Freon Slowly Leaks Out

[guyhaz]

On my 2003 CTD the freon leaks out over a three week time period and needs recharged again. Put some Uv leak detector and tried to spot the leak with a UV light... but to no avail. Any ideas on how to find this small leak or has anyone else run across this. The entire A/C system was replaced before I bought the truck not too long ago.



Thank You!

 

[jelag]

I would first overcharge it by 10 - 12 oz... including the leak check... ... if you check the system with the engine off, the pressure will become equal on both sides of the system..... but I'm guessing that its got to run for an hour or so to work the detector around the system... I'd shut the engine down, put it someplace where it wasn't bright and I'd look closely at all the fittings first... than the seal on the compressor shaft and finally tear the dash apart for the connections to the evaporator...

Its a very small leak if it takes 3 weeks to leak off so it won't function... .

I've also found the leaks with nothing more than soap and water and a spray bottle... .

Lastly I'd find an electronic leak detector wish is much more sensitive than any of the tests I've mentioned above...

 

[Mobius1]

I would check your receiver dryer. Mine was leaking and no one could find a leak. I actually found the leak by running my hand under the R/D

 

[basilry]

I dont know if you have an intake on your truck or not but my intake wasnt positioned right and it ended up wearing a hole through the line. Just a thought

 

[guyhaz]

One more thing... the system was pressurized... leak down tested and it held pressure for the entire day. Since everything is new... I guess possibly a poor install job... Buddy has a sniffer and was going to try that... if nothing I guess pull the dash apart and look at the evaporator. I am stumped on this one... nothing is showing up in the usual places.

 

[fox]

I fooled with a durango for a year with a slow leak.

Then took it to a friend, he vacuum checked it and said it does NOT have a leak. After thinking about it over night, I realized it was one of the two schadrer valves leaking.

It was the low pressure side!

Been good all year.

 

[mwilson]

Is your engine fan engaging as it should when the A/C pressure rises (going slowly or stopped at a light)??



If it is not, then you could be losing refrigerant due to high pressure as it will bleed out thru the safety valve.



Worth checking out.



Mike.

 

[JMetzger]

It could be the evaporator leaking & to check that stick the leak detector in one of the center outlets with fan on low & not on ac. Have found a lot of leaks that way

 

[LRutigliano]

Here some likely areas to check:



1) Compressor front shaft seal. These are responsible for 50% or more the refrigerant leakage per year for a system. Very difficult to check because of the clutch being in the way.



2) Schrader valves (charge ports). Ensure the caps are installed tight. Sometimes people leave this off, but the cap is the primary seal for the schrader valve. My low side was very wet with refrigerant/oil and I got a new cap.



3) Check the liquid AC line that is between the fender and the battery on the PS of the truck. The orifice tube is located here with a joint and that area could be leaking, but would be hard to diagnose because its hard to see.



4) Check your condenser tubes for rock or rust damage. This is probably not likely because the condenser tubes are large steel tubes.



When you add refrigerant back into the system, add 2 or 3oz of Medium viscosity PAG oil too. Oil leaks out with the refrigerant. Its available in a little bottle from Interdynamics and can be installed on the low side just like adding refrigerant. This will protect the compressor and also lube the front shaft seal.