A/C leak & empty, safe to jump + recharge dye?
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 20
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
So I have a leak on my AC system, I no it's in the engine because I heard something leaking air the system got leaned on and a line must be giving out somewhere.
the clutch is not turning on because it's completely low on Freon. can I safely jump the clutch and add a recharge dye kit and see if I can find the leak?
1999
the clutch is not turning on because it's completely low on Freon. can I safely jump the clutch and add a recharge dye kit and see if I can find the leak?
1999
Last edited by 4x4jeepmanthing; Apr 29, 2018 at 07:14 PM.
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 20
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
added two cans, no pressure built up, nor can i see anything leaking. the ac accumulation canister seems to have a leak at the top. old dye seems to be on this area so i think i might try replacing this first.
if the system is not holding a charge from the cans, am i simply able to disconnect the old accumulation canister and install a new one?
is there more ide need to do?
if the system is not holding a charge from the cans, am i simply able to disconnect the old accumulation canister and install a new one?
is there more ide need to do?
Seasoned Member
Joined: Dec 2014
Posts: 419
Likes: 12
From: Oregon (Wetside)
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0l
If you going to open the system and replace accumulator you might as well get the oring kit and just replace them at this time. I would get your hands on a vacuum pump and make sure it will hold pressure before throwing freon at it, should vacuum anyways if you open system. I believe a 30hg vacuum held for an hour or so you should be good to go.
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 20
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
Tried two cans. Can't see dye anywhere, and the can shows no pressure when injecting the Freon, nor when the trigger isn't pulled.
Ac on full and the ac clutch jumped to get it to take the casns, why wouldn't I be able to see a leak?0
Ac on full and the ac clutch jumped to get it to take the casns, why wouldn't I be able to see a leak?0
Last edited by 4x4jeepmanthing; Apr 29, 2018 at 10:17 PM.
CF Veteran
Joined: Aug 2008
Posts: 6,588
Likes: 495
From: Chico, CA
Year: 1986
Model: Cherokee
Engine: 4.3L with headers and full 3" exhaust system
I assume you are using R134A in your system. When you charge with it, the can should be upside down. It is a blend and the lighter stuff will evaporate off and the liquid will stay in the can if you charge with it right side up. If you charge upside down, one can entering the system will be enough to close the switch on the low pressure safety switch. So here is a question for you. Is there air in this system? If so, it needs to be evacuated and start over. Also look for telltale oil stains around the fittings or clutch face. If you find them, that is where your leak is
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 20
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
How can I tell if there is air in the system?
is there any danger of me jumping the clutch to let the system run?
I assume ide have to have a shop evacuate any sir as that probably not a renewable tool.
I know the leak is not by the pump because I heard it leak when reinstalling the Trans dipstick, I leaned somewhere on the ac lines and it began to purge. I assume that's why it's not showing or holding charge?
is there any danger of me jumping the clutch to let the system run?
I assume ide have to have a shop evacuate any sir as that probably not a renewable tool.
I know the leak is not by the pump because I heard it leak when reinstalling the Trans dipstick, I leaned somewhere on the ac lines and it began to purge. I assume that's why it's not showing or holding charge?
CF Veteran
Joined: Aug 2008
Posts: 6,588
Likes: 495
From: Chico, CA
Year: 1986
Model: Cherokee
Engine: 4.3L with headers and full 3" exhaust system
If you actually did hear it leak off, there is no way it will hold a charge and probably does have air in it. Having air in them makes them not work. Yes you can jump the clutch, but just putting some refrigerant in it should make it kick on too
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CF Veteran
Joined: Aug 2008
Posts: 6,588
Likes: 495
From: Chico, CA
Year: 1986
Model: Cherokee
Engine: 4.3L with headers and full 3" exhaust system
Hate to be the bearer of bad news, but I think you put a crack in the evaporator core. That explains why you cannot see the dye. It is inside the HVACf housing under the dash. I think you are going to have to pull the dash on this one
Senior Member



Joined: Sep 2015
Posts: 940
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From: Abysmo, NJ
Year: 1999
Model: Cherokee
Engine: 4.0
Thread Starter
CF Veteran
Joined: Jun 2016
Posts: 1,011
Likes: 20
From: CO
Year: 99
Model: Cherokee (XJ)
Engine: 4.0
i dont have access to the sniffer nor do i think its a rental item. could i add compressed air or vacuum test lines some how to check for a leak, hopefully hear it?


