Re: [DML] finding freon leaks

["jtrealtywebspannet" <jtrealty@xxxx>]

Using leak detectors on automotive systems is very hard. With all the 
air moving over the parts it is hard to use them. The best ways are 
either with a leak detector dye or the best thing that I like is a 
leak detector solution of soapy water with a little glycerine. You can 
also find many leaks by the traces of refrigerent oil left behind from 
the leak. The hardest leak to find is the compressor seal. The hoses 
being so long and being porous are the largest source of small leaks. 
If you find you are always adding Freon then once in a while you MUST 
add some refrigerent oil. Most servicemen never think of touching the 
oil, they just squirt some Freon in, charge the customer the "big 
bucks" and wait for him to come back next year. Some of this is out of 
ignorance in how to properly service A/C systems and part is the 
chance for repeat business. Cerified mechanics are supposed to fix any 
leaks over 1/2 OZ per year but it is faster and easier (and more 
profitable) to just shoot some Freon in. One of the symptoms of a 
malfunctioning A/C system is some loss of capacity. This doesn't mean 
it won't blow cold air, it means on the hotest days it doesn't seem to 
cool off the car like it used to when it was new. The causes can range 
from dirty evap or condenser coils to low refrigerent to contamination 
in the system.
BTW the sparking in the leak detector is safe to use in a combustable 
atmosphere. If you want to talk about unsafe use a halide detector 
that fits on a propane torch and uses a copper reaction plate. That 
thing if it found Freon would combust it and create Phosgene gas.
David Teitelbaum
vin 10757 



--- In dmcnews@xxxx, "Walter Coe" <Whalt@xxxx> wrote:
> I've been going through the archives reading everything I can find 
on a/c
> evaporators because I'm getting ready to replace mine. I came 
across a
> thread I started last year about finding freon leaks and now that I
> understand the situation better, I'm going to answer my own post 
with a
> warning to not blow yourself up.
> 
> Freon leak detectors are sensitive to a variety of hydrocarbon 
molecules
> including gasoline. The situation with the DeLorean is unique 
(isn't it
> always?) in that the condensate drain is right next to the fuel tank 
where
> heavy fuel vapors will linger in the cavities in and around the 
frame.
> Considering that I had a defective TankZilla, there were plenty of 
fuel
> vapors making my leak detector think that the whole front of the car 
was a
> freon leak. And another thing I didn't know at the time is that 
these
> detectors work by monitoring a high voltage discharge in the 
sensor's tip.
> This spark can ignite fuel vapors, so it wasn't such a bright idea 
for me to
> go sticking the thing around the fuel tank.
> 
> Walt (taking pride in my humility)
> 
> > I am trying to locate a leak in my a/c system and am having some 
trouble
> > doing it. I just bought a leak sniffer from NAPA and put it to 
work. So
> > far I seem to be finding a high concentration of CFCs between the 
frame
> and
> > the fuel tank near the point where the flexible fuel lines meet 
the metal
> > fuel lines.
> <snip>