No AC - Chevy and GMC Duramax Diesel Forum
2007.5 + (GMT 900) Non Powertrain--New Body Style-- Discussion 07.5 - 2010 Topics Not related to the Powertrain, interior, suspensions, body, wheels, tires, ect.

 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 06-03-2019, 03:42 PM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
No AC

I know, I know, there are lots of reasons why my AC could have went out. I have looked into it and just need some other opinions/ideas.

I replaced a line on it before winter of last year and didn't have it recharged as it was already getting cool out. Fast forward to 3 weeks ago and finally had it professionally recharged (put under vacuum, oiled, etc). It worked great up to 3 days ago. Originally from MI and am now in TX and it goes out, of course...

Two days ago it was working but the air wasn't as cold as it had been and took about 10-15 mins to blow cool, but then again I was now in the temps of 90 degrees outside and thought that maybe it was just trying to keep up. The next day I got in and turned it on and no cold air, straight hot.

Checked the compressor and it was spinning continuously, checked low-pressure side and it was at 27psi, I'm not able to check high side currently. Checked the blend door in the dash and it was operating fine. Also felt the lines coming out of the firewall, one was cool with condensation and one was warm/hot.

Not sure what else to look at. I'm no pro when it comes to HVAC, so other input would be great. Thanks!

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 06-03-2019, 04:30 PM
Senior Member
 
long-time-dmax's Avatar
 
Join Date: May 2016
Posts: 963
That makes no sense. If the compressor is running, the low side is at 27 and the evaporator is getting cold and the blend door is in the right position, it should be blowing cold air. Or at least cool air.

does that truck have a cabin air filter? My 2002 does but I think they got rid of that at some point. Wouldn't make the air hot but would drastically cut down on flow - ask me how I know.

2002 Chevy 2500HD Crew - Original owner - 404,000 miles so far. All stock with the exception of a lift pump and Donaldson filter

Last edited by long-time-dmax; 06-03-2019 at 04:33 PM.
long-time-dmax is online now  
post #3 of 9 (permalink) Old 06-03-2019, 06:06 PM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
That's what I'm saying...

It does have a cabin air filter, haven't checked it as air flow is fine. I will check it tomorrow though.

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
Sponsored Links
Advertisement
 
post #4 of 9 (permalink) Old 06-04-2019, 09:31 AM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
Ok so actually it doesn't have an air filter, so no checking that.

I did borrow a full set of gauges to measure both high and low sides and here is what I got.

ENGINE OFF
LOW - 37
HIGH - 35

ENGINE ON
LOW - 25
HIGH - 85

Sounds like low refrigerant to me? Possibly a VERY slow leak somewhere? I let it run for about 10 minutes and the numbers had changed.

LOW increased from 25 to 35
HIGH increased from 85 to 90

After shutting the engine off the readings were different from the initial as well, possibly from the system heating up.

LOW OFF was 50
HIGH OFF was 50

Hopefully someone can help decipher this. My guess is either just low on refrigerant with a leak or possibly a failing compressor. I'm going to get more refrigerant today and top it off and see what happens.

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
post #5 of 9 (permalink) Old 06-04-2019, 11:32 AM
Senior Member
 
cdub311's Avatar
 
Join Date: Aug 2015
Location: SoCal
Posts: 355
You low on refrigerant by those pressures at least 50%. You most likely have another leak and it should be fairly easy to find if it was charged the correct amount 3 weeks ago. When system is off both side should read the same, you have that but it should be almost 2x the pressure or about 90-PSI on both sides (static). After running it should be close to 50 psi (low) and 180-200 psi (high)You compressor is "on" because there is some juice in it to make the pressure switch turn on the clutch. You need to have tracer dye added to the system with a re-charge and have it inspected. Take it back to who charged it before and ask for help to find the leak. service ports like to leak and hoses.

2006 GMC LBZ CCLB PPE down pipe 5" after the cat. PPE airbox mod. ATP EFI Live DSP5. CTS 2. Air Dog 165-4G.
Leveled with Bilstien 5160 front 5100 rear. PYO wheels with 285/75/16 AT
cdub311 is offline  
post #6 of 9 (permalink) Old 06-04-2019, 01:11 PM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
Thanks, cdub311. That's what I was thinking as well. I have put dye in it and so did my mechanic in case there is a leak. I have looked around and found nothing... I'll have to take a closer look around.

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
post #7 of 9 (permalink) Old 06-04-2019, 02:29 PM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
Added one can of refrigerant and it seemed to get a bit cooler. The numbers went up to 65 on the low side, and 150 on the high. Still doesn't seem about right, as far as I know it should be about 45 on low and 200ish on the high.

I think I did find my leak though. I was looking at all the connections and on the lines... the seals on the compressor itself seem to be leaking. It looks a little wet towards the bottom of the compressor. The compressor is also SUPER hot. I just brushed it with my hand and it felt like I burnt myself on it. I think it's safe to say I need me a new one of them.

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
post #8 of 9 (permalink) Old 06-05-2019, 07:54 AM
Senior Member
 
long-time-dmax's Avatar
 
Join Date: May 2016
Posts: 963
In the 17 years I've had my truck I've had 2 freon leaks. Both times it was the high side schreader valve.

Fully charged and working properly, your pressures should be around 30ish on the low side and 270ish on the high side. Higher on the low side and lower on the high side usually means your compressor is showing signs of wear.

You could have damaged your compressor by leaving the system uncharged all winter. Your compressor WILL run when you use defrost. But yours probably didn't because there is a low pressure safety switch. My guess would be that the cylinder walls of the compressor dried out with no charge in the system and once recharged and engaged, is when any damage was done.

2002 Chevy 2500HD Crew - Original owner - 404,000 miles so far. All stock with the exception of a lift pump and Donaldson filter
long-time-dmax is online now  
post #9 of 9 (permalink) Old 06-05-2019, 07:59 AM Thread Starter
Junior Member
 
Join Date: Jul 2018
Posts: 75
Makes sense to me. Thank you for your help!

07.5 Silverado 2500HD LMM
aFe 4" exhaust turbo back
aFe CAI
Sinister Diesel EGR delete, PCV reroute and EFI Live on the fly
greatwhite93 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevy and GMC Duramax Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome