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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
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Massachusetts
So i signed up for an automotive AC forum, and holy hell did i learn a lot.

Not even sure how to summarize with that i've learned. Lets try a few key bullets

  1. The original Mustang condenser is a Tube-and-Fin style. Modern condensers (starting in 1994 on the Mustang) are a Parallel flow type which is MUCH more efficient. ALL of the aftermarket replacements on the market are the parallel flow variety.
    1. Parallel flow (PF) condensers have less internal volume than Tube-and-fin (T&F) condensers
    2. As a result of this internal volumn being less, you much reduce the amount of oil/refrigerant used.
  2. In the early days of R134a retrofits, Ester oil was added to the original mineral oil to work with the r134a. This added to the volume of oil, so it was recommended to reduce the amount of R134a to avoid excess pressure due to 1) excess oil and 2) using a T&F condenser with 134a (very inefficient)
  3. If doing a retrofit, it is HIGHLY recommended to ditch the T&F condenser and install a new PF condenser before converting to the 134a. You will have poor cooling with 134a and our original T&F condenser
  4. Since many people will install a PF condenser, they must reduce charge/oil capacity to account for the reduced internal volumn. How much is an unknown right now.
    1. Mixing mineral oil with Ester oil will result in more oil capacity which requires dropping refrigerant charge to avoid over-pressurizing.


According to this chart, Ford changed the oil charge level in 1989. Not sure why
1625679882903.png


The drop in charge level is due to the volume. In 1994, the evaporator was close in size to what was on the 86-93 Mustangs. The big change was the condenser. The oil and refrigerant levels were lowered as a result.

I'm going with R12 and mineral oil here. My system is all Ford parts except the condenser is a new PF style condenser, which is smaller. Instead of the 40 oz/10oz R12/oil charge recommended above, my intention is to start with 34 ounce of R12 and 8 ounce of oil.


The big takeaway with what i've learned is the condenser differences. If you are R134a swapping an original Mustang setup, you really should ditch the T&F condenser and replace it with a modern PF replacement unit. (Spectra-Premium 7-4453 condenser)
 
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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
Interesting. Do you think the efficiency will change using the PF style and R12? Can you share what AC forum you signed up for?

Yes, efficiency goes up. I don't know how that will translate to real world experience in our cars. Perhaps the system will cool better at idle with less airflow? But the take-away was that the change in design was necessitated by the change to 134a. In the 2000's Ford changed to a 6mm Piccola type condenser which was even better. Not sure there is a aftermarket version of that for the fox cars though.

I've been browsing here. I made a post, you'll likely see it

 

TIGGER

Founding Member
Mar 6, 2000
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Thanks I am still running R12 in my Saleen with the original fin style condenser in the front. It is looking pretty ragged and thought I would replace it at some point in the future but I plan on staying R12 on this car. Was just curious if going to the newer style on R12 would be a negative.

I’ll check out that web site later tonight. Thank you
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
I plan on sticking with R12. Nothing i read suggested it would be a negative.

I look forward to making ice cubes on a 95 degree day. Driving a black car with a black interior with a sunroof is absolutely brutal. Our summers here in MA are short enough and I hated having to plan my drives around the weather so i wouldn't sweat my butt off in misery. I'm a windows down, AC on kinda guy
 
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90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
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I've retrofitted more mustangs and old ford's than I can count. The way I do it is to drain the old compressor in a measuring cup and add the same amount of Esther oil. Also, flush the lines, evaporator, and condenser out, replace the orifice tube line, and install a r134 pressure sensor. The AC in my car would get so cold it would mist out the vents on a 95 degree day. Vent temp usually between 35 and 42 degrees...depending on outside ambient temp and humidity. Never noticed an issue with the condenser but I'll take note of this for future references.

My compressor is original to my 89 convertible. It still works great but I may follow your steps to rebuild it before it's too late.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
Finally finished cleaning up the housing and got around to painting it. Used Eastwood’s Alumablast paint, which I’ve used on all my other aluminum brackets and such. It looks a little bit more blingy in this pic than in person

9CDAE2C6-0DDA-40B7-B090-73DCABCC26A9.jpeg


I’ll give this a few days to dry and then reassemble it
 
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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
Compressor done. Check the tech thread for more details.

need to put the clutch back on, leak check it and fill it with oil.
769CB866-A437-4BE0-9196-0C6F2B17D194.jpeg
 
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v8stang289

Advanced Member
Apr 22, 2008
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I've spent the last couple days reading through this thread in my spare time. Awesome job so far. I wish I had the patience and attention to detail that you have. It's also been very informative as I have a compressor that worked great but needs resealing.
I cant wait to see more progress.
 
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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
Ok compressor is done.

New SS hardware and arp mounting bolts. The mounting bolts are M10 x 1.5x 25mm
01D6F07F-8D56-4839-9097-877CADDE37D0.jpeg
95AC14C1-8F02-46A5-9691-9E890A1C29A6.jpeg


new NOS coil
3C293261-D4C7-4FD0-BDB4-BE1F86BCF5B9.jpeg

New NOS pulley
859E4F2F-1DB1-4B73-957F-D2E426BFE2D1.jpeg


new NOS outer disk
6DEA13D8-9362-4DB2-98A5-B9BEE2B06FDB.jpeg


just need to check the shim and install the retaining nut.

leak test and install!
 
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Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
36,174
12,090
224
Massachusetts
Clutch gap set. Disk torqued down. Filled with 5 ounces of fluid.

I tried to leak test it, but it wasn’t happening. I mounted it on the car and will leak test the entire system at once. I actually haven’t seen my engine in a few months. I had it covered up with a plastic sheet to keep it clean

next up, clean up the distributor

1042BCC9-79B2-43BA-86CA-5CF18B2312A1.jpeg
8ADACE42-3324-4D61-91B7-80E37964BAA5.jpeg
 
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