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Post by jmurdr1 on Jun 27, 2015 17:14:58 GMT -6
How hard is it to fix your own AC? I think I possibly have a leak. Really miss having AC in my car with it hitting around 100 here lately I already know the compressor is OK and I need to replace the driver side blend door motor but I filled it up with r134 and now its not getting cold anymore like when I refilled it a couple months back... Anyone know what the typical AC probs are with a 99?
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Post by Toronado3800 on Jun 28, 2015 20:58:28 GMT -6
Are you able to tell if it still has your 134a or if it all leaked out?
Also I suppose, is there any sign the lines are getting cold with it on? Hate to have you working on the A/C when it is just internal climate control stuff.
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tigger
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Post by tigger on Jun 28, 2015 22:34:34 GMT -6
^ Yeah, you really need a pressure reading to know where to start. A lot of auto parts stores rent/loan manifold gauges...
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Post by turbokinetic on Jun 29, 2015 7:38:38 GMT -6
I am no expert on the layout of these cars, as our family has a 95 and it's the only Aurora I have worked on. But I have made numerous A/C repairs to other GM cars.
If I encounter a car where the A/C compressor won't engage, I usually follow a basic procedure before "digging in deep."
First, start with the basics. Have you made a visual inspection of all the lines? Have you tried to turn the compressor by hand? (engine off!) Have you checked for dislodged electrical connectors?
The next step is to install a gauge on the low-pressure service port. You can use a cheap one such as that which comes with a can of refrigerant. High pressure gauge not needed, only need to check the low side to troubleshoot at this point.
Connect the gauge with the engine off and the car cool, such as in the morning. On a hot day, the pressure should be about 100 PSI with the temperature around 90°F. It may be much higher if the car is hot because engine running. If it's above 70 or 80 PSI, do not add refrigerant at this time. This should be enough to make the compressor engage. If the pressure is 0, you have to troubleshoot the leak at this point.
On our Aurora, which we bought used, someone had previously installed a replacement compressor. The compressor sounded a little bit loud but not alarmingly so. The A/C worked when we got the car, but it eventually developed a leak.
There are only two rubber hoses on the refrigerant system, both of which connect between the compressor and the body. Everything else is alumimium tubing. The leak turned out to be the compressor suction hose, where it had rubbed against the car body. There is an "angle bracket" (for lack of a better word) connecting the frame rail (under body outboard of the subframe) to the bottom of the radiator support. The compressor hose goes by this and was touching the edge of the bracket. After pulling off the plastic covers from the bottom of the car, I could see the hose damage and see compressor oil around the area.
The hoses bolt to the back of the compressor with one bolt; and then connect to the bottom of the dryer canister and to the condenser coil. Any "better" parts store can remove and replace the rubber part of the hoses, preserving the aluminium sections. I took the hoses to the store and had them repaired with new rubber sections.
Because the compressor was loud, I chose to replace it at this time. Having been burned by the knock-off Chinese "NEW" compressors, I bought a General Motors Delphi unit. To go with it, I also installed a new dryer (keeps the refrigerant gas dry and clean) and orifice tube.
When I took the orifice tube out, it had metal chips on its screen. Turns out the original people put the new compressor on the car and did not remove the failure debris from the original one. Due to the design of the condenser, it is not feasible to clean the interior of it. A new condenser was reasonably priced, so I simply replaced it. To finish the system cleanup, I flushed the old oil out of the evaporator core with brake parts cleaner, and then started with a fresh system.
That was the first A/C problem with the Aurora. About 2 years later, it leaked down again. This time, I found the leak was a temperature sensor in the refrigerant line. It is on the high pressure liquid line, mounted near the right front corner of the engine compartment. This had a crack in it and the refrigerant was coming out around the electrical connector. It was not expensive, however the entire refrigerant charge had to be evacuated because the sensor goes into the line without any sort of valve core.
I hope this helps, and I will try to add info if time permits. Sincerely, David
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Post by turbokinetic on Jun 29, 2015 15:06:34 GMT -6
I was looking through the 1995 factory manual and there is a very good A/C troubleshooting chart. You probably need to look up a 1999 service manual because there was a major change to the electrics and software. (wentfFrom ALDL to OBDII)
On the 1995 model car, there are no trouble codes which permanently disable the compressor by virtue of being stored in memory. If the system goes out of tolerance and sets a DTC, the system resets and the compressor will work again when the engine has been stopped and started.
Sincerely, David
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Post by jmurdr1 on Jun 30, 2015 14:59:12 GMT -6
If I change out one of the rubber hoses or a compressor suction hose does the system always have to be vacuum pumped out?
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tigger
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Post by tigger on Jun 30, 2015 18:57:40 GMT -6
Pulling a vacuum is highly recommended any time you open the system. It'll let you know if you fixed the leak (leaking system won't hold a vacuum), and boil off any moisture introduced from opening the system.
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Post by turbokinetic on Jun 30, 2015 20:31:53 GMT -6
If I change out one of the rubber hoses or a compressor suction hose does the system always have to be vacuum pumped out? Yes. It is absolutely critical. The system depends on the refrigerant gas in the system to be pure refrigerant gas. This gas is special, because it will change from a gas to a liquid at a very predictable and safe pressure level. If the refrigerant gas is blended with air, there will be problems. Air is "non condensable gas" and will severely harm the performance of the air conditioner. Furthermore, the air contains oxygen and water vapor. The water vapor will react with the chemicals in the system and cause corrosion of the compressor and deterioration of the compressor oil. The oxygen is an unsafe condition because R134A and compressor oil are combustible materials. You don't want to compress them together with air. This will lead to oxidation of the oil and in a severe case, could pose an explosion hazard. Here is a video where I re-do the A/C on a 1980 Olds Cutlass. It is the same basic design and this may give you some ideas on what to expect for hose removal. The Aurora hoses are positioned differently, but the idea of changing the O-rings and looking for leaks and evacuating the system is the same. I thought I had posted this once already but I guess I got interrupted before it was posted. I have a lot of air conditioner videos on my channel, by the way.
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Post by jmurdr1 on Jul 3, 2015 11:50:36 GMT -6
Thaanks. That was a good video....I think thats something I could possibly do
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Post by turbokinetic on Jul 4, 2015 9:24:00 GMT -6
Thaanks. That was a good video....I think thats something I could possibly do You're welcome! Glad you found it useful. I have had a lot of success with auto air repairs, but I learned the hard way early on. I like to share this experience so maybe someone else doesn't have to learn the hard way!
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Post by jmurdr1 on Jul 5, 2015 13:54:02 GMT -6
Right on bro... Keep up the good work I learned a thing or two
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Post by theghost on Jul 8, 2015 10:26:08 GMT -6
I have 99.. I recently had my blower motor replaced. My a/c worked fine for about two weeks before any problems. I opened my door yesterday to the smell of mildew and wet carpet on my driver and passenger side. Upon further inspection I let the a/c run for awhile. Condensation built up and could actually see water dripping from under the dash. Could this be bad installation?, or a drainage problem?.
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bobsblue95
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Post by bobsblue95 on Jul 8, 2015 10:46:26 GMT -6
Sounds like the condensation drain is clogged. Fairly hard to get to on the firewall, not far from the HVAC plumbing connections.
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Post by theghost on Jul 8, 2015 10:49:39 GMT -6
Thanks for the heads up, Im headed to get it checked out now.
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