Got the new R134A compressor, drier, oriface tube and hoses on, flushed the condensor and evaporator, pulled a vacuum on it last night and it held all night. I charged it up today and the system cycles off and on every two to three seconds, so I jumpered the low pressure switch just so the compressor can run and the system could circulate.
It blows somewhat cooler air and the high and low readings were around +25 on both gauges.
My main concern is the compressor and hose going to the condensor are hot to the touch...Is that normal?
I did add approximately 8 oz of the PAG oil to the system.
Any thoughts would be appreciated

 

Did you charge it with two cans of 134a?

 

Added another can as car was running, at normal temp, a/c on high.
I noticed as I was filling with the second can, the clutch stayed engaged much longer. I did not know it took a while for a can to empty, I thought it would be faster.
Air is blowing cold and the line going into the evaporator and the accumulator feel about the same temp.
I am no A/C tech, but a good learning experience

 

It needs more gas if it was 70 or better at the Condenser, because at that temp, it shouldn't drop low enough to open the Low Pressure Contacts.

You did include 8 oz's of oil?

Was the orifice swapped out or cleaned? I know this guy who was so excited about his 1st compressor rebuild, that he slapped it on and crammed 2.25 lbs of fresh R12 into it only to watch it cycle like there was a half a pound in it. The orifice was full of crap - he should have known it, but was too anxious to check out his rebuild.

Of course the high side is hot - It's designed to average 200 psi. R134 at 200 psi is 131 degrees; about 20 degrees less with subcooling. Put a digital thermometer on the line to see what the subcooling is after you get the high side - if you're curious.

What are the operating pressures - 1200 t0 1500 rpms held steady, system on high, fan cranking? What is the air temp at the Condenser?

For cooler days, you'll want the Low Pressure Threshold a tad lower. If you didn't buy an R134 switch, adjust the old one (if needed), by disconnecting the Blower Motor and noting the cutoff threshold on your Gage. It should be 22.5 psi (for R12 it's 25 psi). There's a screw between the switch terminals (most switches) which you can turn counterclockwise to lower the threshold; clockwise to raise it. Try a half turn at a time and retest until you get 22.5 psi.

 

Thanks SunCr,
I did add 8 oz. of PAG oil to the system, distributed throughout the system and the oriface was replaced with a new one.
I still need to put my gauges on it and check and will repost, and a thermometer on the vents, just ran out of time.

 

O.K. when the car is at idle (around 700 RPM) the clutch stays engaged, so I put the gauges on, pulled the blower switch plug to trip the low pressure, set RPM to 1500, and the clutch disengages at 22- 23 PSI and kicks back on around 45-48 PSI on the low pressure gauge. The rpm was set at 1500 rpm and the fans kicked on when the PSI increased to 45...I guess to pull in cool air across the condensor. As the fans ran, the low pressure started dropping.
High pressure was around approximately 200-225 PSI, but I was paying more attention to low pressure side.
I need a thermometer to get the vent temp still.
There is no frost build up on anything but there is water condensation on the evap tube and accumulator.
I am still learning, this is all new to me.

 

Sounds normal to me; assuming it's 70 - 90 degrees at the Condenser. Fan is maintaining Condenser at about 200 psi (or a tad above 100 degrees) and that meters liquid into the Evaporator at around freezing or 28 psi though superheat makes the real temp 40 degrees. You should see high 40's at the Center Vent. If you want to get a steady reading, keep the radiator fan running by disconnecting the fan switch.

 

Thanks SunCr, couldn't of done it without your help.