Air Conditioning Inop

Spurshot · March 13, 2017

I drove my truck yesterday and needed the AC as it was 85F here. I was getting no cool air.

Today, I put gauges on it and got 0 pressures. I dumped a can into it and pressures didn't come up.

Checked the compressor. It (clutch center snout) turns freely. Too freely. Like put one finger on the face and turn it. Checked it against my Camaro. It takes a grasp of the clutch snout to rotate it.

Opened the system at the firewall/orfice. Clean oil and no debris (whew).

Put the vacuum pump on it for an hour, isolated it and it crashed to ambient in a couple minutes.

I'm thinking broken shaft inside the compressor.

Ideas?

bdbake01 · March 13, 2017

Check for a cracked line just outside of the compressor in the tight bend. There's a TSB out there. If you have a '14 or an early-ish '15 and you don't have a brace between the compressor supply and return lines, it's very likely. On a related note, guess what happened to me last week!

Spurshot · March 13, 2017

Check for a cracked line just outside of the compressor in the tight bend. There's a TSB out there. If you have a '14 or an early-ish '15 and you don't have a brace between the compressor supply and return lines, it's very likely. On a related note, guess what happened to me last week!

Thanks, I'll check for that.

Can you do me a favor? Try to turn the compressor by hand. Just the front of the clutch. Mine just doesn't have any resistance. Feels like the shaft isn't connected to anything.

O_J_Simpson · March 13, 2017

Well known issue. GM will good will warranty it if you ask nicely.

Spurshot · March 13, 2017

I saw a YouTube that showed a clamp/bracket that tied the hard lines for the discharge (high side) to the suction (low side) together as they come off of the compressor. None of the online parts diagrams show the new clamp.

Anyone have the new clamp part number? How about a TSB for this problem?

Dnt · March 13, 2017

http://www.gm-trucks.com/forums/topic/176517-ac-line-bracket/

Spurshot · March 14, 2017

Can I impose on someone, maybe a few of you, to reach down and try to turn the front part of your compressor clutch?

Mine just seems completely disconnected from any internal parts. Like it was a sheared shaft. I can put one finger on the front of the snout and turn it.

bdbake01 · March 14, 2017

Can I impose on someone, maybe a few of you, to reach down and try to turn the front part of your compressor clutch?

Mine just seems completely disconnected from any internal parts. Like it was a sheared shaft. I can put one finger on the front of the snout and turn it.

Sorry, been out of digital range all day. Mine spins free. Just a tad bit of resistance. But line is visibly cracked. It's a hellacious spot to get to or I'd take pics. Also, it's cold

Spurshot · March 14, 2017

I looked at the lines as closely as possible with a mirror and strong light. I couldn't find cracks.

I'll pull the lines and inspect them out of the truck. But I'm just going to order a set of lines anyway.

bdbake01 · March 14, 2017

I looked at the lines as closely as possible with a mirror and strong light. I couldn't find cracks.

I'll pull the lines and inspect them out of the truck. But I'm just going to order a set of lines anyway.

Just a quick pressure check will tell you if you have bad lines. But if you don't have the brace, it's good money to replace anyways.

Spurshot · March 14, 2017

I vacuumed the system. It wouldn't hold a vacuum. I'm a bit worried it could be a condensor or the compressor.

Spurshot · March 15, 2017

I removed the compressor, all the lines, and inspected all of it. I don't see any cracks or indications of leaks.

I'm thinking maybe it's the condenser. I have to figure a way to leak check it, preferably in the mounted position. I'm thinking vacuum check it.

silveradosid · March 15, 2017

i would use pressure to check it, even the best gauges can have small vacuum leaks. i use an inline reciever dryer half full with oil and pressurize the system with 150 lbs shop air, most times you will hear the leak, i also put leak detection dye in every system after repairs are done

Leo0916 · April 22, 2018

What did the problem end up being? I am having the same issue.

JimCost2014 · April 25, 2018

On ‎4‎/‎21‎/‎2018 at 8:12 PM, Leo0916 said:

What did the problem end up being? I am having the same issue.

Wife is going to take our 16 Tahoe in under GM special warranty 17336-02 for the AC not working. Not sure if this TSB is for the trucks also or not, does not hurt to ask. On the SUV's it extends the factory warranty to 5 years or 60000 miles for this issue.