mlg@akgua.UUCP (M.L. Graham [Mike]) (10/14/85)
I have a slow leak in my a/c system (Ford, factory
instalation). It looses about 1 can of freon every two
to three weeks, and I can't locate the leak. I've
cleaned all the fittings and connections and looked for
signs of oil -nothing. The evaporator doesn't freeze up,
even under continuous (8 hour) use, which makes me
think that the evaporator may be ok.
Now I have to admitt, I have gotten my money's worth out
of it. It's got 290,000 miles on it, and the a/c system
has not been touched, except to add freon every now and
then the last couple of years. Any good ways to find a
leak like this? Should I replace the compressor, assuming
that it is the most likely source? I really hate to replace
anything, regardless of age, if I'm not sure that it's
defective (that's what dealers do, in't it?).
Any advice will be appreciated.
Mike Graham @AT&T Technologies
Atlanta, Georgia
{ihnp4}akgua!mlgrmrin@inuxa.UUCP (D Rickert) (10/16/85)
> > I have a slow leak in my a/c system (Ford, factory > instalation). It looses about 1 can of freon every two > to three weeks, and I can't locate the leak. I've > cleaned all the fittings and connections and looked for > signs of oil -nothing. The evaporator doesn't freeze up, > even under continuous (8 hour) use, which makes me > think that the evaporator may be ok. > > Now I have to admitt, I have gotten my money's worth out > of it. It's got 290,000 miles on it, and the a/c system > has not been touched, except to add freon every now and > then the last couple of years. Any good ways to find a > leak like this? Should I replace the compressor, assuming > that it is the most likely source? I really hate to replace > anything, regardless of age, if I'm not sure that it's > defective (that's what dealers do, in't it?). > > Any advice will be appreciated. > > > Mike Graham @AT&T Technologies > Atlanta, Georgia > {ihnp4}akgua!mlg 290,000 MILES??? Anyway, to answer the questions, all of our local auto stores carry, for about $3.50, a can that contains a die (red) which will help you find your leak. It's standard practice in air conditioning work to use this stuff. It is also available mixed in with freon for about $8 a can or you can buy the big can from a supply house for about $25. I know, not cheap, but freon has pretty good shelf life it you have a spare shelf to store it on. Also available for about $3.50 a can is a stop-leak formulation which I have never used but may have try on my daughter's car. Any one have any experience with this stuff? -- You are Beautiful, Dick Rickert my manufactured love;- AT&T CPL but it is only Svengali, Indy, IN talking to himself again. Reward is its own virtue!
bl@hplabsb.UUCP (10/16/85)
> > I have a slow leak in my a/c system (Ford, factory > instalation). It looses about 1 can of freon every two > to three weeks, and I can't locate the leak. I've > cleaned all the fittings and connections and looked for > signs of oil -nothing. The evaporator doesn't freeze up, > even under continuous (8 hour) use, which makes me > think that the evaporator may be ok. > > Any advice will be appreciated. You can buy cans of freon that contain a red dye. It's used for cases such as this.
jeff@cucca.UUCP (Jeff Damens) (10/16/85)
In article <1735@akgua.UUCP> mlg@akgua.UUCP (M.L. Graham [Mike]) writes: > >I have a slow leak in my a/c system (Ford, factory >instalation). It looses about 1 can of freon every two >to three weeks, and I can't locate the leak. I've >cleaned all the fittings and connections and looked for >signs of oil -nothing. The evaporator doesn't freeze up, > even under continuous (8 hour) use, which makes me >think that the evaporator may be ok. > >Now I have to admitt, I have gotten my money's worth out >of it. It's got 290,000 miles on it, and the a/c system >has not been touched, except to add freon every now and >then the last couple of years. Any good ways to find a >leak like this? Should I replace the compressor, assuming >that it is the most likely source? I really hate to replace >anything, regardless of age, if I'm not sure that it's >defective (that's what dealers do, in't it?). > >Any advice will be appreciated. > > >Mike Graham @AT&T Technologies >Atlanta, Georgia >{ihnp4}akgua!mlg Don't be too quick to replace the compressor... it could just as well be a high pressure hose (which will be a lot cheaper). To find the leak, you can buy a can of freon which has a red dye in it. You add it to the system just like you would an ordinary can. You should then be able to see from where you're losing refrigerant. If you replace a hose yourself, it's a good idea to have the system evacuated to get all the moisture out of it before you charge it. Jeff Damens
ccrse@ucdavis.UUCP (Steve Ehrhardt) (10/16/85)
> > I have a slow leak in my a/c system (Ford, factory > instalation). It looses about 1 can of freon every two > to three weeks, and I can't locate the leak. I've > cleaned all the fittings and connections and looked for > signs of oil -nothing... > > ...Any good ways to find a leak like this? It should be possible to purchase a can of freon with a marking compound added that will leave a (usually red) stain wherever the stuff leaks out. Most automotive supplies seem to carry this material, at least around here. Why don't you try putting some of this stuff in and see if you can spot the leak before you try replacing any components? You might get lucky and find that it's something cheap after all....
