AC Rebuild - Part 3 - 08/31/2018

Ah yes, the moment of truth has arrived! Time to see if the vacuum held and if so, charge and verify the system is working!



Vacuum held overnight at 27inHg or so. This is a good sign. If it was going to leak, it would have done so by now.



Gotta get my cans of R134a ready to go.



Hooked in to the gauge manifold. The car was off and I turned 3 cans upside down to let gravity and vacuum pull the contents in as quickly as possible to avoid freezing.



Two cans yielded final pressure of 65psi. Liquid freon sits at 78psi, so this is close to fully charged.



OMG the compressor came on! It sucked down the freon to 15 psi where the low limit switch kicked in. The low limit switch wouldn't be cleared until the pressure in the drier reached 25psi or so (I like verifying that my interlocks work). I added a can while it was in this process and it continued to run and stabilized at 30psi. Then it was time to hook up the last can.



The drier instantly turned cold and condensed a ton of water all over it. This is also a good sign...



Last can is warmed up with warm water to stop the freezing that it is doing.



After getting 4 cans of 12oz freon installed (originally a 56oz system, 85% is 48oz, it probably actually took 45-46, which is closer to 80% with 8oz of PAG 150 synthetic oil) it equalizes to 35psi on the low side and roughly 185psi on the high side. Can't really complain there! It's textbook R134a numbers.



The temp out the vents is roughly 48F. Not perfect, but the belt is slipping on the compressor, the fan clutch isn't in great shape, and the blow motor is kind of having issues with noise and whining, so there's simple things to work on. The condenser has a ton of heat on it, indicating that it's working correctly and if I want colder temperatures the air flow should be improved.



The sweat on the pipes is insane. It's getting stinking cold, down around 35F according to the temp gauge. That's good. Tells me that the system is functioning correctly and that's what matters. If it wasn't getting cold or the compressor was cycling on and off I'd have pressure problems or freon flow problems, which isn't the case here. It's in good shape it appears. Road test time!

Tighten compressor belt, check\replace fan clutch, and blower motor. And drive it around a few times to see how it behaves. If it gets colder when I'm cruising on the freeway or highway, it's obviously an airflow issue that needs to be corrected. If not, well it's better to have 48F air than 85-95F air out of the vents, so I'll just deal with it!

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Last updated August 31st, 2018