1991 Mustang GT w/ R12 - need help

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fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

Westfalia wrote: Tue Sep 06, 2022 10:54 am Where in So.Cal are you located? I'm in N. OC and have a set of R-12 gauges I would loan out if you need them as AutoZone does. Just a thought.
I am in the San Fernando Valley - a little far away, though I appreciate the offer. I am hoping with the correct adapters I can use that 134/410 gauge set that I have borrowed.
fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

tbirdtbird wrote: Mon Sep 05, 2022 2:49 pm
The way to check for a leak at the compressor shaft seal is to put a shower cap or other plastic bag over the comp (after removing the drive belt), and letting it sit overnight. Then poke your sniffer inside the bag.

Also, you did not state that you sniffed the water drain from the evap under the car. Evaps are FAMOUS for leaks, so you have only done half the testing that needs to be done.

Also, as stated, I am pretty sure that "hot swap" core changer will not fit the 3/16 port.
Thanks for the bag trick - I will give that a try alongside sniffing out the EVAP.

Why wouldn’t the hot swap idea work? I’m looking for a Hail Mary here with that high side charge port.

I took a pic of the high side port was...didn't realize how dirty it was. It doesn't look much better underneath the compressor.
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tbirdtbird
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Re: 1991 Mustang GT w/ R12 - need help

Post by tbirdtbird »

Please re-read what I wrote

EDIT:
It has also been suggested that the core may just need to be snugged up a bit
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fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

Quick update:

I was able to start the car and engage the A/C today. It does not blow cold, but the clutch engages/disengages which is a good sign that everything works (for now) and is just low on freon. So, with the engine off I started poking around with the TIFF detector. Went over every line, connection, crimp, o-ring, condenser, accumulator ports, etc... and yes, even the evaporator drain by the firewall and got NOTHING. Only when I backed out the low side cap did it go off. I also tried applying soapy water but most likely there is not enough pressure in the system.

Only thing left is to remove the clutch and sniff for leaks from the front seal and try the bag trick as well.
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JohnHere
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Re: 1991 Mustang GT w/ R12 - need help

Post by JohnHere »

No need to remove the clutch. Place a plastic bag around the clutch and compressor case, secure it with a large rubber band, then probe inside the bag with your TIFF a couple hours later or the next day.
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fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

Thanks, I will give that a try.

Do you recommend turning on the car again or is that not necessary?
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JohnHere
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Re: 1991 Mustang GT w/ R12 - need help

Post by JohnHere »

Depending on how much refrigerant is still in the system, the compressor might or might not run after starting the engine. Nevertheless, running the engine for several minutes will warm-up whatever refrigerant remains, which will raise the system pressure somewhat and help with leak-checking.
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fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

Looking through my stash of R12, I found a can of leak detector. Any issue with using this stuff?
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tbirdtbird
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Re: 1991 Mustang GT w/ R12 - need help

Post by tbirdtbird »

Are you certain that is R12? I am not familiar with the name Cold Shot.
I am pretty sure that dye is the red colored dye tho, and I am not sure how well it shows up. They went to the yellow-green luminescent dye long ago.

But you have a TIFF sniffer! The sniffers trump the dye any day of the week!

Did you ever snug up the high side schrader valve core?
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fastsvo
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Re: 1991 Mustang GT w/ R12 - need help

Post by fastsvo »

I haven't had a chance to snug it up yet.

Unfortunately, the TIF took a sh%t. The wiring harness got tangled up and in my haste, I accidentally pulled one of the leads out that go to the wand. I opened it up and couldn't confirm where the yellow lead gets soldered onto. So either I'll find another one or visit Harbor Freight.
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