NEED HELP AC not blowing cold air, possible freon leak

Chuck1906

Original poster
Member
Sep 10, 2016
5
Delaware
Thinking I was low on freon, I bought a can of 134A and added some freon to my system. My AC was still blowing warm air out. Three weeks ago, I took my SS to the dealership and they charged me $160 to recharge my AC system which included adding freon with a special dye to detect leaks. That worked 2 days then went back to having warm air blowing out. The next week, I took it back to the dealership and they recharged the AC system again and said my freon was low so they added some more. The cold air lasted for about 1 week then the passenger side was blowing cool but not cold air and the driver side was blowing warm air. This made me think maybe its a motorized blend door issue behind the dashboard. Last week blower motor died! I had the AC controls on full blast and nothing was coming out! Back to the dealership I go last week where they charged me $260 to replace the blower motor. They added more freon and the mechanic said it was blowing cool but not cold air! Two days later I am back to square one with the thing blowing warm air on both sides of the truck! There is an obvious leak somewhere in the system.

I am at a loss of words right now! I've taken my truck to the dealership 3 times in the last 3 weeks and they can't get this right!

Has anyone experienced anything like this? They claim the dye they used to detect a leak, they cannot locate where the leak is. However on the invoice of my latest dealership visit, they made a note and said its most likely an evaporator leaking inside the case. They also said they found voltage and ground going in to the fan motor resistor but no ground coming out to motor. They removed and replaced the blower fan motor resistor which they had to rewire because its an updated part. They charged the system up to 1.87 pound. Two days later its back to blowing warm air again! Smh!

Thoughts or suggestions?
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
:tiphat: Welcome to the forum!

I had a similar issue with a leak about a month ago... Well I finally fixed it a month ago, had been on going for some time. I feared it might be the evaporator core as well, because when I added die, and looked everywhere with a UV flashlight, I couldn't find any dye anywhere.

Turns out, when I added some refrigerant (and also when I pulled a vacuum) I could hear a hissing sound from the accumulator, next to the coolant overflow reservoir. It had some sort of internal leak, that didn't allow the dye to reach the exterior where I could see it. I ended up replacing that, MUCH cheaper and easier to get to, and that solved my problem. Added some oil and recharged the system with 3 cans of refrigerant (I have an EXT), and have been good ever since. :twocents:

20160726_193013.jpg
 
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Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
When I was fearing my evaporator core might be the issue, I looked into the removal procedure (just to see if there was any dye on it) and it was a bit intimidating, so I took my truck to a shop to diagnose it for me. They were able to check it for a leak without removing it, and told me it was OK. I think that dealership has seen you come in a few times, and has you pegged as someone they might be able to get a lot of money out of. I'd say keep your distance, if you don't feel up to doing the job yourself, maybe go to an AC shop instead.

BUT, if you have money to burn like that, you can PayPal it to me, so it can go to a good cause :biggrin:
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Mine leaked somewhere I couldn't find neither at the time and I had to buy a leak detector. It confirmed that my evaporator was bad. Took a whole day to rip out the dash to replace it but it's been fine since.
 

mrrsm

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Supporting Donor
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Oct 22, 2015
7,639
Tampa Bay Area
If you are intent upon doing this Investigative Repair yourself... using NYLOG may turn out to be your Best Friend to solve microscopic refrigerant leaks at each and every Hose<->O-Ring<->Flange contact locations:

https://www.amazon.com/dp/B008HOSQQQ/?tag=gmtnation-20

31dN%2BO9TAeL.jpg

 
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Texan

Member
Jan 14, 2014
622
FWIW: My 03 TBLT with 139k miles, after 13 years had a Freon
leak in the HP line from the condenser to evaporator. Had to remove
air filter box to find the leak with dye.
 

mrrsm

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Oct 22, 2015
7,639
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The BLUE flavour of NYLOG is for systems that are Alkyl-Benzene based and use PAG or Poly-Alkyl-Glycol Lubricants...so Automotive R-134A requires the BLUE flavour and NOT the RED....an important distinction worth mentioning here...for sure.

About the eBAy S&H FUBAR... for anybody that gets stuck on this ...send the Seller a message that you want to to cancel the order or to fix "The Typo" so you can complete your purchase... This is what happens when eBay Sellers mistake their Vodka Bottles for their Orange Juice in the morning.
 