mls@harpo.UUCP (10/17/85)
I would look carefully at the front seal on the compressor. You can buy a can of freon with red dye to add to the system to find the leak. I have never used it. Irv McNair ATT Bell Labs Whippany
dave@cylixd.UUCP (Dave Kirby) (10/18/85)
In article <132@inuxa.UUCP> rmrin@inuxa.UUCP (D Rickert) writes: >> I have a slow leak in my a/c system (Ford, factory >> instalation). It looses about 1 can of freon every two >> to three weeks, and I can't locate the leak. Some mechanics have a special electronic "freon-sniffer" that they use to detect freon leaks. This is much better than the red dye method, because it is very sensitive, and can detect leaks where you can't see (but can put the probe), such as in the evaporator core. It might be cheaper to have a mechanic check out your system than it would be to get enough dye to find it yourself. They can also pull a vacuum on it when you think you've plugged the leak. ----------------------------------------------------------------- Dave Kirby ( ...!ihnp4!akgub!cylixd!dave) (The views expressed herein are the exclusive property of Dave Kirby. Any person, living or dead, found with the same or similar opinions will be prosecuted to the fullest extent of law.)
ems@amdahl.UUCP (ems) (10/18/85)
> > > > I have a slow leak in my a/c system (Ford, factory > > instalation). It looses about 1 can of freon every two > > to three weeks, and I can't locate the leak. I've > > cleaned all the fittings and connections and looked for > > signs of oil -nothing. > > .... Any good ways to find a > > leak like this? Should I replace the compressor, assuming > > that it is the most likely source? I really hate to replace > > anything, regardless of age, if I'm not sure that it's > > defective (that's what dealers do, in't it?). > > > > Anyway, to answer the questions, all of our local auto stores carry, for about > $3.50, a can that contains a die (red) which will help you find your leak. > It's standard practice in air conditioning work to use this stuff.s ... > Also available for about $3.50 a can is a stop-leak formulation which > I have never used but may have try on my daughter's car. Any one > have any experience with this stuff? > I would not take the shotgun approach until I had proven that I could not identify the leak source. While the red dye is good for finding fast leaks, it often fails to find slow leaks of the type described. I have no experience with the stop leak goop, but that is not finding and fixing the problem; just putting a kludge over it. Esthetically unpleasing. What would I do? Go to an auto shop for an 'estimate'. Let them use there hi tech freon sniffer (detects *very small* leaks by listening for the sound it makes!) Then thinking about the repair needed. If minor, maybe let them do it. If major (like compressor) do it myself. -- E. Michael Smith ...!{hplabs,ihnp4,amd,nsc}!amdahl!ems 'If you can dream it, you can do it' Walt Disney This is the obligatory disclaimer of everything. (Including but not limited to: typos, spelling, diction, logic, and nuclear war)
levy@ttrdc.UUCP (Daniel R. Levy) (10/20/85)
In article <393@cylixd.UUCP>, dave@cylixd.UUCP (Dave Kirby) writes: >In article <132@inuxa.UUCP> rmrin@inuxa.UUCP (D Rickert) writes: > >>> I have a slow leak in my a/c system (Ford, factory >>> instalation). It looses about 1 can of freon every two >>> to three weeks, and I can't locate the leak. > >Some mechanics have a special electronic "freon-sniffer" that they >use to detect freon leaks. This is much better than the red dye > >Dave Kirby ( ...!ihnp4!akgub!cylixd!dave) I have also heard of a special propane torch head which has an attachment for a hose, used for the purpose of sniffing freon. The flow of the propane in the head past the hose attachment orifice produces suction in the hose, and you probe around with the end of the hose. The flame changes color when freon is sucked into it. I have no idea how well this works, or if it is even safe, given the possible presence of gasoline fumes. I just wished to mention it. -- ------------------------------- Disclaimer: The views contained herein are | dan levy | yvel nad | my own and are not at all those of my em- | an engihacker @ | ployer or the administrator of any computer | at&t computer systems division | upon which I may hack. | skokie, illinois | -------------------------------- Path: ..!ihnp4!ttrdc!levy
wilde@apollo.uucp (Scott Wilde) (10/22/85)
>I have also heard of a special propane torch head which has an attachment >for a hose, used for the purpose of sniffing freon. The flow of the propane >in the head past the hose attachment orifice produces suction in the hose, >and you probe around with the end of the hose. The flame changes color when >freon is sucked into it. I have no idea how well this works, or if it is even >safe, given the possible presence of gasoline fumes. I just wished to mention Aieeee!! This is something you don't want to do! The combustion products from freon are quite toxic. All that fluorinated and chlorinated stuff is bad news when you burn it. -- Scott Wilde ...decvax!wanginst!apollo!wilde
ralphd@teklds.UUCP (Ralph Durtschi) (10/24/85)
