Help to ck AC for leaks - Atlanta?? - Page 3 - PeachParts Mercedes-Benz Forum

leathermang · #1 09-02-2016, 10:49 PM

Quote:

Originally Posted by 83240D

Yes it does.. Watch the condensate as it drips from the cars drain.. It will be dyed if there is a leak. Also, you can remove the blower, or other parts of the hvac unit and get a bore scope camera into the evaporator core and inspect.

I just recently correctly diagnosed a ML350s leaking core with condensate monitoring. Glowed green in UV light.

Jees guys....just delete my user acct. Get me outa here. Im done here

The system is NOT producing cold air... where are you going to get condensate produced from ?

tyl604 · #2 09-02-2016, 11:07 PM

Ok, so we are back to my post #1. I need to pressurize the system and see if it leaks. Use N2 and no need for dye.

Got that. Just trying to figure out how to do it. Pep Boys said $61 to do a leak test. Then, after I questioned them more closely, they admitted that they just pump in R134A and see if it leaks out. Could not help me because I have R12.

My indy will not pressurize it. So I am still looking for someone and hoping I do not have to do it myself.

Not in a hurry. It has not produced cold air for about 3-4 years and summer is about over in Atlanta.

Not sure where the comments about Freeze12 came from; I never contemplated doing anything with Freeze12 (unless it is also called R22).

#3 09-02-2016, 11:13 PM

Then if its not producing cold air, why are we looking for leaks instead of addressing the cooling part?

Add 1 ounce Freon to do audible check, if nothing heard, then
Fill system to full capacity with Freon. EPA allows a minor amount of leak for gauge connecting, and leak detecting. Then you get cold air.

I diagnose will full capacity of FREON. If it wont cool at that point, youve got more problems than a leak.

Once leak is found, promptly evacuate system and repair

#4 09-02-2016, 11:18 PM

Im going to put my money where my mouth is.

$500 cash says I could have this guy up and going 3 times faster than you.
No B.S. about FSMs and other hogwash.

Plain and simple.

I promise

If I lived near him Id help him out

While you were busy reading engineering notes, Id have him cooling and out the door, I do this almost daily in summer months.

leathermang · #5 09-02-2016, 11:20 PM

Quote:

Originally Posted by 83240D

Then if its not producing cold air, why are we looking for leaks instead of addressing the cooling part?

Add 1 ounce Freon to do audible check, if nothing heard, then
Fill system to full capacity with Freon. EPA allows a minor amount of leak for gauge connecting, and leak detecting. Then you get cold air.

I diagnose will full capacity of FREON. If it wont cool at that point, youve got more problems than a leak.

Once leak is found, promptly evacuate system and repair

It is not producing cold air because the refrigerant has leaked out.
Are you using the word ' Freon' to mean R12 ?

leathermang · #6 09-02-2016, 11:17 PM

Freeze 12, Duracool, and other things like that come out of the woodwork without provocation... We used to have people we knew were selling those products... Redfox, Diesel Giant, etc... so we could figure out why they posted ONLY the good claims ... never any of the true physics in their posts... kept me busy several years....
Anyway... this physics discussion served the purpose of ' bumping ' to the top anyway.. THIS may not be a good weekend to expect someone to see the post.. many have gone out of town for a last Hurray before school ties them down...

#7 09-03-2016, 12:25 PM

Quote:

Originally Posted by tyl604

Anyone in Atlanta who can pressurize my AC to see if I have leaks? My indy does not even fool with R12 anymore. I am considering shooting in some of my three cans of freon. Probably should not do it if I have a leak. 1981 300SD

Thx.

I see it that your system is probably empty. Go ahead and connect your fill valve and shoot in a small amount. then close off the valve. Listen for any large leak. If nothing heard, then perform visual inspection with soapy water in a spray bottle. Spray all fittings, rubber portions of lines, condenser, and compressor main shaft for leaks.

Your car holds 2.86 lbs, or aprox. 46 oz. r12 . You will have to determine your can size and what not to get the right amount. Fill the system, when you get close to the right amount, your inspection window will go from cloudy white, to clear(with AC running) Combining the window observation, with proper track of how much youve put in, you wont over charge it this way.

Now it should cool. If it leaks fast, soapy water will find it.

If you are worried about EPA violations, you might want to have your system converted over to r134a, as it is commonly bought at most stores.

If the EPA was worried about leaks, then over the counter r134a would be ILLEGAL

Because what does the common consumer do when they have a slow leak... refill, refill, and refill, leaking it all to the atmosphere. Yet you can still buy can after can after can....

EPA and what not is your business. If I were a DIY, I would care less about it. They arent going to spend $15k dollars to send a team out to investigate one car being filled with refridgerant.

