Air Conditioner (AC) Line Inspection and Repair (1 Viewer)

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Jan 2, 2014
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PPV TEXAS
 
I have done a search and read every AC thread I could find. I have a 2000 LC with a very small leak...so small that 2 so called AC experts have done a pressure test and said it is fine.

It's not fine. After 2-3 weeks the 134a is leaking out to the point that the car will no longer cool - I live in Houston and need a cool car in the summer.

I changed out the Schraeder valves a couple of weeks ago when I saw some oil in the engine compartment. Although the changing of the inlet valves slowed the leak it did not stop it. I followed this up by cleaning the compartment thoroughly and have seen no more signs of oil - yet the leak continues.

My question is how to inspect the AC lines that run to the rear of the car behind the firewall? What needs to be removed to be able to visually inspect? Do you have to use a lift?

My service manual specifically refuses to address any AC issues for "liability issues". Any insight would be greatly appreciated.
 
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Feb 2, 2015
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SW Ohio
You can visually see all the rear AC lines by looking under the passenger side, they run along the passenger frame rail.
 
Joined
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SW Ohio
lift is helpful but not necessary depending on your size I suppose. I crawl under our LC often without a lift.

For the actual job of replacing lines, then yes, a lift would be very very helpful.
 
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Illinois
You can look for oily residue that is from the oil in your refrigerate which will escape through the leak. If you can't find oil I found my leak by adding UV dye to the system. I wasn't able to find my leak with 300psi of nitrogen in the system, found the leak almost instantly with the dye. Of course you'll need to fill the system enough to close the low pressure switch on the system to allow the compressor to engage. You can by a can of 134 that has the uv dye in it already. Get a UV light and wait for nightfall and you find the leak very quickly.
 
Joined
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Messages
961
Location
PPV TEXAS
 
You can look for oily residue that is from the oil in your refrigerate which will escape through the leak. If you can't find oil I found my leak by adding UV dye to the system. I wasn't able to find my leak with 300psi of nitrogen in the system, found the leak almost instantly with the dye. Of course you'll need to fill the system enough to close the low pressure switch on the system to allow the compressor to engage. You can by a can of 134 that has the uv dye in it already. Get a UV light and wait for nightfall and you find the leak very quickly.
The mechanic has tried both nitrogen and dye, swears the is no leak. Thanks!
 

DanInDenver

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Jun 15, 2012
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347
Location
Denver, CO
 
I have at least one and I think two pinholes in the line leading to the rear. The pin holes are in the line just under the passenger seat.
I am going to try this line splice. Any idea how these clamps are "clamped" any special tool or method to use?

Amazon product
 

flintknapper

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May 22, 2004
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8,110
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Deep East Texas
 
 
 
The mechanic has tried both nitrogen and dye, swears the is no leak. Thanks!
Then your 'mechanic' needs to reconcile WHY the unit is not cooling. Low pressure (refrigerant loss) is of course only one of many reasons.

If you put a set of gauges of the system and it indicates low pressure (high and low side) then clearly there IS a 'leak'.

Refrigerants are not consumables (like engine oil) so the ONLY way for your closed system to lose it....is by leaking it.

First thing you need to do is determine what your pressures are (establish whether or not you've lost refrigerant).

Just because someone hasn't found (seen) the source of a leak...doesn't mean it isn't there. Pin holes in the insulated portions of your lines that trace the firewall will hide leaks. Leaks at the front or rear evaporators (housed) simply can't be seen.

Get some pressure readings and we'll go from there.
 
Joined
Jan 2, 2014
Messages
961
Location
PPV TEXAS
 
Then your 'mechanic' needs to reconcile WHY the unit is not cooling. Low pressure (refrigerant loss) is of course only one of many reasons.

If you put a set of gauges of the system and it indicates low pressure (high and low side) then clearly there IS a 'leak'.

Refrigerants are not consumables (like engine oil) so the ONLY way for your closed system to lose it....is by leaking it.

First thing you need to do is determine what your pressures are (establish whether or not you've lost refrigerant).

Just because someone hasn't found (seen) the source of a leak...doesn't mean it isn't there. Pin holes in the insulated portions of your lines that trace the firewall will hide leaks. Leaks at the front or rear evaporators (housed) simply can't be seen.

Get some pressure readings and we'll go from there.
thanks for your thoughts. It was fixed a while back.
 
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Jan 2, 2014
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PPV TEXAS
 
Did they track down the source and provide insight or was it more you threw money at them til they fixed it?
Javier sent me to a guy here locally, in Houston named John @ Cool Flow 713-688-7525 who found using Nitrogen Gas and some sort of sniffer. He was really good. After a year of trying and a half dozen different “experts” he found the leak in 10 minutes.
 

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