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Old 06-11-2019, 01:48 PM
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Default AC system replacement help

Hey all,

I'm replacing my compressor, drier, orifice tube and lines on my 02 TA.

Im going to have a shop flush, vacuum, and then fill the refrigerant.

Question is, should I mount the drier and leave the lines disconnected until I take it to the shop? I presume I don’t want to hook everything up and then have it sit for a few days before the shop gets around to flushing and applying vacuum? Don’t want the desiccant in the drier to go bad.

Thanks!
Old 06-11-2019, 09:38 PM
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You could put them together hand tight, or get rubber plugs at the hardware store, or even just use duct tape.
Old 06-11-2019, 10:01 PM
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Why not do it yourself?

My system was leaking and since I had to open it anyways to replace the motor mount through bolts I went back through the system and replaced all the seals and the orifice tube. Figured its probably time after 18 years but I put it all back together and didn't even pull a vacuum on the system. Just added the 9oz of PAG46 I think it was and 24oz of freon. It blows a cool 47°-50° out of the vents once it gets going and I'm still running the original A/C components that came with the car.
Old 06-11-2019, 10:47 PM
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I’d prefer to have the shop flush and pull a vacuum to get all the moisture out before filling with refrigerant. Just want to make sure it’s done right

i was foncerned about hooking up the drier without pulling a vacuum on the system and having moisture trapped in there. I read that the desiccant in the drier can go bad if exposed for as little as 30 min.
Old 06-18-2019, 12:34 AM
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I'd take an air blower n blow out evap core and condenser. Unless ur compressor took a huge crap n you had debris stuck in orrifce tube... I wouldn't worry about flushing. Hook everything up and let them put it i to a vacuum and charge the system
Old 06-18-2019, 07:08 PM
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So how's the duct tape working out?

If you REALLY want to bite off, then, well, yerbasic 200 mph tape just ISN'T gonna cut it. I ran across this the other day in a cargo hold situation: 600 mph tape. Now tell me that's not good enough for this application.

https://catalog.berryglobal.com/prod...dhesiv228225fr
Old 07-03-2019, 05:04 PM
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Originally Posted by FU_I_AM_UltraZ
I'd take an air blower n blow out evap core and condenser. Unless ur compressor took a huge crap n you had debris stuck in orrifce tube... I wouldn't worry about flushing. Hook everything up and let them put it i to a vacuum and charge the system
I got the compressor, accumulator, condenser, and belt replaced along with all new gaskets. Added 9oz of PAG 150 oil, and now I’m pulling a vacuum on the system.

Anyone know what vacuum level I should be hitting? I’ve got the high and low pressure hoses connected to the ports, both open, and the vacuum gauge ports both open, with the vacuum connected to the yellow port on the gauge, and I’m only getting about 15in Hg vacuum with the pump running?

if I close the high pressure port, the low pressure side will climb to 25in Hg.

Everything ive read said I should be seeing 30in Hg????

thanks!
Old 07-03-2019, 05:18 PM
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Found the problem

vacuum gauge set had had a small leak on the hose. Swapped out with another hose and now I’m getting 30in Hg with both connected
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Old 07-03-2019, 11:23 PM
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Okay, really need some help here.

System held 30in vacuum for an hour, then I vacuumed the system for an hour and then double checked to make sure it held vacuum for another 30 min.

To check holding vacuum, I connected the gauge set to high and low pressure ports, then opened the ports, turned on the vacuum, then opened the gauge valves.

After vacuuming for for an hour, closed the gauge valve with the high and low ports still open.

After it held for 30 min, I closed the ports and disconnected the gauge system.

To add the R134a, I connected the can to the low pressure port, with the valve closed, I turned on the car and set the AC to max, and turned the fan to high.

Went back to the ebgine bag bag and opened the refrigerant can. Took about 5 minutes and the van emptied. During this time, the drier got cold to the touch and it sounded like the compressor was kicking on. Disconnected the empty can and repeated for the second can. I weighed the cans to confirm that I had added 24oz.

