Air conditioning fail.... HELP

[72ray]

I’m not having a good run with C3 (1972) air conditioning repairs.
I had the compressor (original type) replaced and repaired an a/c hose that had burnt through thanks to its proximity to the right side exhaust manifold.
The compressor blew 6 months later and the a/c guy wouldn’t have anything to do with it when I asked WTF!
I’m not very knowledgeable about the a/c system and I’m concerned that there may be debris in the system that may have caused a blockage and or the new compressor to fail. HELP!
TIA

 

[Tourmax]

Well, until the system has had some troubleshooting done, you son’t really know why the compressor failed.

Compressor failure is usually lubrication related.

off the top of my head: not enough oil in the charge or, and this one is not a good one, when the compressor was replaced they used pag oil in a system that still had mineral oil in it.

R12 uses mineral oil and r134 uses PAG oil. The two are not compatible and generally just turn into a goopy mess and don’t lubricate well.

so if they charged it with 134a, they should have replaced the compressor, replaced the dryer and flushed the system clean. Then you can change the fill to 134a and pag oil.

it doesn’t really matter if its got pag or mineral oil in it, they both lubricate adequately. But you can’t put mineral oil in 134a or vice versa and you can’t mix them or bad things will happen, like a seized compressor.

they also should have at least changed the orifice, which has a filter screen on it that clogs up over time. An ac system is a sealed system, but it eventually contaminates itself with filings and seals breaking down. That screen is meant to capture it, but it does need to be replaced occationally. Usually, thats when major service is done to the ac system. It only costs a coupke bucks, but it makes a big diff in how the system performs.

Other things can seize a compressor, like contamination or water in the system. It doesn’t take much and you need to pull a vacuum on the system and leave it running for a couple hours so any water boils off and the system is totally void of atmosphere.

Hopefully, you have a receipt that should itemize what they did, which should help point you in the right direction.