I'm hoping to fix my A/C system myself if possible; I've heard horror stories of the huge amount shops charge to do it, and as my air blows cold when the system is fully charged, I'm hoping its simply a leak or something simple to fix. I don't have any experience though, so I have a few questions.

1. How are lines typically sealed in an A/C system? I happened to notice that the area around where a steel line bolts onto the compressor feels really sticky, so I suspect this may be my major leak point (or at least one of them). I know the system is highly pressurized, so is there a special kind of sealant that needs to be placed between where the lines connect? Is there a certain torque specification for that spot that I need to check, or just tighten it down more?

2. When the system is charged, my Blazer bogs WAY down at take-off, even with the A/C turned off. I have to hold the pedal to the floor just to get moving on a level road. The motor doesn't try to die; its kind of like its trying to take off in too high of a gear. I don't know how the A/C could affect the transmission, but thats exactly how it acts. After the system has leaked completely out (its no longer capable of blowing cold air and the compressor won't even cycle), the Blazer goes back to driving normal. Any ideas on what could cause that?

I appreciate any tips I can get!

 

The ac system does require some special tools to take it apart and service it. I am sure you cohld find a general how to on the net. As far as discharging the system "you should do it properly" but if one of your lines became "loose" it would "accidently" discharge the system...would back away to avoid inhaling that...
As far as performance and ac...it shouldnt....the worst i would think could happen is that your compressor locks up and destroys your serp belt.

Hope that helps

 

Thats my point though; that IS what its doing, and I can't figure out why. I've recharged the system twice and thats what happened each time. Performance goes back to normal after the system has completely leaked out (it takes about a week to stop blowing cold, and two weeks to empty so that the compressor won't cycle). I wonder if it could be too little oil in the system, causing the compressor to struggle harder and bog down the motor? It wouldn't quite lock up, but might take more power to turn from the motor. I still don't know why that would affect it when the A/C is off and the compressor clutch is disengaged though.

Seriously, it literally NEVER does this unless I've charged up the system. I've recharged it twice in the past two years, and its done it both times. The system empties itself, so I probably won't have a lot to worry about with having the refrigerant recovered.

 

Do we know if the compressor is still good? I've had bogging in other vehicles with leaks, but tracked it down to a compressor issue. That would put a drain on the engine, and of course more strain if it's moving coolant through the system vs. having all the coolant leak out as you've said.

 

I wouldn't have thought it would be the compressor itself since it blows cold and seems to work fine when the system is charged (other than the engine bogging), but like I said, I don't know a lot about the A/C system.

If someone has had their compressor go bad without it locking up completely, I'd love to hear their insight.

 

Did you get it charged at a shop or did you do it your self? Could be way over charged causing the compressor to stay on.

 

I charged it myself, but it wasn't staying on. I could watch the compressor clutch disengage when I turned off the air, and it wouldn't blow cold air when it was turned off. Also, I have a gauge, so I watched it as I filled it to make sure it wasn't overcharged.

I am curious if it may not have gotten enough oil though. The cans of refrigerant I bought was supposed to have it all mixed in, but if the system was completely empty, I wonder if it was enough? Maybe the can mixtures are biased to top off a system instead of completely refilling it? I don't know, just a thought. I'm just hoping to avoid paying a $1500 shop bill for a 13 year old vehicle.

 

You should not have to add oil. Unless you change the compressor or other components in the ac system. Did you vacuum out the system before recharging it?

 

No, I just started adding refrigerant until it started working again and the pressure was in the green. The A/C wasn't working when I bought it, so I was hoping just topping it off would get it going again. It ended up needing a few cans to fill back up, so it seems to have been empty of R134a anyway. To get the right balance of oil it might be a good idea to have it vacuumed next time. I hadn't even thought about that; I wonder if the system had too much oil in it, causing a pressure increase inside the compressor?

 

The point of vacuuming the system out is to get all the moister out of the system. When you say you used a gauge are you talking about real AC gauges or the one on those cans you get at the store. Cause those are universal they really don't tell you much. Also when you vacuum it out you can fill it up by how much it takes and don't have to worry about over filling it.

Here is a good video on refilling it your self.