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Chuck1906

Original poster
Member
Sep 10, 2016
5
Delaware
When I was fearing my evaporator core might be the issue, I looked into the removal procedure (just to see if there was any dye on it) and it was a bit intimidating, so I took my truck to a shop to diagnose it for me. They were able to check it for a leak without removing it, and told me it was OK. I think that dealership has seen you come in a few times, and has you pegged as someone they might be able to get a lot of money out of. I'd say keep your distance, if you don't feel up to doing the job yourself, maybe go to an AC shop instead.

BUT, if you have money to burn like that, you can PayPal it to me, so it can go to a good cause :biggrin:

LOL! Well the second time I went back they didn't charge me to recharge the system again but I had to pay the third time because the blower motor had died. Now after working 2 days, I am back to having warm air being blown out! I am going to look into the suggestions you mentioned and hope that works in my situation. Nope I don't have money to burn for this nonsense, I'll have to either do it myself or take it to a friend and have them do the install! LOL!
 

mrrsm

Lifetime VIP Donor
Supporting Donor
Member
Oct 22, 2015
7,639
Tampa Bay Area
@Mooseman nailed it by suggesting a Trace Amount Refrigerant Leak Detector like this inexpensive one offered on eBay. THIS $20.00 Tool will make quick work of finding ANY leaks... just remember NOT to test it by holding the sensor end directly into a pure stream of Refrigerant...or it will instantly burn out the sensor mechanism:

http://rover.ebay.com/rover/1/711-5...0001&campid=5338077216&icep_item=311590878150


s-l1600.jpg


Again...if your intention is to attempt this repair... please look over my "Alter Ego" "Baker's Dozen" How-To Post I wrote long ago over at www.60degreev6.com to act as a Primer and Guide on pretty much every Step-By-Step necessary to solve this often intractable problem:

Air Conditioning System Replacement Tips

  • by
    60dgrzbelow0
    Published on 07-26-2010 03:48 PM
    0 Comments
    comment.png

    This kind of repair involves more than just an R&R of a damaged compressor, since the old refrigerant must be removed from the system and stored in a proper container. Also... once the new compressor is installed, the system MUST have a near perfect vacuum established or the A/C will not ever cool properly. To avoid any woes (Whoas!) for your A/C repair, here are some suggestions for the fix that are "The Universal Baker's Dozen of Auto A/C Repair" :

    1. Change the Accumulator and Orifice Tube (or TXV -Thermostatic Expansion Valve if so equipped) at the same time the Compressor is swapped out. The reason is because the PAG oil that lubricates the system passes through the accumulator along with the return line refrigerant vapour and nested deep inside of the aluminum canister should be a packet of Silica Gel that acts as a hygroscopic sponge to absorb any traces of moisture/water vapor. As soon as you open any A/C system... ambient air loaded with water vapor will migrate not only into the Silica Gel pack,,, but the PAG oil will also sop or sponge up all the available moisture by literally yanking it out of the exposed air. In short...any moisture not captured by a bone dry accumulator will freeze somewhere down in the lines and plug everything up with ice.

    2. If you are NOT going to flush the A/C lines with the old compressor removed to flush out any residual dirt or metal particles from a FUBAR'd compressor... just cap all the lines as soon as you loosen and remove them to prevent the introduction of atmospheric air and non-condensable gases. Don't flush the A/C with the old compressor installed... all you will wind up doing is forcing more of any left over metal mung from inside the busted compressor deeper inside the liquid and vapor lines and have that crap lodge inside the evaporator coils and condensing coils units. Take the time and modest expense of flushing the lines of all this junk and the system will work better and get much cold(er).

    3. Replace the pale green "O"Rings on all fittings with those of an exact thickness and diameter. If you use the ones that come from Autozone...there might be enough variation for them NOT to seal ...since they tend to be thinner and less "beefy" than the factory ones. You can use the old ones in a pinch as long as they show no signs from pressure erosion, wear or tearing. Just clean the interfaces between the hose piping fittings and lightly lube them with some fresh PAG oil. Be sure to recap your bottle of PAG oil...or it will be useless in twenty minutes from water saturation if left open to the air. Go light on the torque...these aluminum fittings and hosing are very touchy to accidental damage...its the "O"Rings that do the sealing... not excessive pressure on them from their fittings.

    4. Before you install the new compressor... follow the manufacturer's recommended amount of PAG oil to be poured in. As a general rule of thumb... You should pour two (2) ounces inside the compressor and two (2) ounces inside the new accumulator...and sometimes it calls for two (2) more ounces to be poured inside the top of the condensing coil before the A/C Vapour Return Line is buttoned up at the top of the condenser coil.

