A/C leak test

[turboaddict2]

Going to go to my local mechanic to get the A/C system checked for a leak test and why it doesn't blow cold air. Curious what parts of the system will be checked for leaks. Thanks.

 

[Audiowizard]

I am not sure how old your A/C lines are but they are notorious for leaking at the flex hose connections to the aluminum piping. Instead of buying new ones, I went to my local AC Delco parts wharehouse and had new flex lines installed with the proper crimped connections for $35.00 (make sure they are clocked right so they will re-install like the originals).

To see if they are bad, grab the flexable house with your hand and twist them with moderate grip. If they twist at the connections then they are leaking, they are not supose to twist.

The AC Delco parts people told me that they can order me new ones but the NOS sets that they were getting had bad connections at the factory so the ended up repairing them at their facility anyways. I have had mine repaired and they have not leaked for 3.5 years

I repaired my own A/C system but I took it to a licensed guy who installed the R-12 after pressure testing it to make sure there was no leaks and I used the money off of the labor I saved to buy new parts for my A/C system.

 

[turboaddict2]

are you talking about thosetwo lines near the radiator support that go to the A/C compressor?

 

[Turbo Brian]

After evacuating and filling, the mechanic should use an electronic "sniffer" at all connections to determine if there are any leaks. Unfortunately, many of the cars leak at the compressor front seal only during cold weather and will hold a charge for an entire summer, only to dump the charge in the fall when the temps get near freezing.

 

[Nick Micale]

Originally posted by Turbo Brian
After evacuating and filling, the mechanic should use an electronic "sniffer" at all connections to determine if there are any leaks. Unfortunately, many of the cars leak at the compressor front seal only during cold weather and will hold a charge for an entire summer, only to dump the charge in the fall when the temps get near freezing.

They should check everything BEFORE filling with $200 worth of
R-12. This includes compressor, hoses, all fittings, condensor, switches, etc.

Some of these original systems are still unbroken and full, so if it is in good shape, the freon should never leak, hot or cold weather. My '87 T still has the factory fill and I think the GN as well.

 

[Turbo Brian]

If the system does not hold vacuum, a tech will not go further and fill the system. Repairs must be made first. When checking leaks, the amount of freon added to a system that holds vacuum is just enough for a leak check. I stand behind what I said about front compressor seals. They can be perfectly intact during a leak check, but leak out later during cold weather particularly on higher mileage units.

 

[turboaddict2]

Thanks guys. I'll keep those in mind. Hopefully the A/C system is not in bad shape.

 

[turboaddict2]

A/C system not in bad shape

I got my car back from the shop. the mechanic said it only needed a cycling pressure switch and a 1 lb. and a half of freon. I had a feeling all this time it was only low refrigerant and that the pressure switch wasn't turning the compressor.