2002 taho location of orifice tube, ft and rear systems

freon ok ? compressor ok ? if both lines feel same either compressor not working or no //low on freon

Did you then draw a vacuum and charge the system?

The guage needs to read between 35/40 psi.. If its much higher you may be overfull, this causes it to not cool.. Fix by letting some freon out, then top it back to needed pressure.. If pressure is correct, it would be a clog in the system.. Usually an orafice tube or accumulator..good luck!

Is the system full of freon ?
The rear ac uses an expansion valve, and the front ac uses an orifice tube. One system can work independently of the other.

your local parts store can tell you exactly where to find it free of charge

probably needs freon. Add a can of R134a and see if it helps. they both run off same system but rear has exapnsion valve (more sensitive to low charge) than front fixed orifice tube design.

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.

Below is a guide to troubleshoot and check system function. This can be done by most folks.

Look at the front of the ac compressor and have someone turn on the ac from inside the car. The front of the pulley(clutch) will spin when turned on.

If it does not spin, the low pressure switch (LPS) is not satisfied. Meaning there is not enough freon in the system to operate the system. Means low freon capicity because of a leak.

The LPS can be jumpered to cause the compressor to run (clutch to engaged) which will draw the freon in the system.

The LPS is usually a two wire sensor on the suction of the compressor. (between evaporator and compressor) Unplug the sensor and install a jumper, this will engage the clutch. Connect a new can of freon
and fill to system capacity.

The capacity of the ac system will be on a label under the hood, do not overfill. Probably about 2 lbs. Local parts stores (Auto Zone and Advance) will have freon with stop leak. This may help the leak. They also make a freon with a UV dye. I always add a single can with dye so that if stop leak does not work I can find the leak in the future.

The system should be filled until suction pressure is about 30 to 38 psi..

Remember the flow for the a/c system is :
1. From the compressor a high pressure (HP) gas goes to the condenser in front of the radiator.
2. From the condenser a HP liquid goes to an expansion device (orifice tube or expansion valve)
3. From expansion device the low pressure gas enters the firewall to the evaporator.
4. From evaporator the low pressure liquid/gas mixture goes through the dryer back to the compressor suction.

try adding freon with a dye in it, sounds you have a leak,pay special attention to the a/c lines that run under the truck. notorious for having pin hole leaks,check these and get back to me we'll go from there. hope this helps get back to me Thanks Ray

The sensor on the back is a high side cut switch. If it blow out then you have a stuck orifice tube that needs to be replaced do to clogging up the system and causing a restriction. that is why the sensor switch blow. snap ring pliers will be needed