A/C leak down test....help

[ma96782]

About 3 weeks ago I took my '94 Explorer down to the shop for A/c work......it wasn't working.

The shop did a diagnostic test.....and only had to re-fill the 134a.......1 lbs.

Now, three weeks later and I find the A/C isn't cold........looking under the hood, I found a leak at the fill port......it was wet and had bubbles.

At this point, I assume the mechanic, just topped off the system and sent me on my way......so much for paying for a diagnostic system check.

So, my question is:

Shouldn't the mechanic have tested the system.....for, leak down......prior to returning the vehicle?? How long should the mechanic have waited to see if the system was holding pressure??

Tomorrow, I plan on taking it back.......I expect to pay for the new valve and this time I want to make sure the mechanic tests for leak down prior to returning the vehicle. As for, IF I'll have to pay for more 134a.......well, I think the shop should foot that bill.....what do you think?? What would be reasonable??

Aloha, Mark

 

[1IronMike]

Mark, for sure take it back. What your mechanic should have done was totally evacuate your system, (recovered 1 pound), then hold it under vacuum for 30 minutes at a specific value, 29.9 inches vacuum being perfect. Then recharge with 2 pounds of new juice and some leak dye for good measure.

 

[BrooklynBay]

If your system already had freon, and held a partial charge, they could have used an electronic leak detector to test it. If they completely evacuated the system, this would be the time to replace the orifice tube.

 

[ma96782]

I went in today....shop says, "Yep, you got a leak."

They'll fix it.....though wrong parts were delivered today......so, I said I'll be back next week.

I'll pay for parts and labor (valve and installation).....they'll p/u the 134a costs to re-fill.

Thanks, guys........your knowledge was helpful, in speaking with the owner and getting this problem solved.

Aloha, Mark

 

[BrooklynBay]

What part was leaking?

 

[ma96782]

It was the valve (where you put the 134a in). I saw the bubbles and wetness.........sure enough it leaks. They said it appears that it is the only leak to the system and they're confident that the new part will fix it.

Aloha, Mark

PS.....I guess that plastic valve cover held some of the gas in "for awhile."

 

[BrooklynBay]

There is a way of tightening the pin, like on a fuel port, or on a tire with a special tool. That piece is spring loaded, and is screwed into place.

 

[ma96782]

Thanks.......though the new part will be waiting for me.........next week.........I forgot to ask about the, "orifice tube."

Aloha, Mark

 

[BrooklynBay]

You could buy an orifice tube in AutoZone for a few dollars. It is a stock item, not a special order.

 

[ma96782]

Is it easy to change? DIY? Or should the shop do it, only when the system is evacuated?

Aloha, Mark

 

[BrooklynBay]

You could do it yourself as long as there is no freon in your A/C system.

 

[ma96782]

It's done..........$18 for the valve change..........the shop paid for the 134a..........it's working now. Just hope I don't have any more problems with it.

And, I didn't do the orifice tube........as the shop only added more 134a to the system.

The good thing is, I get to take it back next week to test if it's still leaking. At least, I feel better about the one week trial period.

Aloha, Mark

 

[zhanx]

the vavle is just one of those things. In order to do the leak test you have to have your stuff hooked up. Hence why they didn't find the leak there. what should have been done after the leak test (minus uv dye in the system which allows for taking the gauges/hoses off) was a test off the vavles. Not hard but i notice lots of people jsut skip it.