A/C How can this be?
Thread Starter
Racer
Joined: Sep 2002
Posts: 337
Likes: 2
From: New Orleans La
A/C How can this be?
I lose freon quickly but show no leak when I vacuum the system.
I can see using dye that it shows up around the connections to the accumulator but before I changed the O rings I thought I'd
try some A/C stop leak first.
I added the stop leak and a can of 134A
and the gauges were reading properly so off I went with nice cold A/C.
Within twenty minutes the cold air stopped and the light on the auto was blinking which
meant I was Low on freon. I ordered a new accumulator which comes in in the morning but for grins I did a vacuum check and after 1 hour and 30 min the needles haven't moved off the pegs. How can I be losing freon if the system is not showing any leaks?
I can see using dye that it shows up around the connections to the accumulator but before I changed the O rings I thought I'd
try some A/C stop leak first.
I added the stop leak and a can of 134A
and the gauges were reading properly so off I went with nice cold A/C.
Within twenty minutes the cold air stopped and the light on the auto was blinking which
meant I was Low on freon. I ordered a new accumulator which comes in in the morning but for grins I did a vacuum check and after 1 hour and 30 min the needles haven't moved off the pegs. How can I be losing freon if the system is not showing any leaks?
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
If no AC oil residue on the system firewall forward the evaporator is suspect.
Suggest having the system leak tested with an electronic leak detector they are a bit more sensitive than the vacuum loss method & will pinpoint where the leak is at.
Suggest having the system leak tested with an electronic leak detector they are a bit more sensitive than the vacuum loss method & will pinpoint where the leak is at.
Thread Starter
Racer
Joined: Sep 2002
Posts: 337
Likes: 2
From: New Orleans La
Well, I'm going to change the accumulator because that's where the dye showed up even though it was changed along with the compressor.
I left the gauges on all night and they were still on the pegs!
I'm thinking when you have a vacuum on the system the o rings are being pulled in but when there is pressure (freon) on the system the o rings are pushed the other way.
I don't know!
I'm just tired of putting freon in it!
guess the electronic sniffer is next if this doesn't work.
thanks for the info!
I left the gauges on all night and they were still on the pegs!
I'm thinking when you have a vacuum on the system the o rings are being pulled in but when there is pressure (freon) on the system the o rings are pushed the other way.
I don't know!
I'm just tired of putting freon in it!
guess the electronic sniffer is next if this doesn't work.
thanks for the info!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Good chance it is your fill valve easy to change with the right tool. Will not loose freon. And sure you see the dye there but just expect it. Try this low tech test. Put spit in the valve and look for bubbles.
Last edited by antfarmer2; Aug 26, 2016 at 10:14 AM.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
If your loosing a full system charge in as little as 20 minutes, you have a gross leak. large enough to blow bubbles with a soapy solution applied.. 
the problem with both a dye, or a bubble inspection is you can't access all of the possible areas, yet with an HALON leak detector you can sniff around the discharge vents and hidden spots. This may tell you something. Leak testing is a bit of an art that takes a little bit of patience and practice.
first step: is looking the entire system over carefully for signs of oil residue or dye, the next step would be; by mixing a solution of dishwashing liquid and water, spray this over as much of the system as you can access and look for bubbles.. if all that fails then it's time for the sniffer.
keep in mind each and every time you loose Freon, you also loose a little bit of lubricant as well..
Stay away from the stop leaks!!
the problem with both a dye, or a bubble inspection is you can't access all of the possible areas, yet with an HALON leak detector you can sniff around the discharge vents and hidden spots. This may tell you something. Leak testing is a bit of an art that takes a little bit of patience and practice.
first step: is looking the entire system over carefully for signs of oil residue or dye, the next step would be; by mixing a solution of dishwashing liquid and water, spray this over as much of the system as you can access and look for bubbles.. if all that fails then it's time for the sniffer.
keep in mind each and every time you loose Freon, you also loose a little bit of lubricant as well..
Stay away from the stop leaks!!
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