I am not advocating breaking the law. I am simply saying, your business is your business. Do what you feel is needed on your car. it is YOUR car, and YOUR choices

tyl604 · #8 09-03-2016, 07:45 PM

I have three 1lb cans of Freon. A friend has a set of gauges. So you think I should put say a half can in, stop, then listen for a leak. Could the leak be loud enough that you could actually hear it over the sweet sounds of the diesel engine?

If you will reread the "history" post you will see that I filled it up completely about four years ago, drove it home. But it did not cool very well and mysteriously the engine got way hot - almost into the red - on the way home. So much that I had to turn on the heater and dump some heat. Has never happened even once before or since. Do not see what adding freon could have to do with it almost overheating.

Watching UGA play NC now so distracted.

leathermang · #9 09-03-2016, 09:56 PM

I have no idea why your car might have overheated that time... sometimes single random events do happen ... perhaps a thermostat stuck ... a wild guess..

On the ' hearing the leak '.. no ... certainly would not risk R12 on that kind of attempt.
The blower motor pushing air across the evaporator would drown out that small sound.

It did not cool very well on the way home..

but after that... did it do ok for a certain amount of time ?

If it did not ever cool properly in this amount of time... then it is even more important that you start with the basics and be sure everything it up to snuff as you go...

Since you are the original owner.... can you describe over the life of the car the periods which it did cool properly ? Have you ever cleaned the fins on the evaporator ?

tyl604 · #10 09-03-2016, 10:04 PM

Wow; let me think. AC went out and was replaced maybe 2000; I bought a unit and replaced it myself. Took it to the indy and he vac'd it out and put in freon. Worked for years perfectly just like new. Maybe 2010 it stopped putting out cold air and I saw bubbles in the sight glass. Went to a forum member who had gauges and freon. We installed the exact pressure of freon at the forum member's house but it did not cool nearly as much as it always did before. I decided not to have him add more freon even though we discussed it - considered a bit more because it was not really cooling much. Will take a look at the fins; have never thought about cleaning them.

As best I can remember it never cooled very well after I put in that freon and then about four months later came winter. Did not use the AC for a while. The next late spring probably it had run out of freon. I have not added any freon since.

funola · #11 09-06-2016, 09:44 AM

Quote:

Originally Posted by tyl604

Wow; let me think. AC went out and was replaced maybe 2000; I bought a unit and replaced it myself. Took it to the indy and he vac'd it out and put in freon. Worked for years perfectly just like new. Maybe 2010 it stopped putting out cold air and I saw bubbles in the sight glass. Went to a forum member who had gauges and freon. We installed the exact pressure of freon at the forum member's house but it did not cool nearly as much as it always did before. I decided not to have him add more freon even though we discussed it - considered a bit more because it was not really cooling much. Will take a look at the fins; have never thought about cleaning them.

As best I can remember it never cooled very well after I put in that freon and then about four months later came winter. Did not use the AC for a while. The next late spring probably it had run out of freon. I have not added any freon since.

What exactly was replaced "maybe 2000" "I bought a unit and replaced it myself"?

Was that the year 2000 or was the cost $2000?

If you are interested in learning AC, DIY. Otherwise, find a shop that will deal with R12. I suspect you will have to look hard to find one.

Edit: Is that indie still in business?

leathermang · #12 09-03-2016, 10:14 PM

So, What exactly did you do or not do when you replaced that ' unit ' ?
did you flush the old oil out ?
Yall installed the exact amount according to pressures.... or you measured the amount of R12 installed ?
Excess oil can degrade the cooling of the system....
the fins on the evaporator usually get bad slowly over time ( do you have a dog ) ... but if they are dirty... and you should look at some of the latest pictures of how bad they can be... then if you got too much oil in the system... the combo can result in less than OK cooling...

tyl604 · #13 09-03-2016, 10:27 PM

Replaced the AC and the receiver dryer. No idea about oil; the indy charged the unit up and it cooled like new for years. Then it ran out of freon; over what period of time I do not remember. Waited some four years then...with the forum member, we put the gauges on and installed freon until the pressure came up to speed. We were running the AC (as I remember) on full blast and max cool and I was holding it at a fast idle. It just did not get very cool and we stopped adding freon per the gauges. Never added more oil after I put in the new AC in about 2000.

No dog.

leathermang · #14 09-03-2016, 10:32 PM

So you , as far as you know, did not address the oil in the system... one way or the other ?
Add new oil ? put new receiver on ? that sort of structural stuff ?
Stopped ' per the gauges ' ... do you remember what the pressures were ?

tyl604 · #15 09-03-2016, 10:45 PM

Do not remember pressures. Did nothing with oil. Replaced AC and receiver dryer 16 years ago.

I guess it is an R4 unit but was exactly what I had when I bought the diesel. It was a single unit that I just bolted in underneath the motor after dropping out the old AC; except for removing the belts, it was really easy. After that I thought I could do it again in about an hour or two - surprised how easy it was. Do not really remember where the receiver dryer went but I replaced it too as I remember. Worked for some ten years before freon ran out.