A/C leak

[visitor]

Our A/C system has developed a leak. A day or two after recharging the system, when the compressor clicks on, it is immediately followed by a hissing sound near the rear evaporator.

There is no orifice tube in a line near the rear evaporator, is there?
Any "hissing" sound in the vicinty of the rear evaporator suggests there's is a leak there, no?

Thanks

[splatt222]

YOU NEED TO TURN VEHICLE ON, TURN AC ON FULL MAX PUT A CAN OF AC RECHARGE WITH AC DYE LEAK TEST INTO THE LOW SIDE PORT . WHEN IT HISSIS , PUT ANY BLACKLIGHT AROUND THAT PARTICULAR AREA . LOOK FOR A LEAK .USUALLY ,IT WILL BE A YELLOWISH, GLOWING COLOR . BY THE SYMPTOMS ,IT SOUNDS LIKE A SLOW LEAK . UNFORTUNATLY ,THERE ARE NO "PATCH" FIXES OUT THERE THAT I CAN STAND BEHIND . HOWEVER THERE IS A PRODUCT I'VE TRIED (AN ADDITIVE ) THAT WORKS . BUT WE ARE GETTING AHEAD OF OURSELVES . I PERSONALLY CANNOT REMEMBER WHERE THE TXV IS ON THE REAR AC OF THIS VEHICLE IS . HOUEVER I DO KNOW RULE OF THUMB ON ANY GM VEHICLE WITH REAR AC IT IS USUALLY LOCATED 4"- 6" BEFORE THE EVAPORATOR CORE QUICH DISCONNECT CONNECTOR , IN THE HIGH SIDE LINE BETWEEN THE HIGH SIDE LINE AND THE EVAPORATOR CORE. I HAVE NEVER HERD OF ONE HISSING BUT,,, I DON'T KNOW EVERYTHING !!! LET ME KNOW , PAT.

[throrope]

Years ago we had a leak at a rusted connection in the lines to the rear evaporator.

[visitor]

that whole rear evaporator assembly is encased in a plastic housing that makes looking at the individual lines/components/connections kind of difficult

i'm thinking the best first step might be to disconnect the lines that go to the rear system to see if the system works & holds charge isolating only the front A/C - seems like a relatively simple initial appraoch, if i can find good way to adequately seal the ends of the front lines...

[Leeann_93]

YOU NEED TO TURN VEHICLE ON

I won' t quote forum rules, but please, please turn off caps lock. It's hard to read, plus it's considered shouting and rude online.

Thank you.

[Pie R Squared]

For the last 5 to 6 months I have been noticing a leak under the engine near the passenger side that I thought was brake or power steering fluid but now believe it to be PAG oil because the AC is very weak. Might anyone have any ideas where to look for the leak if I am getting a PAG oil drip under the engine closer to the passenger side? I have rear air, 83000 miles.

FYI: The GM Parts Giant web site www.gmpartsgiant.com has an excellent AC diagram and components list of the AC system for trouble shooting and AC Delco www.acdelcotechconnect.com has a good web site for replacement parts with GM and Delco part numbers that you can use to seach the web for parts.

[AstroWill]

Dye is about the best way to find the leak, highly recommend it.

[visitor]

Found a corroded pipe where it crosses over (& touches) the steel coolant lines going to the rear heater core. Think I'll try wrapping epoxy/fiberglass patch aroung the aluminum pipe where the leak is for a simple, cheap fix...

[chevymaher]

Found a corroded pipe where it crosses over (& touches) the steel coolant lines going to the rear heater core. Think I'll try wrapping epoxy/fiberglass patch aroung the aluminum pipe where the leak is for a simple, cheap fix...

Cut it with a tubing cutter and splice with a compression fitting.

[visitor]

compression fitting's a great idea, but the breach is at a bend in the line
the 2 really rusted lines are the coolant lines to the rear heater core, one of which couldn't more graphically demonstrate how it "ate" into the A/C line
...so, tonight, i'm bypassing the rear heater hoses up front to avoid an inevitable coolant leak in those rusted lines.
tomorrow i'll head out to the local bone yard & find an end section of that A/C line to cut out far enough forward to have a straight section to use a compression fitting on...

[AstroWill]

At first I seen you write about an epoxy/fiberglass patch, now it seems like you have the perfect plan.

[throrope]

Before running off to the bone yard, do an internet search, and not only at parts houses. I bought an exact fit oil line from amazon.com for 5 bucks free shipping. Apparently a retailer had a stock of one and was looking to eliminate slow moving stock.

Also, don't take any short cuts on the AC lines. The pressure is more than any other line on the truck, refrigerant cost more than gas and problems are not very forgiving.

[throrope]

At first I seen you write about an epoxy/fiberglass patch, now it seems like you have the perfect plan.

epoxy will never hold.

[AstroWill]

At first I seen you write about an epoxy/fiberglass patch, now it seems like you have the perfect plan.

epoxy will never hold.

Exactly, but now he has changed to a compression fitting, which will work perfectly.

[throrope]

At first I seen you write about an epoxy/fiberglass patch, now it seems like you have the perfect plan.

epoxy will never hold.

Exactly, but now he has changed to a compression fitting, which will work perfectly.

[visitor]

compression fitting went on well
time will tell...