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Compressor rapid cycling

Jim1941 on Wed March 14, 2012 11:43 AM User is offline

Year: 2002
Make: Mercury
Model: Grand Maquas
Engine Size: 4.6
Refrigerant Type: 134
Ambient Temp: 75
Pressure Low: 30-40
Pressure High: 60-75
Country of Origin: United States

Last Aug I had a failed compressor and replaced with rebuilt compressor from Amazon, replaced the Accumulator, condenser, and the orifice tube . I flushed the system with a flush sold from Amazon called Kwik klean. Add oil and vacuumed down for 1 hour, charged system. Worked great for 6 mo. 38-40 vent temps

Monday the compressor began quick cycling. Hooked up gages and found low side around 30-40 and hi 75. Jumper d low pressure switch to see if it would help thinking I had a bad switch. No improvement and some noise from compressor. Thinking I may be low on gas added a half of can of 134. Again jumped switch to add gas. Compressor made more noise and began to lock up.
Had the system evacuated (did not measure amount). Removed everything except the compressor. Found no sign of leaks (put in 1/4oz dye when rebuilt) The orifice tube was coated with a slimy substance, no metal was found the short end was black. Tested the slimy substance and found it was water soluble. After cleaning I could blow through it.
I have ordered a new motor craft compressor and a 4 seasons accumulator and will buy a new orifice tube and flush with the same produce.
The oil that was in the accumulator is clean and I used a que tip to see if there was any metal or contaminate and found nothing even in the compressor tubes.
Do any of you guys have any advice as to why this happened?
The fact that the slimy water soluble makes me think that it could freeze and block the flow, however after sitting for a while it make no difference and continued to short cycle.
I think my compressor failed but why the short cycle.
Thanks for any help and advice

mk378 on Wed March 14, 2012 5:52 PM User is offline

The refrigerant leaked out, causing low pressures and short cycling. Then you put a lot of stress on the compressor jumping the switch on an empty system.

PAG oil is water souble. It's also likely you have flush residue in there.

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