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Tracing 134r A/C leak; take off dash to UV-see evaporator? by Jdlog
Started on: 11-29-2003 12:41 AM
Replies: 7
Last post by: Jdlog on 11-29-2003 06:50 PM
Jdlog
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Report this Post11-29-2003 12:41 AM Click Here to See the Profile for JdlogSend a Private Message to JdlogDirect Link to This Post
I've charged the system with UV tracer because I have a large leak somewhere in the A/C system. The one part I still need to see with the UV light is the evaporator area.

Is there a way to take a peek without having to take down the dashboard?

86 2.5l 5speed.

TIA

Benno

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hugh
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Report this Post11-29-2003 07:41 AM Click Here to See the Profile for hughSend a Private Message to hughDirect Link to This Post
See if you can find someone with an electronic leak detector.That will locate the leak for you without taking anything apart.If you can't see it at least you will know the area of the leak,then take thins apart if necessary.

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Electrathon
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Report this Post11-29-2003 11:55 AM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageSend a Private Message to ElectrathonDirect Link to This Post
You said this is a large leak, usually UV dye will not work well on those. The dye will not have enough time to travel through the system before the refrigerant is all gone. Depending on what you are refering to as a large leak (does it leak out in a few minutes, hours, days or weeks?) you will be much better off with ae electronic leak detector. If this leak is big then often times you can hear them when it is first charged. Another trick is to use soapy water on a suspect spot.

It is very unusual for there to be a big leak in the evaporator. Much more common is the front seal on the compressor. Also fittings and connections are common. Next would be a broken line or a condenser hole. The evaporator is about the least likely to have a large leak.

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Mark
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Report this Post11-29-2003 01:36 PM Click Here to See the Profile for MarkSend a Private Message to MarkDirect Link to This Post
The electronic leak detectors can be somewhat misleading because they will "sound off" when they sniff moisture. There may be alot of moisture in the heater/evaporator air box.

My GT had no refrigerant in the system when I bought it. Of course, I checked for leaks and was CONVINCED that I had a leaky evaporator based on the reaction of the electronic leak detector when I "sniffed" the air outlets. Not so. I took a chance and just evacuated then recharged it. The system has held the charge for over 3 years!
My suspicions were correct that the shop that did the clutch job for the P.O. opened the A/C system to drop the cradle.

Bottom line is don't be misled with an electronic detector.

If you do have a leak in the evaporator, you may be able to "see" the UV dye if you shine the light up the condensate drain.

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Jdlog
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Report this Post11-29-2003 03:25 PM Click Here to See the Profile for JdlogSend a Private Message to JdlogDirect Link to This Post
I agree with you guys. This leak dumps everything within 20 hours. I did think I may be able to hear it. The evaporator was/is not my prime suspect...the fittings and connections were. Mark, good idea about the drain hole. After that, I will have to find a good electronic sniffer to probe around like you all mention.

An observation: it takes longer to loose the gas if I use the A/C continuously. The real loss seems to happen overnight, with the car off. At first, I kept looking at the low pressure side because of this.

Thanks!
Benno

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hugh
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Report this Post11-29-2003 03:30 PM Click Here to See the Profile for hughSend a Private Message to hughDirect Link to This Post
I've been using a Detek leak detector for years with no problems having moisture affect it.It has a high and low level of detection.I use the high to get the general area of a leak and the lower level to get closer,then I use soapy water to pinpoint the leak.If the leak is really that bad,you may be able to hear it if you concentrate on it.You also need a reasonable amount of pressure in the system to do a good leak test.
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theogre
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Report this Post11-29-2003 03:38 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreDirect Link to This Post
It leaks less while running...

I think I'd start at the compressor shaft seal.

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Jdlog
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Report this Post11-29-2003 06:50 PM Click Here to See the Profile for JdlogSend a Private Message to JdlogDirect Link to This Post
 
quote
Originally posted by theogre:

It leaks less while running...

I think I'd start at the compressor shaft seal.

Yes, that is, in fact, where I started looking. There was no trace there. However, I plan to look there again -- from underneath -- because the UV light I used then was not as good as the one I have now.

Thanks, I wasn't sure if I'd go through the trouble of lifting the car again.

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