So I am replacing every part of my AC system except for the compressor. Do I need to do anything to the system before I charge it? The old collector dumped a fair amount of oil, but the new one doesn’t have any in it.
Do I need to do anything to the A/C system before I charge it?
- Thread starter Vidar
- Start date
It needs to be evacuated to get all the water out, I don't think you can just charge an empty system without at least doing that.
You need to replace same amount of oil that was taken out of the accumulator. If not known drain compressor and replace with amount recommended by manufacturer
If you have the time, run a flush. You can get flush kits on Amazon to flush out the entire system. Especially do this if you're not replacing the evaporator.
Another advantage of the flush is that you can precisely measure the amount of PAG oil in the system. Too little and the compressor will fail. Too much and the compressor will hydrolock and fail catastrophically.
Replace the accumulator unless it is new and the system will only be discharged for a short period. If it is not new or there has been a leak, replace it. There is a desiccant in there to remove water vapor from the system.
Prior to recharging the system, you will need to use a vacuum pump to pull a vacuum on the entire system. Amazon and Harbor Freight have some decent kits.
Another advantage of the flush is that you can precisely measure the amount of PAG oil in the system. Too little and the compressor will fail. Too much and the compressor will hydrolock and fail catastrophically.
Replace the accumulator unless it is new and the system will only be discharged for a short period. If it is not new or there has been a leak, replace it. There is a desiccant in there to remove water vapor from the system.
Prior to recharging the system, you will need to use a vacuum pump to pull a vacuum on the entire system. Amazon and Harbor Freight have some decent kits.
OP
I was saying collector, but I meant the drier/accumulator. Everything is new but the compressor, I even bought new lines. Is there a way to drain the oil from the compressor?
Remove the compressor and with the ports pointing downward rotate the compressor in the normal direction of rotation into a graduated container.
There are a few good videos on YouTube. Easiest way is to remove the compressor and pour it out, though this may not be practical.
A chemical flush will also dissolve most oil.
Personally, I would skip replacing the evaporator unless I knew it had an issue. It's a lot of work to remove the dash. (If you do, consider doing the heater core at the same time.)
A chemical flush will also dissolve most oil.
Personally, I would skip replacing the evaporator unless I knew it had an issue. It's a lot of work to remove the dash. (If you do, consider doing the heater core at the same time.)
Yup, the only time an evaporator or condenser need replaced is a leak or a catastrophic failure of the compressor.
OP
I’m rebuilding everything due to a broken piston skirt. Heater core was shot so the evap got replaced. Grill got pulled and painted, so I figured I’d replace the condenser while I was there (23 years of rocks did damage to it). I had a leak in the system and was losing charge before the engine went, so I figured I’d just replace all. Unfortunately I already put the compressor back on, so it looks like it will be coming out again.
Thanks for all the help.
Thanks for all the help.
Rubicon John
TJ Enthusiast
It needs to be under a vacuum for a while before it’s charged. 30 inHg.
I would prepare the system and take it to someone with an AC machine. They can verify it holds a proper vacuum which means it’s sealed and keep it under a vacuum which rids the system of moisture and contaminants and then charge it to the exact weight.
I would prepare the system and take it to someone with an AC machine. They can verify it holds a proper vacuum which means it’s sealed and keep it under a vacuum which rids the system of moisture and contaminants and then charge it to the exact weight.
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OP
Should I fill the compressor with new oil before taking it in, or will the shop do that?
Rubicon John
TJ Enthusiast
X2 on taking the Jeep to someone that has an Evacuation/Recharge machine. Years ago people would evacuate to approximately 29.95" Hg, but now a days a Micron meter is used to measure the depth of vacuum and provides a more accurate static vacuum reading.
Vacuum should be drawn to <500 microns and held for 25-30 minutes for to determine if there is a leak in the system. Weighing in the refrigerant is the most accurate way to charge an empty system. I know some technicians that actually add a couple ounces more to trim the charge.
Good luck with the repairs.
Vacuum should be drawn to <500 microns and held for 25-30 minutes for to determine if there is a leak in the system. Weighing in the refrigerant is the most accurate way to charge an empty system. I know some technicians that actually add a couple ounces more to trim the charge.
Good luck with the repairs.
Just make sure that the shop knows you did not add oil to the system, Typically TJ's take about 8 ounces of refrigerant oil and it must be portioned out to each component of the system. In a dry system the approximate distribution would be 4 oz to the accumulator 2 oz to the condenser and 2 oz to the compressor. Question, did you use the proper O ring lubricant at each of the tubing and hose joints.
OP
OP
So far I’ve only made the connection from the accumulator to the evaporator. I used a bit of the refrigerant oil. Is there something different/better I should use?
If I add the oil myself, do I need to put it all in the compressor or break it into the individual components as you noted?
There is a lubricant specifically designed for 134A "O" rings readily available that should be used.
The oil must be added to each individual component not all in the compressor.