are different sizes, the refill kit hose should fit only on the Low Pressure Side port. Additionally, the High Pressure Side port will usually have a red cap or be marked with an H or the word High Allow the air conditioner to **** the refrigerant out of the can by slowly turning the valve on the refill kit hose. Pay attention to the way you hold the can. Most kits will have you hold the can upright when you recharge the air conditioning system. It may take as long as 10 minutes to empty a single can. Turn the valve to the off position and remove the refill hose from the port. Recap the port before closing the hood. Let the air conditioner stay on for at least 30 minutes. This allows the refrigerant to move throughout the entire system.
Take care

Closer to firewall is where your low side port should be. Your R134 filling hose quick connect adapter will ONLY fit on the proper "low side" connector port at that location because it is a different size than the high pressure port. You can't put it on the wrong port and get it to fit.

Find the a/c compr, look for the thick a/c line, follow the line will come to an a/c port to charge a/c, stay away from thin a/c line that one is high pressure, low side a/c hose adaptor will only go on low side fitting, will not fit on high side.

As long as you know you evacuated completely , then the high side doesn't matter too much . The low side should read about +10 , if your using R134 .

Should be right on the compressor.
Follow the low side hose back to the compressor.
If it has not been converted from PAG-46 refrigerant you will need to flush and refill.
If it HAS been converted to R-12 or 134a already - you will have to unbolt the compressor to charge - as there isnt enough clearance with the adapter installed to get the coupler on.... and it is charged on the HIGH side in this scenario... since the car is not on.

Evacuate PAG-46

• Hookup gauge set to high side, low side, and vacuum pump.
• Open valves and run vacuum pump for 30 minutes, to boil off all moisture.
• Close valves and make sure vacuum is held. If not, there is a leak.

Then Fill with R-134a

• Jumper low-pressure cutoff switch (next to left headlight)
• Hook up R134 can to hoses (purge air from line)
• This is a good time to add oil, if needed. Pour some in the hose, the R134 will push it into the system.
• Open high-side (red) valve. This will let some of the R134 go into the system.
• Once you've got as much as will go in there (putting the can in warm water helps), close the high-side valve.
• This is very important. If you don't close the high-side valve before you start the car, the can might burst. That would be bad.
• Start the car and press the a/c switch.
• Open the low-side valve (the one going to the compressor) and let it s uck in the R134. S uck s uck s uck.

HERE is the TSB for conversion if you're interested.


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Your focus should not take freon. Freon is used in older cars from 1995 on back. Your focus should take R134 and the plug for your AC should be located under the passenger side wheel well (yes ford makes things so convenient). Just unscrew the little plastic crews in you wheel well and attach the gauge and can of R134 (should take a little more than 2 large cans).