    5. *** It is very important to make sure you HAND TURN THE COMPRESSOR BEFORE INSTALLING THE PULLEY/SERPENTINE BELT(S) AT LEAST TEN (10) COMPLETE REVOLUTIONS, This will cycle the PAG Oil properly, correctly distribute the lubricant and prevent the compressor from hydro-locking. Then just install the Serpentine or V-Belt(s) and prepare to vacuum down the system. This is all done AFTER you attach the A/C hose manifold just after the compressor is bolted properly in place. A flash-light, mirror and 3/8" drive with long extensions will also help you down there, too.

    6. It is worth it to head over to Harbour Freight and buy a 2.5 - 3 CFPM Vacuum Pump for around $150.00... If you own more than one car with A/C problems... fixing them yourself will surely recoup the $$$ with this item on hand. The important thing about the pump is that it be of the scroll design and be able to pull a double vacuum down to about 25 microns. It Is more important to use the most refined Vacuum Pump Oil that you can buy (about $7.00-$10.00 a quart and available via eBay) than it is to have a super-expensive unit like a Robinair or a Yellow Jacket Vacuum Pump pulling 6 CFPM). Harbor Freight also sells an inexpensive set of Auto Refrigerant Gauge Manifolds with all three pressure lines and High/Lo quick connectors, too.

    7. After the proper vacuum period... anywhere from 30 minutes to a few hours depending upon how long and how open the system was prior to this repair... then its time to introduce the R-134A refrigerant into the clean and vacuumed system. This coolant should only be put into the system through the LOW SIDE (BLUE FITTING) LARGE CALIBER ALUMINUM LINE. NEVER install the gas from a can by just turning it upside down and allowing it into the LOW SIDE as a LIQUID! And likewise...NEVER allow either refrigerant vapor or liquid to be filled on the HIGH SIDE SMALLER CALIBER LIQUID LINE (RED FITTING). People have been killed when trying this and holding a can that exploded in their face because of excessive high pressures involved during compression. Only charge R-134A on the LOW SIDE fitting!

    8. Don't be too macho about not wearing eye protection and heavy leather gloves while charging the system. If the lines or can should leak, burst or break and this super-cooled liquid splashes in your eyes or on your hands and arms...it will instantly freeze and permanently destroy those tissues. Be Careful With This Stuff!

    9. After a proper vacuum of the system... With the engine OFF.... If you are not using your own A/C Manifold Gauge Set... Then use the type of service unit that comes with a built-in hand-squeeze control valve and its own Pressure Gauge to screw into the top of your various cans of R-134A and use the short hose Quick Connector valve and attach it to the LOW SIDE (BLUE) A/C Service Valve. Tighten down the connector. Then, start the engine at idle and turn on the A/C settings to HIGH COOL with the air blower set on HIGH. Slip an inexpensive analog A/C Thermometer inside one of the center vents to measure the temperature drop.

    10. Don't be alarmed if the A/C compressor clutch does not instantly cycle on ...With the engine turned off, you will have to allow at least one can of R-134A to get inside the system and distribute itself for ten minutes or so. Then start the car and see if the LOW PRESSURE CUT OFF VALVE goes into détente and allows the compressor to engage with the electromagnetic clutch. With enough R-134A to get the pressure up, it will cycle on and off rapidly until there is enough coolant in the system to keep the clutch running continuously. As the freon gas is going into the LOW SIDE LINE service valve... move the can from the 12:00 to 3:00 position and shake it gently to stimulate the liquid to vaporize sooner and enter the system. DON'T BE TEMPTED TO RUSH THIS PROCESS BY TURNING THE CAN UPSIDE DOWN... If you do this...you could "SLUG" the compressor and damage it badly since the COMPRESSOR IS DESIGNED TO COMPRESS VAPOR...AND ALL LIQUIDS ARE INCOMPRESSIBLE!!!

    11. Allow the system to normalize for three to five minutes after each injection of R-134A and prop the can/hose into the upright position if you are SOLO when checking the thermometer and feeling for changes in the interior of the car with all windows closed. AVOID PUTTING IN TOO MUCH REFRIGERANT! R-134A does not cool as efficiently as R-12 used to and Autozone sells a small yellow container of extra PAG Oil and a "Freeze Helper" that can make a big difference. This small can of stuff goes in EXACTLY like the regular cans of R-134A and at the very same LOW SIDE PORT (BLUE)

    12. If you have to resort to using the small can of Special Sealer to stop any leaks that happen afterward, MAKE CERTAIN TO IMMEDIATELY PUT THE R-134A CHARGING HOSE RIGHT BACK ON AND PUMP SOME MORE FREON THROUGH THE SERVICE VALVE OR THE SEALER WILL PERMANENTLY PLUG UP THE SERVICE PORT!

