Removing A/C components during repairs
Thread Starter
Senior Member
Joined: Jan 2017
Posts: 541
Likes: 70
From: Southern MD
Model: Cherokee
Removing A/C components during repairs
Pulling engine/trans for rebuild and overall rehab of 2001 XJ.
For the removal of the A/C components what do you all do ? just disconnect and let the gas out? then tape over the connections so no bugs get in there??
Nick
For the removal of the A/C components what do you all do ? just disconnect and let the gas out? then tape over the connections so no bugs get in there??
Nick
Senior Member
Joined: May 2015
Posts: 818
Likes: 35
Year: 1994
Model: Grand Cherokee
Engine: 5.2L Magnum V8 220hp 285ft-lbs
Safety first! The R134a gas must be properly handled to avoid personal injury. Wear eye and skin protection.
The A/C can be moved to the side, remaining full and intact, during all repairs and service, including yanking the engine.
If the A/C must be disassembled, such as for yanking the heater box, then the appropriate process is to have it evacuated using a recycle machine. The R134a should not be dumped into the atmosphere.
When I purchased replacement A/C parts the ends were capped, not sealed.
Once the components are assembled, a vacuum pump is used to evacuate the air and evacuate the moisture. When first turned on the moisture is visible as a fog exiting the vacuum pump exhaust.
Then everything is shut down to verify the system can maintain a solid vacuum w/o leaks.
Remember that there is oil distributed throughout the system, so if parts are replaced, then measure the oil volume within that part for proper fresh oil replacement volume.
The A/C can be moved to the side, remaining full and intact, during all repairs and service, including yanking the engine.
If the A/C must be disassembled, such as for yanking the heater box, then the appropriate process is to have it evacuated using a recycle machine. The R134a should not be dumped into the atmosphere.
When I purchased replacement A/C parts the ends were capped, not sealed.
Once the components are assembled, a vacuum pump is used to evacuate the air and evacuate the moisture. When first turned on the moisture is visible as a fog exiting the vacuum pump exhaust.
Then everything is shut down to verify the system can maintain a solid vacuum w/o leaks.
Remember that there is oil distributed throughout the system, so if parts are replaced, then measure the oil volume within that part for proper fresh oil replacement volume.
CF Veteran
Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
What he said, and yes, if you have an open connection, take steps to keep the bugs out.
A local shop will probably evacuate the system for a reasonable fee, and then properly refill it after you are done. Can't hurt to call around and price it.
Please understand it is not just a matter of letting the gas out and then refilling it later. If you open the system to the atmosphere you must get all that air (with the moisture that is in it!) out of the system before it is refilled. That requires a vacuum pump.
If that's all news to you, best to let the pros handle it.
A local shop will probably evacuate the system for a reasonable fee, and then properly refill it after you are done. Can't hurt to call around and price it.
Please understand it is not just a matter of letting the gas out and then refilling it later. If you open the system to the atmosphere you must get all that air (with the moisture that is in it!) out of the system before it is refilled. That requires a vacuum pump.
If that's all news to you, best to let the pros handle it.
Last edited by BlueRidgeMark; May 8, 2017 at 06:58 AM.
Thread Starter
Senior Member
Joined: Jan 2017
Posts: 541
Likes: 70
From: Southern MD
Model: Cherokee
Thanks, we are doing a full rebuild of the XJ, so the A/C components all need to come out. it's a non drivable XJ sitting in my garage, not sure how to have it evacuated.
Slack
Slack
CF Veteran
Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Hmmm. Well, the officially correct answer is to have it towed to a shop that can do it.
The incorrect, illegal answer is to just open a connection. But I'm not suggesting you do that....
Maybe you can rent an extractor pump?
The incorrect, illegal answer is to just open a connection. But I'm not suggesting you do that....
Maybe you can rent an extractor pump?