Ok Gang... I need to pick someones brain... I've got a pretty good leak in the A/C system for it to leak out all pressure to 0 PSI in about 2 weeks. I've got a dye pack in the system but haven't noticed the green tint oil anywhere yet. I'm thinking of grabbing a single can of R134a and add it to the system for pressure and black light the whole thing again... Any ideas or suggestions?

Get a spray bottle and mix up some dish detergent and water. Get some pressure in the system and start spraying. Also make sure you check the compressor where the clutch is. Another thing you can do is put another can of R-134 in it and use a refrigerant leak detector. That way you can also check the drain and see if there is any refrigerant there. If there is the evap is probably the source of the leak.

Thanks for the soap idea... I'll give that a shot... As for a freon sniffer I don't have one... But the evaporator is brand new I installed it this spring...

I would check all those fancy hose connections that you have to have a special tool to remove. My ford liked to rattle those around.

I'm thinking about getting a o-ring kit and just redo the o-rings in the system... The only thing else is to soap the compressor and check it for leaks...

I'm thinking about getting a o-ring kit and just redo the o-rings in the system... The only thing else is to soap the compressor and check it for leaks...

FYI - I just had my highpressure line replaced, my heatercore/evaporator replaced behind dash and all charged back up .......... leak - same as you . The place I had it done said it was a bolt on the rear of the compressor. I didn't see it as wife took it in - but she says she saw the die. So another place to check ....... soap /die etc. friggin frustrating .........

Mine was at the high pressure cutoff switch near the bottom of the truck, and another at the compressor seal.Good luck they can be anywhere.

The most common way to find a hard to find leak is to use air pressure. We usually use nitrogen as you can get more pressure inside the system but air works ok too. If it is a good leak 120 psi shop air with a regulator adapted to the charge fittings will find a leak but most times it takes about 150-250 psi to find the leaKS YOU DESCRIBE. which is why we use nitrogen as the nitrogen compressor will go to over 4000 psi.

I had the same though of just pressurizing the system with compressed air and soaping the system also looking for the funky green dye with black light... I do the black light first before the soap to prevent washing the dye off.

The most common way to find a hard to find leak is to use air pressure. We usually use nitrogen as you can get more pressure inside the system but air works ok too. If it is a good leak 120 psi shop air with a regulator adapted to the charge fittings will find a leak but most times it takes about 150-250 psi to find the leaKS YOU DESCRIBE. which is why we use nitrogen as the nitrogen compressor will go to over 4000 psi.

If you even attempt to go to 4000PSI Make sure I am not anywhere close!!!! Anything over 250 psi is dangerous for the hoses and compressor seal.

If you even attempt to go to 4000PSI Make sure I am not anywhere close!!!! Anything over 250 psi is dangerous for the hoses and compressor seal.

LOL.............. I was just saying what a nitrogen compressor is capable of.

Well... I hooked up the manifold gauge shot about 100 PSI in the system fire the compressor for a short while to stir the dye oil around to give me a wet spot that is fresh. I black lighted everywhere on the system and found nothing. So the next step was to look for phyiscal damage. I found some... Well I feel like a horses ... I kept a piece of hardware mesh in found of the radiators for years helping keep the bugs and debris out of the coolers and radiators. On the lower left corner as you face the condenser you can clearly see where the hardware mesh had been rubbing the condenser main tube. So I'm going to break out with JB weld and patch it for now and see if that might of been the cause. I'm still going to pressurize the system again and soap it when it a bit warmer today... But This is what I found so far...

Well... I hooked up the manifold gauge shot about 100 PSI in the system fire the compressor for a short while to stir the dye oil around to give me a wet spot that is fresh. I black lighted everywhere on the system and found nothing. So the next step was to look for phyiscal damage. I found some... Well I feel like a horses ... I kept a piece of hardware mesh in found of the radiators for years helping keep the bugs and debris out of the coolers and radiators. On the lower left corner as you face the condenser you can clearly see where the hardware mesh had been rubbing the condenser main tube. So I'm going to break out with JB weld and patch it for now and see if that might of been the cause. I'm still going to pressurize the system again and soap it when it a bit warmer today... But This is what I found so far...

