13 CASCADIA A/C NOT WORKING BUT COMPRESSOR ENGAGES

Hello,

First off truck is a 2013 Freightliner CASCADIA with a sleeper. I cannot figure out why I wont get cold air from the truck. Compressor was installed about 6 months ago with a new dryer. Everything worked fine then developed a leak a couple of weeks later on one of the hoses that lead to the condenser. I replaced that had system recharged but it did not work. As it was cooler weather I did not pursue problem and left as is during winter.

I spent so much servicing my trucks I bought an ac recovery machine and just started trying to get it going. Evacuated everything tested for leaks and it held pressure. So I filled it up. No cold air. Figured might be the Expansion valve so I switched the one by the firewall. Vacuumed refilled still no ac. The compressor does engage but I don’t think any of the Freon is circulating. The low pressure side hose where you fill does not get cold. The high pressure side does get cold all the way to the condenser. When the compressor engages it never cycles off and the engine fan never turns on. I do have a Manual switch and tried turning it on see if it would help but still no cold air. Dealership told me it took 3.25lb of Freon that’s what I did the first time. Second time tried 4 lb as I saw that as common for these trucks neither worked. No matter the amount of Freon I put since it doesn’t circulate the pressure I show on the low side is 75 and on the high side around 70. I have no leaks I don’t know where else to look last thing I can think of is the expansion valve under the cab for the bunk. (Bunk doesn’t blow cold either).
Any idea why the compressor engages but does not cycle the Freon? Could it be the evaporator coils? I have also tried resetting the ac system by pressing the ac buttons and it does it I hear the system doing its thing but still no cold air. Is there a possibility that a line is clogged? I am at a loss right now and have tried everything. Will appreciate any advice or ideas. Thank you.

 

Thank you for the reply. It’s definitely engaging. Turn the ac button off and it stops spinning and when I flip it on it begins to spin. Refrigerant is R134. I’ve done ac work plenty of times. Usually can find the problem but compressor seems to be working correctly I just feel as if the refrigerant is stuck somewhere. It does not circulate thru out the entire system. I’m going to replace the dryer today see if that helps when I do that I’ll disconnect every line and see if there is any obstruction. I am out of ideas.

 

That is extremely helpful! Thank you for that.

 

Just wanted to update. I didn’t want to risk doing the job more than once so I went ahead and replaced the dryer and compressor vacuumed and filled it up. Ac blew cold after. I’m not sure what was the culprit. I’m pretty sure it was the dryer because the compressor did engage. I’m just glad it’s all working now. Thanks for your help and your diagrams they gave me a better understanding.