CAT 320 CL A/C issue

[Gary Layton]

2006 CAT 320CL sn PAB06638 Engine SN MAE05872 AR No. (arrangement) 2870092

While greasing the 320 yesterday I had the engine running. I heard a loud POP noise and a hissing release of pressure...and the engine rpms increased slightly. I immediately shut down the engine and looked for any obvious leaks...none were found. Re-started the engine and noticed an "E" in the a/c panel temperature display. The "E" appears when "AUT" is engaged for the a/c system. The a/c is not cooling now. It has been very good up til now in our S. Georgia hot days here. Is there an over-pressure release on the a/c system or did a hose likely burst?

I am in the process of reaching out for a service tech to come evaluate and repair. I found a video of CAT a/c repair and it looks daunting...remove the seat to access some of the system, belly plates for other parts. I accessed the ECM (ECU?) and copied out the codes...picture attached.

I won't be trying to fix it myself...no a/c experience...but if you have info you think might be useful I am all ears.

 

[Vetech63]

E may mean empty............due to a popped hose would be my guess.

 

[heymccall]

Post #5 here

320C Air Conditioning not cool

Our 320C has been giving us some issues with the air conditioning not blow cool enough. It always has kept us cool but now its not getting the job done. I wouldn't say its blowing warm just not as cool as normal. Also the digital ac control (where you turn the temp up and down on the control...

www.heavyequipmentforums.com

 

[Gary Layton]

Thanks, heymccall...I saw that last night but have not tried it yet. I talked to 3 possible service outfits here but none do CAT A/C. I just talked to the Yancey CAT guys here and Monday (five days) is the soonest they can get to me. Looks like I'll be shut down awhile...temps in high 90s here with high humidity.

 

[heymccall]

Can't do Cat AC?
Seriously?
You are most likely dealing with refrigerant loss from a component or hose failure.
The system mechanics are identical to an automobile AC system.
Get up (in) there and look for failed hose or green staining, as the system has green dye in it.
Replace the failed part and the receiver drier and have the system evacuated and charged.

As for the "no AC experience", really? A compressor, several hoses, and two "radiators". Find the bad part and we'll walk you through it, at least enough to get someone who isn't $200/hr to finish it.

 

[Gary Layton]

The air conditioner error codes are as follows.. they are all steady, not flashing.
E 13, 14, 43, 45, 51.

I am starting to look at how to remove the seat assembly to gain better access and it looks like a mofo. I found some basic instructions in another thread on this forum and I'll see if that works.

 

[Cmark]

You really need an A/C technician to come out, pressurise the system with nitrogen and find the leak. Jumping straight in and pulling the cab apart may turn out to be a waste of time.

 

[Gary Layton]

Good input. I thought if it was simple enough I would clean up the seat and AC area (ducts, filters, whatever I could access) before the tech comes Monday. I just looked at the seat assembly again and I am rethinking...in agreement with you.

 

[ahart]

Gary, if you heard a pop sound, it was likely a high pressure line. All the high pressure lines are outside of the cab. I would start at the compressor, probably have to lower the bottom access panel below the engine to be able to see well. Follow the small line from the compressor (that’s the high pressure line) to the condenser, that’s the small aluminum radiator that you can see in front of the main radiator. From the condenser it goes to the dryer, a shiny aluminum cylinder with two hoses connected to the top, likely close to the condenser. From there it goes to an expansion valve located at the bottom of the cab, after that it’s all low pressure lines to the evaporator (which is behind your seat) and back to the compressor. You will probably be able to see which line ruptured and then you can decide how to proceed.

 

[heymccall]

Until I got my nitrogen kit, I used to pull the shraeder valve on one of the ports and blow regulated compressed air in to find leaks. Just hose clamp some fuel line from a blow tip to the port, after the valve is spun out.. The air wasn't a problem as long as I changed the receiver drier before vacuuming the system.

 

[Gary Layton]

Great input, ahart. Good descriptions. I'll look at some of those areas today without knowing exactly what I was looking at but I was tracing lines. I saw some suspect liquid but I didn't know if it was from earlier leaks on the excavator or what. I hope it's one of those reasonably easy to get to lines you're talking about. I'll use your description to check further when I get a chance. Thanks.

 

[Gary Layton]

Heymccall... My son suggested that exact procedure as a way to try to figure out where the rupture was. Looks like he was on a good thought path. Thanks.

 

[92U 3406]

Cat A/C is literally no different than anything else.

Shouldn't be hard to find the leak, head for the area you heard refrigerant escaping from and start searching. Should see fresh oil as well as UV dye if it was added.

Probably a blown hose. Not hard to replace. Replace the dryer also.

 

[gcsupraman]

Interesting....your display appears to be in Fahrenheit. I bought my machine used and it's in Celsius. I couldn't figure out how to change it and assumed it wasn't even an option

 

[ahart]

Post a serial number and we’ll see if we can help with that

 

[heymccall]

Sorta related.
Code list for most Cat AC.

 

[Cmark]

Interesting....your display appears to be in Fahrenheit. I bought my machine used and it's in Celsius. I couldn't figure out how to change it and assumed it wasn't even an option

 

[gcsupraman]

View attachment 301313

My display is a little different....but I'll hold down a combination of buttons for 5 seconds tomorrow morning and see if I get anywhere.

Thanks a bunch

 

[ahart]

On that type hold fan increase and fan decrease at the same time for 5 seconds to change from English to metric

 

[gcsupraman]

Sorta related.
Code list for most Cat AC.
View attachment 301307

This was very helpful. I had codes e45 and e51. I added some refrigerant and e51 is gone and the A/C is working again. The dealer added refrigerant a year ago so it’s slowly leaking somewhere.

E45 I’ll have to investigate at a later time. I’ll see if I can look in the parts manual to identify which damper I need to take a closer look at.

On that type hold fan increase and fan decrease at the same time for 5 seconds to change from English to metric

It worked! The machine has probably been on Celsius for 18 years. Thank you very much.