2004 Jeep Grand Cherokee...

[ShaneSimon]

Hi guys...

Was just informed the car passed the vacuum test and there’s no visible refrigerant leak to the naked eye.

I was given two scenarios...either there’s a minor leak that can’t be seen as I said (although I’m unsure how likely that is - hence why I am here)

OR

The mechanic who did the compressor replacement just didn’t fully recharge the system the last time.


I will be returning in about 500 miles as my mechanic added a dye to the system to see if the potential leak can be located.

Curious for your thoughts folks...thank you very much!

1. No leak under vacuum USUALLY indicates that there won't be a leak under pressure, but not always.
2. UV dye and a check for leaks in 500 miles is a good idea.

Much appreciated. Hopefully it’s behind me. We’ll see in a couple weeks.

[ShaneSimon]

Hello again guys...

The recharge had been holding up well...definitely more than the usual two week period that I’ve read about after getting it done...

I’m just starting to notice now...about 6 weeks or so after the recharge I’m noticing the temperature gradually increase depending on conditions...So I’m most positive there is a leak somewhere...

I really don’t feel like buying a leak detector for $30 or taking it to the shop to spend unnecessary money...

If I was going to run a leak sealer through the system should I add refrigerant beforehand or just after to make sure the low side port doesn’t doesn’t get sealed...

THANK YOU!

[JohnHere]

I agree with everything that Tim and Cusser said, especially about the leak. If you live in the Northeast where most towns and cities use tons of salt on the roads to melt snow and ice, you might have a pinhole leak in a hard line due to corrosion, which in turn would cause a slow loss of refrigerant. Since this is a 15-year-old vehicle, I'd look very closely at the hard lines down low where they're more susceptible to road splash, like near the bottom of the radiator and radiator support. Also check carefully for the presence of any oil in the same area. Sometimes, a refrigerant line crossing from one side of the vehicle to the other, way down there, will be wrapped in foam insulation, making it even harder to identify a leak. Check the insulation to see whether it's oil soaked. If so, refrigerant will be leaking out of the line as well.

[JohnHere]

DEFINITELY DON'T ADD ANY SEALER TO THE SYSTEM. Doing so will only create more very costly problems. Find the leak, repair it, evacuate and recharge the system, and you'll soon be driving in cool comfort again.

[Cusser]

DEFINITELY DON'T ADD ANY SEALER TO THE SYSTEM. Doing so will only create more very costly problems. Find the leak, repair it, evacuate and recharge the system, and you'll soon be driving in cool comfort again.

As to what JohnHere posted: read, re-read, and follow every word of that !!!

Never add sealer or refrigerant containing sealer. Some UV dye is OK.