> >I have also heard of a special propane torch head which has an attachment > >for a hose, used for the purpose of sniffing freon. The flow of the propane > >in the head past the hose attachment orifice produces suction in the hose, > >and you probe around with the end of the hose. The flame changes color when > >freon is sucked into it. I have no idea how well this works, or if it is even > >safe, given the possible presence of gasoline fumes. I just wished to mention > > Aieeee!! This is something you don't want to do! The combustion products > from freon are quite toxic. All that fluorinated and chlorinated stuff is > bad news when you burn it. > -- I took a GM factory course on air conditioning repair and troubleshooting about 15 years ago. The torch and hose was the only recommended procedure for finding a freon leak. The flame burned a little blue-green with the presence of freon. I think this was before dyed freon was available. For what it's worth. Ralph
heffner@bsdpkh.UUCP (Paul K Heffner) (10/25/85)
> >I have also heard of a special propane torch head which has an attachment > >for a hose, used for the purpose of sniffing freon..... > > Aieeee!! This is something you don't want to do! The combustion products > from freon are quite toxic. All that fluorinated and chlorinated stuff is > bad news when you burn it. > My father runs an A/C-Refrigeration repair buisness (1-man) and I have been literally been fixing the stuff as long as memory serves. (It broke the old boy's heart when I became a bit flipper...) I've been following the A/C repair discussions with interest and I hope I can add some useful input. Scott Wilde was technically correct regarding the burning of F-12 in Propane as it forms Phosgene gas which is rather noxious. The leak detector device under discussion however, is not likely to produce enough (given a reasonably small freon leak as the one under discussion) to do much more than make you sneeze. As an aside, it has only been within the last decade that propane torches have taken off for general refrigeration repair use. Before that it was always acetyline torches for soldering/leak detecting which never seemed to produce any noticable smell. Regarding the use dye to find the leak, DuPont was marketing F-12 with an additive called (I believe) Dyetel. We found this far more desirable than a dye additive as the additive was suspected to corrode the copper fittings. Actually the dyes very rarely ever were of use as the freon has a tendency (spraying out under high pressure) to just dye up the whole general area and leave a mess. We had lots of luck, however, with the simplest and cheapest detector of all: Bubbles!! (Childrens soap bubbles) Bring the system up to a reasonable pressure (50-100 psi if you have gauges) and use a small brush to soak the stuff on all the joints you suspect. Even the smallest leak will produce noticable bubbles. Use a small mirror to peek behind the joints as the bubbles will appear usually at one side of the joint. Since you have been adding freon for years and not adding any oil, there's a good chance the shaft seal of the compressor is your (primary) leak as the system oil recirculates through the system and will escape along with a leak. Refrigeration oils are specially formulated for low wax and moisture content. A good mechanic will evacuate the system to remove any air which might have migrated into the system. An extremely low vacuum on your system causes any moisture to vaporize and be drawn out. He can also ( If well equipped) replace the oil (can require a special pump) Sorry to ramble on so, hope this helps.... Paul Heffner {ihnp4,akgua}!bsdpkh!heffner
svirsky@ttidcb.UUCP (William Svirsky) (10/28/85)
In article <116@bsdpkh.UUCP> heffner@bsdpkh.UUCP (Paul K Heffner) writes: > We had lots of luck, however, with the >simplest and cheapest detector of all: Bubbles!! (Childrens soap bubbles) > >Bring the system up to a reasonable pressure (50-100 psi if you have >gauges) and use a small brush to soak the stuff on all the joints you >suspect. Not just the joints. I found a leak once around the edges of the sight glass on the receiver/dryer. The sight glass is the little round window that most directions tell you to look through to check if your a/c system needs freon. Bill Svirsky Citicorp/TTI Santa Monica, CA
kitten@hao.UUCP (10/29/85)
> > I have a slow leak in my a/c system (Ford, factory > instalation). It looses about 1 can of freon every two > to three weeks, and I can't locate the leak. I've > cleaned all the fittings and connections and looked for > signs of oil -nothing. The evaporator doesn't freeze up, > even under continuous (8 hour) use, which makes me > think that the evaporator may be ok. > > Now I have to admit, I have gotten my money's worth out > of it. It's got 290,000 miles on it, and the a/c system > has not been touched, except to add freon every now and > then the last couple of years. Any good ways to find a > leak like this? Should I replace the compressor, assuming > that it is the most likely source? I really hate to replace > anything, regardless of age, if I'm not sure that it's > defective (that's what dealers do, in't it?). > > Any advice will be appreciated. > > Mike Graham @AT&T Technologies ** I have heard of a dye used specifically for this purpose. It's injected into the system like freon, I think, and aids in finding leaks. As a matter of fact, I believe they use the stuff at the dealer. I suggest you ask your local auto parts store, preferably a big one. Good luck! {ucbvax!hplabs | allegra!nbires | decvax!noao | harpo!seismo | ihnp4!noao} !hao!kitten CSNET: kitten@NCAR ARPA: kitten%ncar@CSNET-RELAY