A/C Leak Finding question

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Jul 29, 2016 | 02:12 PM

Kdeman1

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From: Troy Michigan

A/C Leak Finding question

Hello! I am rebuilding my 1987 Corvettes A/C, but I had a pretty simple question. I thought to find the leak in my system, I would clean all the connections and add oil with dye to the system. The Compressor doesn't work so what im wondering is if this will work, because I cant cycle the A/C on an off first. I have a new compressor but I wont be putting it on until I have the leak fixed its been vacuumed... So does this approach have any merit? Thanks !!!!

Jul 29, 2016 | 02:24 PM

Hoser

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Without pressure I don't think that will work. Did you try pulling vacuum on the various sections with a mighty vac (you'll have to fab a few rubber "corks" from the Home Depot collection). I did that and found it at least gave me a fighting chance at isolating the leak. That's how I found that my brand new 4 Seasons compressor leaked.

Jul 29, 2016 | 04:47 PM

Patsgarage

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From: Outside the Quick Stop N.J.

You can "charge" the system with nitrogen along with the dye, and any leaks should show up. I am not sure what the recommended test pressure is for a C4, I can usually find most leaks with 150 or so psi.

Jul 29, 2016 | 04:56 PM

Joe C

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(my 2-cents, FWIW) -- assemble the system, compressor and all, with specified amount of oil. pull a vacuum for a minimum of 30 minutes. if it holds, you're good to go - if not, there are not that many O-ring connections that could be leaking. never though about the N2 thing, but then again, I don't have access to a tank of nitrogen. once it's leak free, pull the vacuum for about 4 hours, and then add your Freon -

Jul 29, 2016 | 05:26 PM

Goldcylon

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From: Peoria Arizona.. Resident Gold Cylon

Quote:

Originally Posted by Joe C

Best reply yet, Make sure you use that dye that glows with a blacklight. Makes finding the leak easier than regular dye. I use one of those blacklight flashlights you use to look for scorpions.

Last edited by Goldcylon; Jul 29, 2016 at 05:26 PM.

Jul 29, 2016 | 09:03 PM

Joe C

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Quote:

Originally Posted by Goldcylon

Best reply yet, Make sure you use that dye that glows with a blacklight. Makes finding the leak easier than regular dye. I use one of those blacklight flashlights you use to look for scorpions.

- bought this on-line - worked perfectly. had some dye on an old rag - hit it with the UV flashlight, and it lit up like a Christmas tree -

http://www.toolpan.com/Mastercool-53...FQasaQodd-4Ixw

Last edited by Joe C; Jul 29, 2016 at 09:06 PM.

Jul 29, 2016 | 10:57 PM

GaryDoug

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From: Tampa Bay area Florida

I had good luck using this detector, Signstek S42 Refrigerant Halogen Gas Leakage Detector: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It found the Freon residue at the evaporator without running anything or installing any dye. Of course, it will always show residue at the service ports, so it may not help find a leak there unless you clean it off and try again later after using the ac.

Last edited by GaryDoug; Jul 29, 2016 at 10:58 PM.

Jul 30, 2016 | 01:44 AM

Ziggy*

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From: Proctor WV

Here we go....Is you system still R12? or monkey rigged over to 134 from store bought junk? NEED to know.....You can't mix the two...You're going to spend some money on parts to do it right....ziggy