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AC work, diagnosis made kind of easy

BoondocK5

BoondocK5

Chevrolet Bone Collector
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Some back story:
Wifey's 2003 Ford escape(she likes won't trade)
Blew its compressor all over the ground. Broke the belt, hot air, the whole deal.
Me, being kind of Zeus related when come to all things wrench turning related.
Figured I could fix this as it's just parts, and not rocket science, (I can do some rocket science shit) just high school science level physics.
New compressor, new belt, new reciever/dryer, new condenser, new orifice tube.
Pulled all the ac lines off blew them all out with "NON chlorinated brake cleaner and compressed air till no more gray goo came out, only clean brake cleaner.
Then did the same to the evaporator. Did not replace this as it's a rather lengthy, tenuous job.
Just blew it out with brake cleaner and compressed air till only clean brake clean came out. It alone took 2 cans.
Reassembled it all, using a bit of PB blaster to lube all the seals to ease with reassembly.
The oriface tube didn't like its new home and was very tough to get back in its hole. Some thing snapped inside while pushing it into the tube.
It looked OK, so, back together we went.
On evac and recharge, it made cool air, not cold, and the pressures wouldn't go anywhere but 130 psi on high and low sides. Not good at all.
But, still made pressure, so,compressor was still OK. Just no pressure differential.
The thing that makes the differential is the orifice tube(or expansion valve, if that's what you got.) So,fast forward to today. Put in new orifice tube, recharged system with R134 and 6oz of PAG oil and walla, pre orifice tube side hot, post orifice tube side ice cold. Pressures are 52psi low side. 230 high side, (its a warm day here) AND, very cold air blowing in the cabin!

WIN!

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eodcoduto said:
A/C is black magic, like an automatic transmission.
Click to expand...
Neither are that bad. AC you can learn on your own. It's high-school level science, put into automotive stuff.
Automatic transmissions are something you should go to school for. It's Hydraulic theory in action. If you can wrap the ol' bean around Hydraulic theory, you can understand automatic transmissions.
 
And you should spend the $100 on the gauge set $69 and shop air powered vacuum pump $29 from the Harbor Frieght.
I don't do a ton of AC work, so, I can use the cheaper equipment(read not the $2000 set from the SNAP ON rape truck) Harbor freight stuff worked well enough to let me pull 25 inches of vacuum, the gauges let me see that the vacuum held for well over 2 hours.(ac system was sealed)
And, gauges showed if system was functioning correctly.

Screenshot_20240604_072518_Chrome.jpg
 
I used the HF r134a gauges, my, Old R12 set from snap on leak, and no longer supported by them.
Have a nice Robin Air vacuum pump though.
Glad the wife has nice ac now good job.
Only thing I would have done different would be to lube orings with pag or Ester oil.
 
AC work sucks just enough, to not want to do it any more than required. Messed up seals are the worst. Impossible to locate without actually being at place that has them in bulk.
Plus, even the easy to get to one's require specialty tools to get the fitting apart.
Moral of the story? Do the job right, the first time. At the very least do things you know work and don't guess at AC related stuff. You will be wrong.
 
My hose tools are plastic color coded. I never used them, seriously, for better than 25 years. Now, I find myself using almost every weekend, keeping everyone's junk functioning. I can't be the only guy around here who knows AC stuff well enough to keep it functioning.
 
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Wifey just got back from a 35 mile round trip, in the heat.
She said it got so cold she had to turn down the fan, because it was freezing here out.
She is super sensitive to hot temperatures.
She said it just getting colder and colder. Which I said it would do as it started recirculating the cold air.
She is very impressed.
WIN!
 
BoondocK5 said:
The thing that makes the differential is the orifice tube(or expansion valve, if that's what you got.)
Click to expand...
The differential depends on the compressor and the restriction (orifice).

eodcoduto said:
A/C is black magic, like an automatic transmission.
Click to expand...
Learning A/C is much easier. You have 4 basic parts: hot coil, cold coil, compressor and restriction. (Yes, there are support components like electrical parts, fans and the receiver/dryer, but still...) The magic is in the refrigerant that absorbs and rejects so much heat during simple state changes. An automatic transmission is several hundred pieces.
 
Blue85 said:
The differential depends on the compressor and the restriction (orifice).


Learning A/C is much easier. You have 4 basic parts: hot coil, cold coil, compressor and restriction. (Yes, there are support components like electrical parts, fans and the receiver/dryer, but still...) The magic is in the refrigerant that absorbs and rejects so much heat during simple state changes. An automatic transmission is several hundred pieces.
Click to expand...
You gonna smoke everyone with the tech.
 
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