Jehu
09-21-2016, 09:30 PM
So today I had a pound of r134a added to my system.
I hope with this thread I can understand better the possible reason.
last week I noticed the AC cooling power had lessened.
A few months ago I replaced the Evaporator/Expansion valve, Receiver/Dryer , High pressure side pipe and the Compressor.
Properly vacuumed the system before filling and it worked fine through the Summer.
When I noticed last week it wasn't cooling down as much I thought to check the Aux Cooling Fan.
It had seized. I can't say exactly how long I drove without the Aux Fan but the next day I replaced it.
I noticed however that though the fan spun when I tested it by jumpering the radiator temp sensor connector it wasn't coming on when turning on the AC.
I assumed the temp sensor was faulty but today I found it was due to the refrigerant being too low.
there was enough to engage the compressor but I gather there is a pressure sensor involved in switching the Aux Cooling Fan on.
So in hoping to understand whether I am likley to find I now have a leak or if I should be all set I ask.
When checking the syetem with twin gauges today I had the aux fan jumpered and the high side PSI was at 150 with the car idling .
When I pulled the jumper shutting off the Aux fan I saw the high side PSI jump to 175.
it fell back when I jumpered the fan again.
It occurred to me the increased heat on the condenser made the gas expand increasing the psi and if this happened when the other Aux fan failed since at that time the system was full to proper capacity could the increased heat have expanded the gas enough to force it to blow off via the compressor pressure release valve in which case that would account for the loss of refrigerant and I shouldn't need to be concerned I somehow now have a leak.
Obviously over the coming days I'll know if there is a leak . I just wanted to see if this idea is a sound explanation for the way it lost refrigerant.
I hope with this thread I can understand better the possible reason.
last week I noticed the AC cooling power had lessened.
A few months ago I replaced the Evaporator/Expansion valve, Receiver/Dryer , High pressure side pipe and the Compressor.
Properly vacuumed the system before filling and it worked fine through the Summer.
When I noticed last week it wasn't cooling down as much I thought to check the Aux Cooling Fan.
It had seized. I can't say exactly how long I drove without the Aux Fan but the next day I replaced it.
I noticed however that though the fan spun when I tested it by jumpering the radiator temp sensor connector it wasn't coming on when turning on the AC.
I assumed the temp sensor was faulty but today I found it was due to the refrigerant being too low.
there was enough to engage the compressor but I gather there is a pressure sensor involved in switching the Aux Cooling Fan on.
So in hoping to understand whether I am likley to find I now have a leak or if I should be all set I ask.
When checking the syetem with twin gauges today I had the aux fan jumpered and the high side PSI was at 150 with the car idling .
When I pulled the jumper shutting off the Aux fan I saw the high side PSI jump to 175.
it fell back when I jumpered the fan again.
It occurred to me the increased heat on the condenser made the gas expand increasing the psi and if this happened when the other Aux fan failed since at that time the system was full to proper capacity could the increased heat have expanded the gas enough to force it to blow off via the compressor pressure release valve in which case that would account for the loss of refrigerant and I shouldn't need to be concerned I somehow now have a leak.
Obviously over the coming days I'll know if there is a leak . I just wanted to see if this idea is a sound explanation for the way it lost refrigerant.