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A/c system the high side line gets very hot ?

The high side line gets very hot on a/c system?

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Yes. One line gets hot and the other gets cold. The freon gas carries hot air out of the passenger compartment and expells it from the condenser. The freon gas changes from gas to liquid and back again.

Posted on Jul 12, 2013

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Ac will not blow cold hot ac lines

Is the system full of freon ? Is the radiator fan working ?

Jul 06, 2013 | Cars & Trucks

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My a/c compressor is not working

If one line is cold and one hot the system is working normally, so the compressor is not the problem.

Jun 29, 2012 | Cars & Trucks

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Where is low side port on Yukon

{: ) To distinguish low side and high side lines in an a/c system, the low side uses thicker sized tubes and hoses, and usually cold to touch when the a/c compressor is at work. The thinner high side lines is usually warm or hot to touch.
The low side service port or valve is usually mounted along the low side lines, near( or at) the a/c accumulator. The accumulator is that aluminum type can mounted against the right side area of the firewall.

Jun 07, 2011 | 2003 GMC Yukon XL

1 Answer

Low side port

{: ) To distinguish low side and high side lines in an a/c system, the low side uses thicker sized tubes and hoses, and usually cold to touch when the a/c compressor is at work. The thinner high side lines is usually warm or hot to touch.
The low side service port or valve is usually mounted along the low side lines, near( or at) the a/c accumulator. The accumulator is that aluminum type can mounted against the right side area of the firewall

Jun 07, 2011 | 2003 GMC Yukon XL

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Where is the orifice tube located on a 1992 grand marquis ls

Hi, the orifice tube always goes in the high side , the thinner line, most of the times close to the easy way to find it is touch with your fingers the line ,in some place will be hot and in another cool , when it change from hot to cool there is the place, most of the time is close to the line connection....

Sep 24, 2010 | 1992 Mercury Grand Marquis

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I have a 1994 chevy c1500 with a 305 motor. when i turn on the A/C the clutch engages/disengages continuously but no cold air. Any ideas?

Your A/C system may be running low on R134a.
To diagnose problems, an A/C manifold gauge set is needed to read high and low side pressure readings. Avoid adding refrigerant with a simple charging kit like the ones sold at parts stores. Don’t add any stop leak, this can cause problems in the compressor, expansion valve or condenser.
First, on a 134A system the high and low side service ports are different sizes. AC gauge sets have color coded hoses, the blue color coded hose has a connection that fits on the low side service port and the red hose has a connection that will only fit onto the high side. The yellow hose won’t hook up to anything if just checking the readings; it can be used to connect to a vacuum pump or attached to a refrigerant can or tank.
Normal readings on high and low side with AC OFF (static pressure) – Depends on outside temperature, but normally is between 80-105 PSI
Normal low side reading with AC on high speed and MAX & engine at 800-1000 RPM’s – Ranges from 25-35 PSI – Note that on many Chrysler products a normal reading on the low side may be 15-25 PSI
Normal high side reading ranges from 200-350 PSI
Don’t assume that if adding little Freon is good that adding a lot is better! Overcharging just a little can decrease the performance of the system and possibly damage the compressor.
With the AC on the coldest setting, use a thermometer in a middle vent. Normal vent temperature readings will vary depending on the (ambient) outside temp. The vent temperature should range from around 42-55 degrees in my experience. If normal gauge readings are obtained and the vent air is cold – STOP don’t overcharge the system. The only proper way to remove refrigerant is with a AC recovery machine so if this is being done at home I can’t emphasize enough not to over charge the system. And actually the best way to insure the proper charge is in a system, is to use an AC machine to recover the freon and then evacuate and recharge the system with the correct amount. Most cars have the specified amount on a decal under the hood.
Both low and high side readings are lower than normal, this indicates a cars AC system is low on refrigerant and is under-charged.
If both low and high side readings are too high, this indicates an overcharged system – too much refrigerant. This also can indicate that the condenser fan is not working, is too slow or the car is overheating and heat is transferring from the radiator to the condenser.
When the low side goes so low that it’s reading shows it is in a vacuum, the most likely cause is a bad expansion valve or blocked orifice tube. Another possibility is a restricted condenser. Blocked condensers are not as common as they used to be but if a compressor fails and comes apart inside the remnants can end up in the condenser causing it to restrict the flow of refrigerant.
When the compressor clutch is definitely engaged and the low side is high and the high side is low, the most likely cause is that the compressor is failing – it is not pumping sufficiently. Rarely an AC clutch could be slipping but usually this will be accompanied with a squeal or chirp. Also be sure not to overlook the obvious, like a loose belt
Note: The line going from the compressor to the condenser is the discharge line – it is normal for it to be very hot to the touch. The other line going from the drier or accumulator to the compressor is normally colder. The liquid line can be hot up to the point an orifice tube is in place. Just remember that LOW Pressure = COLD and HIGH Pressure = HOT.
If you do want to recharge the system your self, make sure you do not over charge and use the thermometer at the vent and when it's cold enough, turn off the valve from the recharge line and disconnect from the low pressure service port. Good luck

Nov 04, 2009 | 1994 Chevrolet C1500

1 Answer

01 Suburban AC question

check the space between the ports, it is common to have both fittings on the same line if and only if the orifice tube is located between them because thats what seperates the low pressure side from the high pressure side, the high pressure side will be warm to hot when the a/c is running, once the hot liquid hits the orifice tube it turns into a cool vapor, so if you feel one side is hot and one side is cool then the orifice tube is whats between them and it is true that the low and high pressure sides can be on the same line.

Jun 30, 2009 | 2001 Chevrolet Suburban

2 Answers

Looking for low pressure port for servicing Freon in A/C system for 1998 Chevrolet Suburban. There are 2 ports on top of compressor. Which is the low side and which is the high side?

The ports on my 2005 silverado are on the same line,which is very confusing but, in between the two ports is the metering device (orifice) which changes the high pressure gas into a low pressure gas.The two ports are of a different size,with the low pressure being the smaller of the two. You can put your hand on the line, on each side of the metering device connection and the high side will be hot and the low side will be cold

Apr 19, 2009 | Chevrolet Suburban 1500 Cars & Trucks

1 Answer

Need to add Freon

There are two A/C service ports located somewhere in the system, one on the high side (larger port) and one on the low side (smaller port)

They are located in different areas depending on the vehicle, and there is no general location I can give you.

Start from the compressor (belt driven on the engine) and follow your lines, they should be somewhere on the A/C lines or accumulator/dryer (big aluminum canister near the firewall) and are (usually, if they were not left off) capped. Twist the caps off and inside is a "Schrader-type" valve (like the valves on tires). These are the service ports.

Just for reference, there are 2 different sizes of A/C lines on any vehicle, the small ones are the high pressure side (liquid side)(lines which get hot during operation) and the larger ones are low pressure side (vapor side) (lines which get cold during operation).

The system runs a small line from the compressor (on the engine) to the condensor (in front of the radiator), a small line from the condensor, through the orifice tube to the evaporator (inside the cab heater box) then a larger line out of the evaporator, through the accumulator/dryer, back to the compressor.

Jun 21, 2008 | 2002 Suzuki Vitara

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