AC leak detection 2008 Chevy Suburban

[Snagglefoot]

For those who keep their cars less than 10 years the odds are good the AC system does not require work. However, I lost all my R134A refrigerant from my 14 year old Chevy Suburban . It comes from the factory with dye in the system so went over the vehicle with a black light looking for leaks. I found one at the connection to the high pressure line to the evaporator. Suburbans are notorious for getting leaks in the lines to the rear evaporator so I decided to run a can of refrigerant with dye through the system to spot any leaks along the lines.

So, with zero pressure in the system I loaded a can of refrigerant with dye in with the system set to defrost, which turns on the AC. As it went in, the compressor started to run and the low side cycled on and off between 30 and 70 psi for less than 5 minutes. The refrigerant leaked down, the compressor stopped and and the rest of the refrigerant leaked off.

Now before anyone accuses me of leaking off R134A, I’m in Canada, where we can use R12A which is a mixture of propane and Iso-butane. It’s not regulated for re-capture and is not considered Ozone depleting. I went over the entire vehicle, including the AC lines to the back and I couldn’t find any additional leaks.

Here are two photos. The first one is when I spotted the factory dye and the second shows additional dye that got sprayed onto the high pressure line from the bad connection. Enjoy.

 

[Fitter30]

That is big leak. Always pressurized a system with nitrogen and use soap bubbles for another check. Probably want to change all seals that are easily accessible and another pressure test.

 

[Snagglefoot]

Here is the R12A refrigerant with dye and the loading hose for vehicles originally equipped with R134A.

 

[Snagglefoot]

Here's “ The rest of the story “ for whoever is interested. The only place I found the dye was where the high pressure line went into the evaporater. I took the line apart, which coincidently let me access the orifice tube. I put in a new tube. I then removed the accumulator and put a new one in, replaced all the associated seals with new ones, pulled a vacuum to 30 in hg for an hour, then loaded it with R12A. I also replaced the low pressure sensor which for some reason did not check out.

I tested the system with my truck parked in my heated garage and the AC automatically comes on with the defroster as per the factory design.

I’ll wait until summer to see how it functions on a hot day. Thanks for reading the post.