Recomended high/low pressures for an auto air conditioning system?

Answer 1

I'm glad you asked...

This is a complicated thing. The high pressure side will measure in excess of 250 psi, but that's not important. When filling 134a, you only need to watch the low pressure side.

When the compressor kicks on (which it will only do when the pressure is above 40 psi) the pressure will drop. If the lines are full enough, the pressure will remain around 40-45 psi while it's running. When the compressor kicks off, the pressure will rise to 90-100 psi., as the high and low pressure sides even out in the expansion tank.

If your lines aren't full enough, the compressor will either not kick on at all, or it will kick on for a second, and the pressure will drop to 20 psi or less, and it will kick off. If the lines are empty enough, it will do this on and off, on and off, pretty frequently, like every 5 seconds or less.

Be sure to hold the cans up-side-down and high in the air as you release them into the system. Otherwise, they will release much slower, as you will be releasing only what gas has expanded. NEVER connect the cans to the high pressure side. They will explode in your hand, not only removing your hand and eyes, but will also freeze your skin instantly.

Just keep applying cans until the pressure remains at 40-45, depending on your vehicle(it will find this pressure on it's own. you will see it remain there and not drop past a point. if it has not found it's point, it will never stop dropping till the compressor kicks off.) Do this a little at a time, stopping to watch the pressures.

Once you reach this steady pressure reading, finish off the can, and you can probably add another can or just a half a can. You don't want to add too much, or else the pressure will build up too much on the low side. If this happens, (and only if you have 134a) you can release the excess pressure from the valve just like you would emptying a tire. Be sure you do this on the LOW side, and do it while the vehicle is running, so you can watch the pressure. Be careful, and wear leather gloves if you have to remove some, because what comes out will freeze your skin.

Good luck and contact me if you have any questions about connecting your gauge manifold.

Answer 2

This Site Might Help You.

RE:
Recomended high/low pressures for an auto air conditioning system?

Answer 3

It's just dumb to say the high side (discharge pressure) doesn't matter !!!!!

It's all relative you have to factor in outside temp engine temp and interior temp

Typically at 1500 RPM's the low pressure should be 35-40 but again if you have a restriction the freon will not flow correctly and could cause a low suction pressure and extremely high head pressure that could cause serious damage to the compressor

Answer 4

Ac Pressure Chart

Answer 5

Depends on the ambient temp. but generally at temps around 85 the low side will be around 35 and the high side will depend on the restriction. Either an orifice or an expansion valve. With an orifice, it should be around 250 psi and with an expansion valve it should be around 300psi. Good luck

Answer 6

manual auto air conditioning is the same as the 4-55 air conditioneer. You roll down all four windows and drive 55 MPH.

Answer 7

high 250-300
low 25-45
too much freon is bad too little is bad also i have found it you are having trouble with he air not blowing cold or compressor cycling a little less freon can help

Answer 8

35/275

Answer 9

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Answer 10

berhow u dooshhh bag that's a link to a virus