Automotive Air Conditioning Information Forum

It annoys me that regular hard-working civilians get taken by less than qualified AC repair companies, whether residential or mobile.
To the vast majority of car owners, AC is a black box, and they need to be able to trust who they bring the car to. Too bad it didn't work that way here.

I find myself wondering if the 'technician' was an actual repair shop or a shade tree friend.
We don't always get all the info right away.....

ROBIN wrote: ↑Wed Sep 08, 2021 5:12 pm The car is original. Has not been converted in any way.

So the technician charged this vehicle with R12 refrigerant?

bohica2xo wrote: ↑Wed Sep 08, 2021 10:36 pm

ROBIN wrote: ↑Wed Sep 08, 2021 5:12 pm The car is original. Has not been converted in any way.

So the technician charged this vehicle with R12 refrigerant?

Great question.

I see at least 2 scenarios which could have caused issues:
1. New compressor might've arrived filled with 525 mineral oil and R134a was added to an R-12 system by "tech".
2. New compressor might've arrived filled with PAG oil even if R-12 added by "tech".

This is a licensed shop and was highly recommended. Reading your comments I lean towards a faulty installation procedure due to lack of knowledge of classic cars or lack of proper supervision at that shop. Thanks for your comments. They have been very helpful so far.

The car started out R12.
You are saying it was never 'converted' meaning converted to R134, the replacement refrigerant for R12.
The two refrigerants use very different oils.
There is a very good chance the new compressor came with R134 oil which is so called PAG oil.
If it was then charged with R12, this incompatibility would damage the compressor for sure.
The correct oil for R12 is mineral oil.
There are many missing details without which we may not be able to make very many more suggestions.
Also, if the old compressor crapped out on the inside, it would have sent shards of metal and trash into the system, necessitating a flush of the evaporator, flush of the condenser (only if the old tube and fin type, replacement if the parallel flow type), replace filter/dryer, and replace TXV valve.
Is there a breakdown on the paperwork they gave you for exactly what work was done I wonder.
If the old compressor burned up, and they did not do what I just listed, and only changed out the compressor, then the new compressor won't last long at all, the trash now inside the system will eat the new compressor alive.

AC is more complicated than ppl think. Even more complicated than a lot of shops think.

The system was flushed to remove any shards and a new condenser was installed as well for the same reason. Concerning the oil/refrigerant, what type (specs) of oil or refrigerant is required r for this R4 Style; w/ 9 O'Clock Coil; Piston Compressor? The problem was probably related to those.

It depends on which refrigerant type you plan to use.

R12 needs 525 Mineral oil

134a needs PAG150 in that compressor

Either way a dry system needs 8 fluid ounces of oil, and 56 ounces by weight of refrigerant.

Any replacement compressor should be filled with 6 ounces of the correct oil on the bench, then rotated and drained. This flushes out any unknown oil. Then at least 2 ounces of the 8 ounce oil charge should be added to the compressor inlet port while rotating the compressor shaft before installation.

A system that large should be liquid charged through the high side port. Trying to vapor charge that system through the low side port will smoke a compressor.

Do NOT jumper any switches when charging. Jumper wires kill compressors.

I think I got it. If the car is not converted to R134a, which is the case, the shop MUST use R-12 Refrigerant and the compressor MUST be flushed with 525R-12 Oil and then filled with that oil.

ROBIN wrote: ↑Thu Sep 09, 2021 12:56 pm The system was flushed to remove any shards and a new condenser was installed as well for the same reason. Concerning the oil/refrigerant, what type (specs) of oil or refrigerant is required r for this R4 Style; w/ 9 O'Clock Coil; Piston Compressor? The problem was probably related to those.

What puzzles me is why say you were ripped off. All this was done. You purchased products and had them install them. They failed; where is the blame for what they have done? You may have just received a bad compressor. Do you expect them to remove and replace your Rock Auto Parts for free?

I just not seeing where the shop being professional or not, with what was listed here did a whole lot wrong. The only thing I see is trusting the amount of oil in the shipped compressor. We never suggest that to customers.