A/C Recharge Kits

[Up And Down]

So turned in the air conditioner in my 2005 TB LT SWB today for the first time this year and it wasn’t as cold as I remembered it being. Now this truck has always had the lazy AC since new, meaning that it takes a bit to get cold when you first start it up especially at idle. This was different though. It never really got ice cold. It got very cool after driving a while but never cold like I remember it being. I know an AC system is supposed to be 100% sealed and should technically never lose any of its charge, but is it reasonable that after 15 years there is a small cumulative amount of loss that is affecting performance? If I do in fact have a pinhole leak that is so small that it needs a topping off every year or 2 then it’s probably smart I just do that rather than replace parts on it at this point. Has anyone used any of the home AC recharge kits that I see available at the parts stores? The ones I’ve seen have a gauge built into them. I would prefer one with no stop leak additive in it as I have read the substances they use can clog the system and cause more problems. Any certain brands preferred? Any tips or tricks? I have no experience with AC systems and am hoping my charge is just slightly low. Thanks for any help.

 

[Mooseman]

Do not use stop leak. It will cause something known as black death.

To be able to properly diagnose what is going on with your A/C, you would need a gauge set (~$50 at HF/Amazon). Although most of those kits have a cheap gauge, it's only for the low side. You would need high side readings to be able to see what is really going on.

One possibility for the low performance is a defective fan clutch. Check it out here:

How to test the electro-viscous fan clutch

If the fan checks out, one symptom of low refrigerant is the compressor cycling on/off often.

As far as leaks, you could try and locate them using a UV light. Another way is a gas leak detector (~$50 HF/Amazom) but if the leak is too small, it may not pick it up.

 

[JerryIrons]

the ac gauge kit is really the way to go, that way you can add refrigerant without having to worry about overfilling, which is bad also. Just be aware that the high side of ac has over 350 psi, and ac refrigerant so it is to be respected when working on it.

If it were my vehicle
- buy ac gauge kit from harbor freight
if low refrigerant
- buy can of refrigerant with uv dye
- buy uv light from harbor freight ( in same section as ac stuff)
- put can in system, drive a few days, then check at night, then you can decide.

The cost of this stuff is pretty much paid for, compared to one trip to a mechanic. Especially mechanics who go by the book and are required to discharge a system if a leak is found, this is why I learned how to fix my own ac.

Now, you can go the route of adding a can with the low pressure gauge, but usually small leaks turn into bigger leaks. And the "stop leak" is terrible, it may stop a leak but will end up causing more damage to hundreds of dollars of parts in the end. It plugs up small spaces, good ones as well as bad ones.

 

[Up And Down]

Thanks for the replies. The truck is $15 years old so I don’t want to go crazy with ‘‘tis I was just hoping for a quick band aid. The fan clutch is new as of about a month ago. It does roar on startup and then subsides after I start driving. Maybe the fact that the new clutch is working and the old one wasn’t is contributing to my lessened AC performance. As far as the home recharge kits With built on gauges go, are there any that do NOT Contain a sealant of some type? All of the ones I’ve seen have it. Thanks again.

 

[TJBaker57]

Another option for seeing the high pressure side is a cheap elm327 clone OBD2 scanner and Torque or OBD Fusion App. Also the 15 or 20 bucks spent here can be useful for a whole host of other troubleshooting tasks instead of a single task seldom done.

 

[TJBaker57]

This from OBD Fusion. Also can use Torque App

 

[TJBaker57]

And yes....you can find recharge sets without additives I believe. A cautionary note here....too much refrigerant is far worse than too little.

 

[Up And Down]

Thanks TJBaker. I have access to a snap on solus pro although it’s only updated to around 2009 or 2010. I never thought an item like this would be something read by a scan tool. Does anyone know of this tool will read AC pressures?

 

[TJBaker57]

I am not familiar with the Solus. A quick look at a user manual didn't help much. The PID is GM specific so unless manufacturer specific data is available there I doubt the Solus would list it.