Unfortunately the AC was not cold

reconnected the gauge set and pressure on the high and low port was 0?

reconnected the vacuum and pulled another vacuum. Held pressure for another 30 min????

i don’t understand what could be happening?
Old 07-04-2019, 11:27 AM
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You should have had the shop flush and pull a vacuum to get all the moisture out before filling with refrigerant. That way you could make sure it’s done right
Old 07-04-2019, 07:44 PM
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Originally Posted by 01CamaroSSTx
You should have had the shop flush and pull a vacuum to get all the moisture out before filling with refrigerant. That way you could make sure it’s done right
I had the shop evacuate the refrigerant and then I pulled a vacuum for a long time. No problems holding vacuum at all. In fact it’s been holding vacuum all day today as well.

Im wondering if there isn’t a leak at one of the line connections when the system goes under pressure that doesn’t show up when it’s under vacuum.

Ill probably take it Ken it to the shop for a leak test and fill of refrigerant tomorrow.
Old 07-04-2019, 08:57 PM
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When you pulled a vacuum and shut the pump down the needle should held steady and not move. Don't close the high and low side valves leave them opened when you shut the pump down and If you notice the needle is falling after shut down then you have a leak.
Old 07-04-2019, 09:09 PM
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Make sure the wire to the compressor is connected correctly and the wire to the pressure switch on the line for the orifice tube is connected. It just may be that the pressure switch on that line may be bad and need to be replaced also.
Old 07-04-2019, 10:33 PM
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Originally Posted by 01CamaroSSTx
When you pulled a vacuum and shut the pump down the needle should held steady and not move. Don't close the high and low side valves leave them opened when you shut the pump down and If you notice the needle is falling after shut down then you have a leak.
When I turned the pump off I kept the valves that were directly connected to the high and low side ports on the car open and shut the valves on the gauge body. The needles have held steady for 24hrs.

the electrical connector on the compressor is connected correctly, and the compressor kicked on temporarily when I added refrigerant. The system took all the refrigerant, but must have spit it out somewhere, because the system is completely empty now.
Old 07-05-2019, 07:52 AM
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I am a bit inexperienced w/ automotive A/C service. That being said, I will make/ask a few comments/questions.
  • You wrote “To add the R134a, I connected the can to the low pressure port”. Do you mean you charged the low side through the manifold with the high side manifold (gauge) valve closed?
  • Were your high and low side pressures within spec, considering ambient temperature and relative humidity, after charging?
  • Is your high side service port schrader or ball-type? I believe OEM on my 98 TA is schrader. Those ball-type valves often do not seat completely after being pushed open. Are your service ports leaking after disconnecting the manifold set couplers?
  • Did you add A/C UV dye?
Old 07-05-2019, 08:41 AM
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Originally Posted by bsf
I am a bit inexperienced w/ automotive A/C service. That being said, I will make/ask a few comments/questions.
  • You wrote “To add the R134a, I connected the can to the low pressure port”. Do you mean you charged the low side through the manifold with the high side manifold (gauge) valve closed?
  • I wasn’t able to use the gauge set when refilling because of the type of can hose I had, so I disconnected the gauge set and connected the refrigerant can directly to the low side port on the vehicle.
Originally Posted by bsf
  • Were your high and low side pressures within spec, considering ambient temperature and relative humidity, after charging?
  • my can hose did not have a gauge so I couldn’t read any pressures while filling
Originally Posted by bsf
  • Is your high side service port schrader or ball-type? I believe OEM on my 98 TA is schrader. Those ball-type valves often do not seat completely after being pushed open. Are your service ports leaking after disconnecting the manifold set couplers?
  • Did you add A/C UV dye?
i believe the ports are Schrader style as they look like bicycle tire connections . I have UV dye in the system and there are some small signs under UV light at a couple of hose connection points, but there was also loose refrigerant at those points during the disassembly and reassembly. I would expect there to be a pretty decent spray of refrigerant of the whole system just completely emptied out instantly as it was added.
Old 07-05-2019, 09:27 AM
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Have you checked inside the car for evaporator leaks? So far this whole discussion has been under the hood.
Old 07-05-2019, 09:58 AM
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Originally Posted by G Atsma
Have you checked inside the car for evaporator leaks? So far this whole discussion has been under the hood.
The system was working perfectly prior to the compressor replacement. The only issue was that he compressor was starting to make noise and with 130k miles I decided to go ahead and replace the major system components.
Old 07-05-2019, 01:00 PM
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Just heard back from firestone, gasket on the low pressure port going to the condenser was leaking. That was one of the brand new gaskets I installed. They are replacing now and should be back on the road shortly. Hopefully no other leaks

