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That doesn't look too bad IMHO and given you're working with HF tools, there's probably and small but significant margin of error here. You can try and squeeze a little more Freon in there but I'd check the cooling fan blades for distortion and the condenser fins for blockage as the system needs air moving through it to work well.
The only way I know to reliably check if the system is leaking (without dyes or a detector) is to get an evacuation pump, pull the system down to 25 or 30 pounds of vacuum, close the gauges, turn off the pump and go grab some lunch. If you still have as much vacuum as you did before you went to lunch, you're golden. If not, you've got to find the leak and I'd start at the compressor seal followed closely by the hose assembly but if those were leaking already, the pressures would probably be lower than that.
You also have to consider that compressors do start to wear and as they do, they don't compress as hard as they used to...she's getting old.
I would top it off and monitor for a few weeks. How much were the gauges at HF?
The gauges were $50. I bought a vacuum pump too, anticipating that it was really low. The pump was $100. I may end up rebuilding the system soon enough. Right now my priority is getting the rear suspension up to snuff. I've got everything but toe rods and the inner LCA bushings (which aren't yet available).
$275 for a pump, condenser and accumulator isn't too bad. I'll just need to flush the rest out well and can use my newly acquired equipment to earn its keep. $150 is nearly recovered in the first use!
That doesn't look too bad IMHO and given you're working with HF tools, there's probably and small but significant margin of error here. You can try and squeeze a little more Freon in there but I'd check the cooling fan blades for distortion and the condenser fins for blockage as the system needs air moving through it to work well.
The only way I know to reliably check if the system is leaking (without dyes or a detector) is to get an evacuation pump, pull the system down to 25 or 30 pounds of vacuum, close the gauges, turn off the pump and go grab some lunch. If you still have as much vacuum as you did before you went to lunch, you're golden. If not, you've got to find the leak and I'd start at the compressor seal followed closely by the hose assembly but if those were leaking already, the pressures would probably be lower than that.
You also have to consider that compressors do start to wear and as they do, they don't compress as hard as they used to...she's getting old.
The fans are OK. I replaced the radiator over the winter and had them out then. All seemed to be well. They were pulling nicely as I tested the pressure today. The engine temps haven't topped 185 in Atlanta summer traffic either.
I have noticed that the compressor is a bit noisier these days. That could be the main problem.
The baffle beneath the bumper cover was ripped out a few months ago and I haven't replaced it. I wonder if that is negatively affecting the airflow across the condenser. I would imagine so.
The baffle beneath the bumper cover was ripped out a few months ago and I haven't replaced it. I wonder if that is negatively affecting the airflow across the condenser. I would imagine so.
If you lost the filler panel on a 3rd gen Trans Am, it would cause cooling issues but on this car, I don't know....it has a lot of open frontal area. Mine was missing when I bought the car and i didn't notice anything amiss while it was off but I'm highway driving so I wouldn't have really noticed issues in traffic. I put one on it anyway.
Is the receiver/drier/xxx easily accessible in these vehicles? I always replace that any time I open a system. If I suspect a leak I will usually replace that then pull a vacuum anyway. I think that's supposed to be SOP anyway when opened but some don't. I'm used to replacing the whole assembly but RockAuto seems to list a desiccant pack/bag and high side filter. I've worked on mostly 2005 and earlier A/C; is this the way new things are or one of the Cadillac oddities?
Is the receiver/drier/xxx easily accessible in these vehicles? I always replace that any time I open a system. If I suspect a leak I will usually replace that then pull a vacuum anyway. I think that's supposed to be SOP anyway when opened but some don't. I'm used to replacing the whole assembly but RockAuto seems to list a desiccant pack/bag and high side filter. I've worked on mostly 2005 and earlier A/C; is this the way new things are or one of the Cadillac oddities?
AC is AC from what I can tell and while the systems have gotten more compact, they still function like the older stuff. The dryer is in the condenser like you think but I haven't been into the system but my day is coming. I don't think its going to be too hard to get to.
Evacuating the system and replacing the dryer is standard procedure if you're going to do it right.
Besides looking for leaks and creating a negative pressure to help charge the system, you pull a vacuum on it to get all the moisture out of it. As I was told, Freon and water create an acidic compound that slowly eats away at the seals.
GM also told us that simply leaving a system open in a humid climate for any period of time (half hour or more?) would be enough time to compromise the dryer so install it last and seal the system up as soon as you can. Of course that was 25 years ago so dryer quality/capacity may have changed a little sense then.
The dryer/accumulator I believe is part of the condenser unit. At least it is sold that way. It is pictured as a tube that runs along the side of the evaporator and is sold as one piece.
The dryer/accumulator I believe is part of the condenser unit. At least it is sold that way. It is pictured as a tube that runs along the side of the evaporator and is sold as one piece.
Not saying that Rockauto is the authority but this is what I was seeing there. Element that goes in said tube. And they don't seem to offer the tube.
Check the condenser part images on rock auto. You'll see what I'm talking about. The tube is attached to the side of the condenser. It's more common to also replace condensers now because their passages are so narrow that flushing really doesn't do anything. Fortunately, they're only about $75.
Yessir, you are right; pretty obvious from the pics. I'm used to paying $50+ for the receiver/drier itself in most cars so this is a no-brainer. Since all that will get replaced and I already janked up at least one of the lines in the engine bay(forgot that @!#$$#% last little bolt on the front/bottom of engine when yanking it), guess I may just replace everything I can get my hands easily on so that means compressor too. 100K seems like a good time.
Do you know if that condenser/receiver/drier assembly has the desiccant pack already in there or would I need to buy that as well?
If the compressor is noisy, you plan on keeping the car and you have the funds slated to do the job, I'd think seriously about replacing the compressor before it let go. Flushing the system after a compressor failure isn't easy and will wind up costing you more in the long run.
Yep, caught that advise. Rather than topping it off, I think I'll hold off til I can do it right. The right way to recharge would be to evac the system, put it under vacuum and add the prescribed amount back in. I don't have a recovery machine and would rather not pay to recharge if I plan to open the system back up soon anyway.
I need to check mine to see what the low side gauge shows and see if it needs a little added. Would it hurt if I hook the Refill can and gauge to the low side while it's running? I know On most cars you can do that but I was wondering if you can do that To these cars with no problems without sucking in air or whatever? I'm scared to take off the low side cap Before I got some answers
06-12-2016, 06:22 PM
Aging System - AC pressure check 