    13. KEEP YOUR COOL...and lay out your tools, parts and lubricants in an organized way and This job... will be a "COOL BREEZE!" Remember to Wash your hands and do NOT get any PAG OIL on your Skin or in your Eyes. This stuff is very irritating to them.... and with all that said....Best of Luck!
    smile.png
 
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Chuck1906

Original poster
Member
Sep 10, 2016
5
Delaware
The part that you replaced, is that the part that is on the bottom of the part where you add more freon?
:tiphat: Welcome to the forum!

I had a similar issue with a leak about a month ago... Well I finally fixed it a month ago, had been on going for some time. I feared it might be the evaporator core as well, because when I added die, and looked everywhere with a UV flashlight, I couldn't find any dye anywhere.

Turns out, when I added some refrigerant (and also when I pulled a vacuum) I could hear a hissing sound from the accumulator, next to the coolant overflow reservoir. It had some sort of internal leak, that didn't allow the dye to reach the exterior where I could see it. I ended up replacing that, MUCH cheaper and easier to get to, and that solved my problem. Added some oil and recharged the system with 3 cans of refrigerant (I have an EXT), and have been good ever since. :twocents:

20160726_193013.jpg

The accumulator that you replaced, is that the black piece that sits under the part you connect a can of 134A too add more freon?
 
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Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
The black part is just a rubber cover, the accumulator is the unit that sits inside it. The AC pressure switch screws into it, the low pressure test port (where you add refrigerant) is on it, and there's a hose that leads from it to the firewall that has to be disconnected.
 

mrrsm

Lifetime VIP Donor
Supporting Donor
Member
Oct 22, 2015
7,639
Tampa Bay Area
Sorry that you've wasted so much money, best advice I can give you is to learn as much as you can from YouTube videos and live on this forum and you can save a lot of money doing stuff yourself

Absolutely Right..!

Here is one of our very own Members going by the Youtube Alias of "CHRISFIX" demonstrating how he recharges an Auto AC System:


And One Man is a REAL Stand-Out for anybody wanting to learn EVERYTHING you could ever want to know about the Fundamentals of HVAC Repairs. Here is a Guy who not only LOOKS like the Actor... Jeff Daniels... But he SOUNDS just like him, too. His friendly, funny and very affable approach to teaching using his thoughtful videos are easy to follow and will get you everything you need to have answered in plain English. He has videos at the below listed link that deal with All Three Areas of HVAC... Commercial... Residential... and Automotive... so enjoy watching Dr. Zarkloff:

"Hello... My Viewers..."

https://www.youtube.com/user/DrZarkloff


These are images of an Older Model 2002 Trailblazer OEM Delphi Accumulator that has both the Flexible Low Pressure Vapour Line, with the Service Schrader Valve one side (Covered with the Black Plastic Screw-On Cap) ...and the Low Pressure Sensor Port on the Opposite side. Inside this Tank dwells only a tube that the vapour enters near the bottom and an Exit Port Tube closer to the top to more or less ensure that Only Vapour will move further down the line towards the A/C Compressor.

The Aluminum Tank acts as a Temporary "Fish Bowl" to hold on to any Liquid Refrigerant that "Accumulates"... just long enough for it to be drawn outwards as a Superheated Vapour. And way down inside of it is a Silica Gel Packet resting there to absorb any Liquid Water Droplets or Water Vapour and trap it before it can migrate with the PAG Oil down inside the Evaporator and FUBAR things by Freezing Over.

These items may come with some variation and the only difference between @Blckshdw 's Brand New One and this Old One...is that the Black Insulating Boot this one used to be inside of... remained in the TB with a Brand New Delphi OEM Replacement Accumulator:DSC07247.jpg DSC07248.jpg DSC07249.jpg DSC07250.jpg DSC07251.jpg DSC07252.jpg

 
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HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Finally got down to the bottom of my issue. Apparently the AC Condenser Unit is bad!

Nice to know you got it figured and thanks for following up on here for future reference to others!
 
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