I think I would be looking for a used one in a junk yard, I don't have much faith in any epoxy product.

Problem no wrecking yards near me... Well there is Riggins but there is nothing there for Dodge's... Next closest good wrecking yard is 180-200 miles away...

If you use epoxy, make sure you get the metal roughend up so the epoxy can get into the pores and bond. Roughend as in like using 320 grit paper.Use a good cleaner like brake clean or some acetone to clean the surface. I would rather use acetone that is what we used when i did that type of work for Douglas Aircraft Company.Cyclohexane is the best but most don't have it. If you do use Cyclohexane Keep it off your body it is a cycle solvent and it is addictave like a drug. I saw a guy at work that was super addicted to it.It being a cycle solvent goes right thru the pores of the skin, but is a hell of a cleaner. Effects on Humans: Cyclohexane is an irritant of the eyes and mucous membranes in humans. By analogy with the effects in animals, exposure to high concentrations is expected to cause narcosis. Exposure to 300 ppm caused irritation to the eyes and mucous membranes in workers [Hathaway et al. 1991]. Exposure to higher concentrations is likely to cause dizziness, nausea, and other narcotic effects. On repeated contact, cyclohexane is a defatting agent. Cyclohexane has not been shown to cause the hematologic changes associated with exposure to benzene

Any new developments here?

Well I stopped in the local NAPA sotre and order a set of O-rings for $10 and proceeded to replace all the o-rings in the system. Be aware there is 1 O-ring missing in the kit for the condenser up front so remember to pul it and take it with you for size. Re-assembled everything and place a vacuum on it and it held for at least 20-30 minutes while I did other things like straightening all the condenser fins. So since it held a good vacuum I figure its time to toss my last 3 cans of freon at it and hope for the best.

Well I stopped in the local NAPA sotre and order a set of O-rings for $10 and proceeded to replace all the o-rings in the system. Be aware there is 1 O-ring missing in the kit for the condenser up front so remember to pul it and take it with you for size. Re-assembled everything and place a vacuum on it and it held for at least 20-30 minutes while I did other things like straightening all the condenser fins. So since it held a good vacuum I figure its time to toss my last 3 cans of freon at it and hope for the best.

and compressor oil! I hope it works for you!

So far the second ride out and about 4 days after the repair and still holding good cold A/C. So now I change all O-ring except 1 at the condenser and the 2 on the back of the compressor. The evaporator is new this spring. So I think I got it all covered for now...

Just a side note about vacuum on the system, I have seens many many systems with slow leaks that hold a vacuum for infinity but add pressure to the system and it will be dead in a few days or less. So do not trust your system based on a vacuum test alone. It will let you know if there is a big leak but won't help on the small ones. As far as adding oil to the system................Don't do it unless you replace a lot of components at the same time or blow a high pressure hose and it blows a lot of oil oit when it blew, the compressors come precharged with all the system should need to operate great. Too many times people add too much oil and then have a poor performing ac system as the freon capacity has diminished.

Just a side note about vacuum on the system, I have seens many many systems with slow leaks that hold a vacuum for infinity but add pressure to the system and it will be dead in a few days or less. So do not trust your system based on a vacuum test alone. It will let you know if there is a big leak but won't help on the small ones. As far as adding oil to the system................Don't do it unless you replace a lot of components at the same time or blow a high pressure hose and it blows a lot of oil oit when it blew, the compressors come precharged with all the system should need to operate great. Too many times people add too much oil and then have a poor performing ac system as the freon capacity has diminished.

Thanks for the tip on the vacuum test... As for the oil... I learn my leason long ago about buying freon with a oil charge over time it will flood the system with oil and like you said decrease the performance. So very true... To empty the system of oil might be a bigger PITA that most think...