Black Death

The more information you have the better conclusion you can come to.

 

The only information one needs in this case is:
- a/c off: belt and compressor / clutch pulley spins fine
- a/c on: belt and compressor / clutch pulley does not spin or turn.
Conclusion- compressor is seized.
The crank can continue to spin since its pulley is of a smaller diameter than the compressor and as such has less contact / surface area with the belt and is more likely to slip than the clutch / compressor pulley.

 

Yes but why did the compressor seize? You dont want to put a new one on and have it do the same thing.

 

Considering procedures when replacing the compressor includes flushing the system and filling it with the appropriate oil, whether or not mis-matched oil caused failure is a moot point since recharging the system will include the proper lubricant for the system, no?

 

More importantly, the system was designed with CFC-12 as the refrigerant. Will the orifice (a.k.a. expansion valve) operate well with HCFC-134a, or should it be changed for one more appropriate for the new refrigerant? And what about the high and low pressure switches: should they be changed?
And should the hoses be changed as well? ... other o-rings in the system?

 

Yes if the compressor died from a black death then you would do as you stated above, but if the compressor died from an exploding piston or the like you would do as you stated and also add an additional in line filter to catch any material that was not flushed out. That is why having more information is critical to finding out what happened , why it happen, and fixing the problem right the first time. So what caused the failure is not a moot point.

 

Most orifice tubes as well as expansion valves will work well with r134a but they can be switched out for ones that are meant for r134a.. High and low switches can sometimes be adjusted to compensate for the differences in pressures between the two refrigerants others can be changed. It depends on the type of hose used if it needs to be replaced or not, some of the older hoses cant hold r134a. All o-rings should be changed if the system is converted unless it already contains compatible o-rings. You do not need to replace all these parts to retrofit a car over, most can be done by only changing a few parts. Retrofitting usually goes by a case by case basis, what works for one car might not work for the other.

 

I just had my compressor go out on the highway which happened to blow the belt when the unit seized. Here's the kicker....I wasn't using AC at the time, the climate control switch was on DEFROST and the fan on the second click. The AC button was not depressed.

I know that the clutch on the unit is fine, another kicker....when i move the climate control switch to defrost and turn on the fan, the clutch to the compressor engages and the belt squeels something fierce from a locked pully, my guess from a jammed piston. Same thing happens with the AC is turned on. Is the defrost run off the compressor same as the AC?

I can live without AC, but the winter is going to require defrost. 854x4...you got any info about this? You seem to be a well of knowledge about this subject. Thanks!