I even bought the official GM gasket set!

Still not sure how the system could hold a vacuum during all of that, and if that thing was leaking, sort of concerned that I’ve got a ton of moisture in the system and may have killed my new accumulator.

Any idea how to tell if the accumulator is bad?
Old 07-05-2019, 02:12 PM
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Default What I do to charge my AC system and to detect leaks

Originally Posted by ws6-speed
Just heard back from firestone, gasket on the low pressure port going to the condenser was leaking. That was one of the brand new gaskets I installed. They are replacing now and should be back on the road shortly. Hopefully no other leaks

I even bought the official GM gasket set!

Still not sure how the system could hold a vacuum during all of that, and if that thing was leaking, sort of concerned that I’ve got a ton of moisture in the system and may have killed my new accumulator.

Any idea how to tell if the accumulator is bad?
Since yours is "brand new" you should be just fine if you or the shop you take it to, pulls a vacuum on the whole system and gets it to between 28 and or 30 Inches and you ONLY pull vacuum from the low side, high side should always be kept closed when pulling a vacuum on the system. If you let your vacuum pump run for a while, it will remove the moisture from the accumulator and of course evacuate the whole system removing moisture from the air in the system as well. Now if your system has been open for a year or over the winter or what not, Yeah you are screwed. But if you are talking a few minutes to a few hours, you are fine. Do NOT have to replace the accumulator again. If you evacuate the system for an hour or a few hours to have beyond a shadow of a doubt that as much moisture is removed from everything you will be just fine. As long as you pull a vacuum on the system prior to recharging it, by doing that you have a very VERY slim chance you will have issues. The warning of "a few minutes to a few hours" usually is for the people that do not understand how A/C works and will just grab those recharge cans and dump them into a system with no Vacuum, or if they did some sort of repair and their system leaked out end of last summer and the thought of Oh screw it ill deal with it next spring or summer, Fix an O ring or something and then just charge it without ever pulling a vacuum, and not attempting to do it correctly and remove as much moisture out of the system as possible, Those are the folks that will have issues and probably destroy their entire A/C system and need every hose, fitting, valve, Condenser, Compressor, Accumulator/receiver drier, High and Low pressure switches, Orifice tubes etc.

Also when you pull a vacuum on the system the schrader valves will usually allow air back into the system because they are more or less set to hold pressure in the system and the little teeny tiny spring can't hold the vacuum in the system once you remove the hoses from your manifold/gauge set. So thats why you have to leave your hoses on and close the manifold valve on the low side (High side should always be kept closed when pulling a vacuum and charging the system) Only open the high side to get a pressure reading after you are done charging it with fresh 134A.

