I had the A/C system recharged with dye added three weeks ago ($177.00).

It worked great, but now the refrigerant has completely leaked out. No dye is visible, so my mechanic is figuring it is either the condenser or the evaporator.

I'd rather not rip out the dash in this heat and would prefer to add a can of 134a every other couple of weeks for the next month or two. Also, I'd prefer to not pay $177.00 to add 134a if it is reasonable to do it myself.

My WalMart 134a gauge is showing high pressure and is not taking the 134a. I picked up a manifold from Harbor Freight yesterday, and the gauges are showing no change at the static pressure test or the performance test.

Any thoughts/suggestions?

 

Find and fix the leak. If the R134 is leaking out, that means air and moisture are able to leak in. You do not want air and moisture in the A/C system. Fix it right and you will actually save money. Find a new mechanic, $177 is pretty steep for nothing more than an evac and recharge.

 

To be honest with you I'm a little confused. If, as you say all of the refrigerant has leaked out then even a cheap gauge should show no pressure.

Did you put a U-shaped wire into the low pressure switch to jump it and force the compressor to run (engine running AC on recirculate) when you attempted to charge the system?

Any good mechanic that works on AC will have a very powerful UV light that will show even a microscopic speck of dye. I found a great 51 LED light on Amazon for ~$20. You might have to pull the grill to thoroughly check the condenser. And if there is no dye there I'd look into the HVAC box drain for evidence of dye (evaporator).

Even with a set of manifold gauges hooked up the compressor needs to be running/cycling to get your low and high side pressures.

 

Thanks for the feedback. It is confusing to me as well.

No, I did not jump the low pressure switch. Where is the switch located, and what do gauge wire do I use to jump it? Also, should the wire be insulated?

And just to be clear, I have everything hooked up and running (A/C on Max recirculate with the windows open) and then jump the low pressure switch?

 

It's going to be in the A/C line going to the evaporator, on the engine side, usually near the oil filter.

You'll see a cap with 2 wires coming out the top. Pull that off and jumper into the holes with either the same gauge wire or a paper clip.

This is the low pressure switch. Jumpering will force the compressor to run. Hook up your gauge and start the engine and A/C. Don't do this for very long.

$100 evac & recharge labor plus about $60 in freon and dye + tax wasn't too high to pay the first time.

But you need to go back to the same shop and tell them what happened before you dive too deep in it yourself.

 

more than likely the leak is in the evaporater so the place to look for the dye would be in the drain tube for the evaporater.. You should be able to see it, just below the the far right side of the firewall in the engine compartment.....if I had a picture available I would post it up for you

 

Why do you think the evaporator is the likely problem?

 

I jumped the low pressure switch and the compressor engaged. The 134a did not go into the system though. Is it possible that the refrigerant level is so low that the pressure precludes the refrigerant's entering the system?

Should I have the system evacuated and then add refrigerant?

 

As I said earlier, you need to go back to the shop you have already paid to have your A/C work.

Because it doesn't.

 

condenser is easy to see and check with or without the light, evap is enclosed and unless you have a "sniffer" you can't see any signs other than the drain tube , oh and 30 plus years of practice....LOL



P.S. Take it back to the original shop as suggested and let them check it over.

 

In my 45 years experience, I've never had to replace an evaporator. I find it is usually the compressor, hose, fitting, fill valve, or O-ring. One condenser, but that system had been open for a long time and it was corroded.

 

For the price of a recharge kit --

http://www.ebay.com/itm/Freon-CFC-HF...06%26rk%3D3%26

 

What would you do if a customer brought a vehicle back to you after he had already paid you to fix it?

Would you expect him to spend money and time diagnosing it himself?

 

while ill grant you that evap replacements arent common thats just not the case for the xj. i just did mine in my 98 and it solved the leak. lots of reading on these forums about failed evaps. combined with seeing dye mixed with my condensate water led me to the conclusion. it IS a common failure item on the xj.