A/C was working, now compressor runs, but no cold air.When compressor starts and stops, pressure does not change on low side. Is there a filter that could be plugged?

probably overcharged the system and now the high pressure switch is stopping the ac from working
did you fix the leak first

Does it start off blowing cold then goes to room temperature, or was it cold and now any time you turn it on its room temperature

Low freon will cause the compressor to short cycle, when the compressor runs the pressure in the low line is pulled down and the low pressure switch turns it off. Not running the pressure builds up and turns it back on. In the old days there was no low pressure switch, with no freon to carry the oil the compressor was destroyed.

see this causes and fix it. God bless you
Compressor Checks
Start with the compressor. Does it engage when you turn on the A/C?
If so, the compressor is working and the A/C system probably contains enough refrigerant to make cold air, so the problem is inside the HVAC unit. Replace the motor that controls the blend air door (this is a difficult job and best left to a professional since it involves tearing apart the HVAC unit -- about an 8 to 10 hour job!).
If the compressor does not engage when you turn on the A/C, see if it will run by jumping the compressor clutch wire directly to the battery (use a fused jumper wire). If the compressor works when you jump it, and the A/C blows cold air, the system contains refrigerant and the fault is likely a bad A/C compressor clutch relay or a bad clutch cycling switch or pressure switch.
If the compressor does not engage when you jump it, the problem is a bad compressor clutch.
If the clutch engages but the compressor does not turn (the belt will start to slip and squeal), the compressor is locked up and you need a new compressor.
If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged.
Refrigerant Checks
Connect an A/C pressure gauge to the HIGH SIDE service port (located in the high pressure hose that runs between the compressor and the condenser in the front of the engine compartment). The gauge will tell you if there is any pressure in the system. Simply depressing the service fitting valve with a small screwdriver to see if any refrigerant squirts out is NOT an accurate check because it tell you how much pressure is in the system. It may still have some pressure but not enough to trip the low pressure safety switch so the compressor will engage.
If your A/C system is low or out of refrigerant, check for leaks, then have the A/C system vacuum purged to remove air. After the air is out, it can be recharged with the specified amount of refrigerant. It is important to get any air out as this will reduce cooling efficiency and may make the compressor noisy.
A/C System Functional Checks
If the refrigeration circuit seems to be working (refrigerant in the system, compressor running and building pressure), but there is still no cooling, the problem might be an obstruction in the orifice tube (located in the high pressure hose between the condenser in the front of the radiator, and the evaporator located in the passenger compartment). A blockage here will prevent the refrigerant from entering the evaporator or recirculating through the refrigeration circuit.
If the orifice tube is plugged, the high side pressure reading will be lower than normal, and the low side reading will also be lower than normal because no refrigerant is circulating through the system.
If the refrigeration circuit seems to be functioning normally (compressor running, frost or condensation on the high pressure line from the condenser to the evaporator), but no cool air is blowing out of the ducts inside the car (and the blower is working), the fault is likely a BLEND AIR door that is stuck in the HEAT position, or possibly a badly clogged cabin air filter that is restricting airflow. Another possibility would be a fault in the automatic climate control system such as a ad interior temperature sensor or control module.

it's either low (in spite of your readings) or your a/c clutch is not working correctly or you have too big an air gap in the clutch.
First, just disconnect the 2 pin connector from the a/c pressure cycling swithc and jumper the 2 pins with a wire to force the clutch to stay engaged. See if it blows cold then, and stays engaged. You can run this way for about 15 minutes before you have to pull the plug.
report reulsts.

please don't forget to rate.

you really need to service an air conditioner with all the professional tools what are the pressures on the low side and the high side ? what coolant did you put in ? and how much ? r134a will only work if its done right too much and it will blow warm too little and the same thing you need the right amount did you change the receiver drier ? its a moisture filter it only works for about 5 years or once it gets moisture in it then its no good and needs to be changed also most gm's use an orifice tube filter in the high side line it too needs to be checked and cleaned or replaced . if the gauge needles are jumping around the compressor is bad . if the pressure is high on the low or high side over specs = no cold air . hope this helps

80lbs on the low side is WAY too much if the clutch is running, the high side you should see 125-150ish, the low 30-40. I would feel the lines (the bigger line going into the firewall to see if it is cold when your pressure is right) if so suspect a blend door motor which controls the hot and cold switching inside.

What you are referencing is probably the orifice tube + a screen.
There are many things that can change the air temperature inside the car.
1. Inside AC/HEATER duct under the dash, the temperature door can be open a bit and let the warm air mix with cold air temperature.
2.The purpose of the orifice tube, that is between the high pressure and low-pressure tube you can feel with your hands the cold and warm tube
The screen is blocking particles of metal from A/C compressor if the compressor is defect.

high-pressure side is HOT
low-pressure side is COLD
3. A/C compressor clutch could slip more than it should. The air gap has too much clearance.
The location of the orifice tube is :




New Orifice Tube EX 5151C 302272679 S10 Trailblazer Blazer DeVille eBay
To show you an example withdrawing and principle of A/C system and where to look for your question.

Hope it helps.

It sounds like you maybe low on freon and your a\c compressor is kicking in and out at lower RPM's because of low pressure,then you build enough pressure to keep it running at higher RPM's.

If compressor isn't kicking in, check the connector atop the a/c accumulator, beside the coolant recover tank, in the engine compartment. That connector is atop a black bottle, and the connector goes to the low pressure switch. These switches do fail, and you can jump a wire across the connector terminals to see if the compressor comes on (engine running). As this circuit provides part of the ground path from the compressor clutch, if the switch is open, the compressor will never turn on. If the switch is failed, it can be replaced without opening the a/c system. Just disconnect the connector, unscrew the switch, replace it, and reconnect the connector.