A/C Line Freezing

[johnlew37]

Any idea what would make the low pressure line such as the photo? Its hard to see but within 30 mins of running its froze solid. I then just now noticed both the low and high having a lot of condensation on them when i looked but the a/c hasnt been on.

The truck has been running hotter this week so was going to replace the water pump and theromostat, but wondering if the lines freezing has anything to do with it. Havent ran the ac at all this week. Truck stays consistent at 225-230 but if in traffic or such will get to 236 before cooling back down.

 

[crash68]

The reason why the high side line is sweating is the refrigerant sub cooler, it's where you see the smaller line tee out of the larger one.
Does the system keep cooling inside the vehicle and does this happen with the fan on high? Does the icing stop at the sub cooler or does it continue all the way up to the compressor?

 

[Daw14]

Those temperatures are high, something is causing that . Maybe the two are a fan not coming on ? That’s where I would start.

 

[markabby]

low freon?

 

[MRFREEZE57]

As long as it is cooling the inside of the cab I would not worry about it.
You may want to check to see if the evap coil is plugged with dirt and debris, that can restrict air flow and cause it to flood back.
The best thing would be put a set of gauges on it to see what is going on in the system.

 

[johnlew37]

The reason why the high side line is sweating is the refrigerant sub cooler, it's where you see the smaller line tee out of the larger one.
Does the system keep cooling inside the vehicle and does this happen with the fan on high? Does the icing stop at the sub cooler or does it continue all the way up to the compressor?

If you keep the fan on high it will cool. If you turn the fan speed down it will quickly stop blowing.

 

[johnlew37]

Those temperatures are high, something is causing that . Maybe the two are a fan not coming on ? That’s where I would start.

I am aware. The fan is turning on. Relaxed the water pump, temp sensor, fan clutch, and thermostat, and it still wants to run those temps.

 

[crash68]

Have you washed the radiator and AC condenser? check between them. Could solve both issues your having.

If you keep the fan on high it will cool. If you turn the fan speed down it will quickly stop blowing.

Taking a guess but it's possibly the expansion valve is acting up flooding the low side with too much refrigerant. Would need to take some good pressure and temperature readings to verify.
I doubt it's just an overcharge situation, but the refrigerant would need to be recovered to properly weigh in the charge, probably not much more to change the expansion valve since the refrigerant in the system is going to be recovered already.

 

[04fxdwgi]

The main culprits for the lines / coils freezing are low refrigerant gas pressure and a clogged / very dirty evap coil (inside the A/C ducting). Low air flow will also cause freezing of lines and the coil. See if cleaning evap coil will help.

That's why an air filter in duct before coil helps and, at times, hinders the whole situation. Have seen some pretty nasty coils at times, including rodent nests on them.