A/C line freezing

9 LIVES

9 LIVES

Demolition Expert
Just had a new evaporator put on my 2012 3500. Recently the A/C would run for an hour and then it would stop blowing cold air and the air would barely come out of the dash. Brought it in to my local shop that works on my trucks and he found the evaporator was 100% clogged, two year prior same issue and the first time he cleaned it and put it back in. This time he put a new evaporator in.

Fast forward 2 weeks to this weekend and me and the family were off to haul our camper into the mountains and after an hour or so....same thing A/C stops blowing cold. I pulled over and popped the hood and the large A/C line that goes into the fire wall was frozen over.

All the reading I've done says that there is two scenarios here.
1. Line is clogged (but with what? sealed system right?)
2. To much Freon in the system and it freezes the line.

Any of you guys have experience with this?
 
9 LIVES said:
Just had a new evaporator put on my 2012 3500. Recently the A/C would run for an hour and then it would stop blowing cold air and the air would barely come out of the dash. Brought it in to my local shop that works on my trucks and he found the evaporator was 100% clogged, two year prior same issue and the first time he cleaned it and put it back in. This time he put a new evaporator in.



Fast forward 2 weeks to this weekend and me and the family were off to haul our camper into the mountains and after an hour or so....same thing A/C stops blowing cold. I pulled over and popped the hood and the large A/C line that goes into the fire wall was frozen over.



All the reading I've done says that there is two scenarios here.

1. Line is clogged (but with what? sealed system right?)

2. To much Freon in the system and it freezes the line.



Any of you guys have experience with this?
Click to expand...

See if you can follow that line back to a point where it transitions from frosted to not. If that transition point is at a junction in the lines, then it's likely the orifice tube.


Loss of air flow after a period of operation is a freezing evap core. One cause could be that the sensing tube is out of position. It should be roughly in the center of the core from what I recall.

Sent from my motorola one action using Tapatalk
 
I just went through this on my 05. Same issue with freezing up where the orifice tube line enters the firewall. My symptoms were elevated temps out of the vents and only cooler (not cold) air from the driver side vents. Passenger side was warmer.
Service manual stated either low on freon or clogged orifice tube for the symptom. I threw gauges on it and low side was very low. I removed freon and pressure tested the system with nitrogen. No leaks after 2 days so I removed orifice tube line. Dumped AC flush in the line and blew out a wad of shavings and grey gunk in the reverse direction of freon flow.

Changed every component except the evaporator being it was changed 15k miles ago when dash was out. I just flushed it and the remainder lines very well.


Going on two weeks and all seems good.
 
Since you both have had “trash” reappear in the system after repairing the issue, it has to be coming from the compressor. There are no other moving parts to create “trash”.
 
So another words expect to be buying a compressor and every component that has not already been replaced
 
If the compressor fails and trashes the system you'll also be replacing what you've already replaced, too, unless you can clean them out.

The only other cause would be that at some point, someone had the system open and somehow introduced the trash into the system or the compressor failed and was replaced but the trash from the failure was left in the system.
 
You must log in or register to reply here.
Back
Top