01 Century A/C Problem

[Maymybonneliveforevr]

The a/c has always been cold up until this year for the 01 Buick Century 3.1. There is absolutly no cold air coming from the vents and the a/c compressor doesn't engage or cycle. I'm not sure where the relay is but I was thinking of putting the Harbor Frieght a/c gauges on and seeing if there was any pressure and how much in the lines.

Does anyone know what the high and low side pressure range should be on the above car?


Any suggestions would be appreciated.

Thanks

[RJolly87]

The ranges vary based on humidity and temperature, but the compressor not engaging or cycling is the dead give away. If you throw the gauges on it, there should be pressure, usually it takes 30-40psi minimum to kick over the compressor. Usually a fully charged system will have in excess of 100-125psi at rest. If you check it, and there is no pressure, you need to find your leak, and fix it. If there is enough pressure, you should look at other things, relays, wiring, etc.

[Maymybonneliveforevr]

Thanks for the reply RJolly87, you've given me a starting point.

[Maymybonneliveforevr]

Just an update,

The a/c was recharged and worked great to about 40 degrees F but after 4 days it stopped working and the clutch no longer engages. This give me the impression that there is a leak in the system which I don't know where to start to repair. A/C repairs in Canada are expensive so it looks as though we'll no longer have A/C in the 01 Century.


Thanks for everyones help.

[RJolly87]

The best bet is to put UV Dye in the system and have it charged, and then look for the leak a day or two later with a black light.

[bs009]

My bet would be on the condensor. It's a common place where leaks develop in Regals. Next place I would check is the compressor.

x2 on the UV dye.

[gmman]

harbor freight also has a freon leak detector for about $70. might be worth a try to sniff around condenser, compressor, lines and ports. if you do not have screw on caps for your high and low pressure ports, the schrader valves have been known to bleed down system (the caps may be present but not tightly screwed down). the sniffer will also tell you if these valves are leaking. if the sniffer is unable to detect a leak under the hood, sniff the ac vents in the dash. could also be the evaporator.

[Maymybonneliveforevr]

Thanks for all the replies everyone.

The best bet is to put UV Dye in the system and have it charged, and then look for the leak a day or two later with a black light.

I noticed the UV Dye is not expensive, but will any black light work?

My bet would be on the condensor. It's a common place where leaks develop in Regals. Next place I would check is the compressor.

Thanks for the advice, I'm going to add what it will cost to do a test.

harbor freight also has a freon leak detector for about $70. might be worth a try to sniff around condenser, compressor, lines and ports. if you do not have screw on caps for your high and low pressure ports, the schrader valves have been known to bleed down system (the caps may be present but not tightly screwed down). the sniffer will also tell you if these valves are leaking. if the sniffer is unable to detect a leak under the hood, sniff the ac vents in the dash. could also be the evaporator.

The 01 Century does have screw on caps.

Ok the running total will be,

UV Dye/Black light $21.00
Snifter $70.00
R-134a $35.00

Whether I use the UV Dye or Snifter, I'm looking at around $60.00- $100.00 just to find the leak, then the cost of repair and another freon charge. If I knew I could find the leak then I would do it, but I'm not sure I'll be able to troubleshoot.

[gmman]

so you spend this money and you can't find the leak with either method or you find the leak but it turns out to be the compressor. compressor can be $200 up. guess you weigh cost maybe up to $300 or more against no air. if you find the leak and decide to replace compressor, condenser or whatever, the club can help with tips about replacement. it is a formidable undertaking if you have no experience in this area. so, you can look at it as taking a course in auto AC repair. some members decide to take the challenge *dang* the torpedos rather than pay dealer costs or go without air. success is not guaranteed but from my own experience, it is within the capability of most members.

PS if you want to go whole hog, buy the vacuum pump from harbor freight $130 on sale and a complete R 134A recharge plus oil and leak inhibitor kit with gage and charging hose for about$40. that way when you fix the leak you can evacuate the system and at the same time verify the leak is repaired before attempting to recharge. if there is a leak the vacuum pump will not be able to reach or maintain about 28 psi negative pressure (vacuum). PS PS come to think of it, you have nothing to lose from trying the recharge kit from Walmart which contains a leak sealer BEFORE YOU TRY ANY OF THE ABOVE MEASURES.

[Bugsi]

I used to service A/C systems, but it's been like 25+ years, and everything was R12 and R22 back then. Still, I can give you some advice based on the most popular mistakes I've seen people make:
I've totally forgotten the correct pressures, but if you buy the gauge, it will have some indication of correct pressure, like a green zone or something, and "correct" is different on the high side than on the low side. (Always charge from the low side!) Note that the pressure is different with the system running, than when it is off (for example, when your engine is not running). When the compressor is running there should be a good differential between the high pressure side and low pressure side. When you shut off the car, these equalize over a minute or so. (After totally re-doing a friend's system so it was working perfectly, he went out and bought a gauge, measured the low-side pressure with the vehicle off, freaked out at how high it was, and then bled off R12 until the gauge measured the "correct" low-pressure, then complained to me how I'd over-charged his system and how he "fixed" it by letting out the freon, and . . .then it didn't work!) So remember: Measure pressure with it RUNNING.

Since your compressor isn't running a few days after you charged it, you have a leak. Common leak locations are: Compressor, condenser, evaporator, and any of the seals where hoses connect to components. Troubleshooting A/C isn't rocket science. Find your leak and replace the defective/leaking parts. You or a shop can use the dye to find your leak.

Once you find your leak, you need to open the system to fix it. With R12 and R22 it was a big deal to use a recovery system to collect any refrigerant still in the system before opening it up (as opposed to venting it to the atmosphere.) I have no idea if they do that with R134A (someone chime in if you know). Presuming they do that, you generally need a shop to do it. (You could have a shop do *just* this, for example, and do the rest of the work yourself.) -Then replace whatever is bad. On an older vehicle, if I'm opening up a system to replace the compressor or condenser, for example, I use that opportunity to replace all the seals at any connections, and the orifice tube or expansion valve.

When everything is replaced that needs replacing and buttoned up really good, you can use your Harbor Freight vacuum pump and your Harbor Freight manifold gauges to pump down the system really good and let it sit to verify that it holds a vacuum. If everything is "go" then you can begin charging with R134A. Pay attention to what you're doing so you don't put atmospheric air into the system.