Someone else said they could not hook up their refrigerant can to the manifold/gauge set? Be Careful as to why that is.... That's what the manifold/gauge set is for and you should not need any additional connectors to connect the refrigerant can to the yellow hose....Ensure you have the correct refrigerant for your application, R12-R22 or R134a??? All modern cars use R134a so double check you are not trying to utilize the incorrect refrigerant in your application
You use the Yellow center hose to connect the refrigerant can (R134a) to and open the low side (blue hose connected to the accumulator or low pressure line by the accumulator and Red or high pressure to the line by the condenser)
This is how I do my A/C Charges and ensure the system is sealed before adding R134a.............
Car off....Check Schrader valves and ensure they are clean and springs are working by removing them and inspecting them, replace as necessary. Use a deep 5/32" quarter inch drive socket, use a whizzer wheel or metal saw to cut a groove at the end of the socket about 1/4 inch deep and 1/16th wide. Remove/inspect/reinstall/Replace if needed both Schrader valves.
Jumper 12V to AC Compressor clutch to ensure electromagnetic clutch engages the pulley on the compressor. Connect Blue hose of your manifold and gauges to low side, Red to high side.......Close high and low side valves on the gauge manifold, open valves at Schrader valves/end of red and blue hoses, (The quick disconnects usually have a valve you can close or open, ensure they are opened to get vacuum or pressure readings)
1. Pull vacuum by connecting vacuum pump to yellow center hose on Manifold set, open valve on low side (Blue)
2. Pull to 28-30 Inches of vacuum and run for a few hours if a lot of moisture in system or if system has been open for a while
3. Close low valve (High side should always be closed during this procedure) Once you have 28 to 30 inches of vacuum, close valve and wait to see if the pressure drops. Few hours should be sufficient, overnight for the perfectionist.....Remove vacuum pump from yellow hose.
4. Once you feel you have waited long enough and vacuum still holding, Manifold/gauges still connected and valves both closed still.......Connect refrigerant can to yellow center hose end or auxiliary refrigerant connector at the T where yellow hose connects to manifold gauge set...........
5. Crack open the blue or low side valve on the manifold and the vacuum you pulled from the vacuum pump initially connected to the yellow line, now takes the refrigerant up the yellow hose, You will see it in the sight glass in center of manifold and will flow down blue line into low side of the system. Empty the can into the system since your system is completely empty and has 28-30 inches of Vacuum it will suck it right in. (Gently shake can and hold upside down until empty) Close low side manifold valve, Remove can and with safety glasses and gloves, allow the little bit in the lines to escape, and attach 2nd can, open blue manifold valve again and dump what MFG recommends to be added to fill it completely. (1998 to 2002 is 24 ounces or 2 regular size cans)
6. Add oil per MFG same way as refrigerant (***NOTE*** Some refrigerant cans have oil in them to do not add too much oil!!!)
7. With manifold valves closed, Start the car and turn A/C system on and using a vent thermometer, make sure its blowing cold and verify the clutch on the compressor is cycling and no squeaking or noise from the compressor other than the clicking of the electromagnetic clutch. Open the high and low side manifold valves and get a pressure reading.
8. The Pressures should read based on ambient temps about 5 to 13 + or - PSI above the ambient temps. (Example: 90 degrees outside, pressure should read about 95 to 103 + or - a degree or two. Just a ball park way to know if you are too low or too high but as ambient temps change the pressures will change with them.
9. Disconnect all Manifold hoses and lines, check system for leaks with a leak detector or oil dye with a UV Flashlight
a good efficient system should be discharging air in and around the 40 to 45 degree temp into the car/truck's cabin at the coldest setting possible.
***NOTE*** Digital A/C and Heat Systems that have a programmable temp and readout is what the heat/A/C system will keep the cars interior temp at. It is NOT the temp of the A/C Air coming out of the vents. So if you have your digital thermostat set at 70 degrees, the A/C system will run a high fan speed and blow cold air out around 40 to 45 degrees until the temp inside the car reaches the settings on the thermostat and then fan speed will slow down by itself, Usually Corvettes, Cadillac's and such have Heat/AC systems that do this, F Bodies have the old dial type Thermostats which will just blow cold air out until you manually turn it off or down***NOTE***

Good luck and ALWAYS use gloves and Eye Protection. Refrigerant can freeze your eye instantly and you are blind for life. So wear safety glasses!!!



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