AC DIYs Step In

jrob56 · April 22, 2019

Hello All,

2014 Silvy and no AC, I have read all this forum seems to offer. My system is so low I couldn't just get dye in to confirm the leak, compressor wouldnt kick on. Im going to pull a vacuum to confirm the leak, then charge it that way since the vacuum should get me a jump start on getting the system to take refrigerant. Then find the dye with a light, I suspect condenser, but want to confirm before buying the part.

Question for those of you who have done this. Did you add oil on this initial charge to get dye in, to protect the compressor? Or did you only add oil in after the fix on the final charge? If so, how much did you add each time. I've read 2 oz for a compressor replacement, but not how much for a condenser.

Thanks,

Josh

1SLOW1500 · April 22, 2019

Sound like you dont have the gm recall lines and support?

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randy.channell · April 22, 2019

Did they recall? I've got a 2014 5.3 Sierra with the same issue.

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1SLOW1500 · April 22, 2019

Yes it was not a recall as much of a service bulletins. Sorry. But yes the new line is reinforced with plastic split loom and then there is a bracket that clamps on to reduce vibration. Cheap parts and easy swap. No reason not to do it.

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Snowcamo · April 23, 2019

3 hours ago, jrob56 said:

Hello All,

2014 Silvy and no AC, I have read all this forum seems to offer. My system is so low I couldn't just get dye in to confirm the leak, compressor wouldnt kick on. Im going to pull a vacuum to confirm the leak, then charge it that way since the vacuum should get me a jump start on getting the system to take refrigerant. Then find the dye with a light, I suspect condenser, but want to confirm before buying the part.

Question for those of you who have done this. Did you add oil on this initial charge to get dye in, to protect the compressor? Or did you only add oil in after the fix on the final charge? If so, how much did you add each time. I've read 2 oz for a compressor replacement, but not how much for a condenser.

Thanks,

Josh

I am an HVACR tech by trade. I can tell you you will be chasing ghost trying to confirm a leak on any auto ac by pulling a vacuum. This is mainly because the compressor front seal is not meant to handle a vacuum. The best practice is to use nitrogen and a leak detector of some sort be it soap bubbles or an electronic leak detector. I use both. You can heat up the refridgerant cans in hot water. In the field we use our torches, but we watch our bottle pressure on our gauges so the cans or jugs wont blow. Automotove standard epa 608 is only zero psi for vacuum while everything else hvac related is 500 microns well beyond -29. Pull your best vacuum 30 to 1hr. Connect your leak detecktor can and let the vacuum pull it in. Once done charge the rest of the way. Max ac full blast windows down. Heat your cans as needed.

jrob56 · April 23, 2019

2 hours ago, 1SLOW1500 said:

Sound like you dont have the gm recall lines and support?

Sent from my SM-N960U using Tapatalk

Correct, no recall on the pickups. Im out of warranty except powertrain so not going to try and fight with dealers. Easy enough to swap parts and relatively cheap compared to the 1000+ Ive seen. Even the 99 fee to diagnose or whatever they charge to charge system is about what parts will cost me.

I will be inspecting this line as well and adding the bracket regardless I think. Seems these fixes are evolving though. Thought I read there was an updated line as well, not just the bracket anymore.

jrob56 · April 23, 2019

Just now, Snowcamo said:

I am an HVACR tech by trade. I can tell you you will be chasing ghost trying to confirm a leak on any auto ac by pulling a vacuum. This is mainly because the compressor front seal is not meant to handle a vacuum. The best practice is to use nitrogen and a leak detector of some sort be it soap bubbles or an electronic leak detector. I use both. You can heat up the refridgerant cans in hot water. In the field we use our torches, but we watch our bottle pressure on our gauges so the cans or jugs wont blow. Automotove standard epa 608 is only zero psi for vacuum while everything else hvac related is 500 microns well beyond -29. Pull your best vacuum 30 to 1hr. Connect your leak detecktor can and let the vacuum pull it in. Once done charge the rest of the way. Max ac full blast windows down. Heat your cans as needed.

Thank you, exactly what I was going for. I saw it hold steady at -24 ish and leaked down to -22 after an hour or so, but hardly definitive. It was enough to jump start the recharge though, put a can with dye in and clutch started up. With AC on max I was sitting at about 26-27 low and 150ish high maybe a tad lower(going off memory). These pressures sound okay? Going to get under tomorrow with the light and give it a once over.

Snowcamo · April 23, 2019

https://images.app.goo.gl/L68sLgeznLTPdT8t9

Looking at the pressure= temp chart your right at freezing temps in the evaporator. Typically for compfort cooling we like to see a 40°F evap temp. That would put you at 35 psi on the low side. The pressure will rise as the heat load is increased. Looks like these trucks hold 21.16 ounces. As long as your there id just let it roll. Wait till it gets in the 80°F range out and go from there. And check for leaks along the way.

Bash74 · April 23, 2019

You could have a bad condenser. The condenser was another problem the trucks had.

Hillwood · April 23, 2019

13 hours ago, jrob56 said:

Hello All,

2014 Silvy and no AC, I have read all this forum seems to offer. My system is so low I couldn't just get dye in to confirm the leak, compressor wouldnt kick on. Im going to pull a vacuum to confirm the leak, then charge it that way since the vacuum should get me a jump start on getting the system to take refrigerant. Then find the dye with a light, I suspect condenser, but want to confirm before buying the part.

Question for those of you who have done this. Did you add oil on this initial charge to get dye in, to protect the compressor? Or did you only add oil in after the fix on the final charge? If so, how much did you add each time. I've read 2 oz for a compressor replacement, but not how much for a condenser.

Thanks,

Josh

Hey Josh, The system comes from the factory with dye in it. You don't need to add any.

ksiesel · April 23, 2019

From what I can tell, the support bracket was released as a bulletin back around 2016. I looked at my 2018 this morning and I do NOT have the support bracket. I do have the reinforced line with the split loom though.

The 2017 and 2018 models have a slightly different setup though (likely due to the use of R1234yf instead of the R134a). Do the models with the new refrigerant still need the support bracket?

jrob56 · April 23, 2019

Bingo, but not a prize I wanted to win! Gotta check the lower line still. All looks good from up top.

Edited April 23, 2019 by jrob56

jrob56 · April 23, 2019

Lines look good but no bracket. It’s a14 and never been in for this so not surprised. No leaks so would be preventative. Anyone know the current part number for that?