1993 Ford Bronco XLT 5.8L Air Conditioning Rebuild

[Whipsaw]

Hi everyone! I hope all are enjoying the holiday season and filling your Christmas list with lots of new Bronco parts! Its winter, the perfect time to tackle the Air Conditioning. The A/C in this vehicle is an original R12 system, working, will cool on a cool day. As I will have to convert from R12 to R134a, I've decided to replace the whole kit and caboodle (probably even the heater core). Already had the system pumped out, currently researching parts - any recommendations on a compressor? I have an FX-15 in place, the FS-10 replaces it for R134a, I'm leaning toward the Motorcraft unit on RockAuto, though I'm tempted by the FourSeasons at less than half the cost. RA has all the parts, as well as a R134a rated condenser, which will provide greater heat transfer and greater cooling capacity. Replacing everything will eliminate any old oils and residues. Once install is complete, I'll have my mechanic pump it out and charge it. That's the plan.

 

[miesk5]

Yo Whipsaw,
Sounds good!
Here is one issue, however you and the mechanic MAY need to address;
Odors, Eliminate Air Conditioning Musty & Mildew Type TSB 98-2-7 for 92-98
Source: by Ford via v8sho.com

Here's your 93 A/C/Heater, Vacuum Diagram for future use such as a damaged hose due to age;

 

[L\Bronco]

Hey Whipsaw,
sounds like an awesome plan.
When you assemble everything, make sure to use mineral oil (the stuff for the R-12 system) on all of the O-rings and seals. PAG and ESTER (R-134 oils) are hygroscopic and absorb moisture. It can cause corrosion and moisture contamination in your system. 4 seasons makes a decent compressor as well, I have never seen any evidence that the Motorcraft ones last longer. P.S. if your new compressor doesn't come with compressor oil, put 3oz of mineral oil in it. R-134a wont carry mineral oil around so it extends the life of the compressor. Still add the correct amount of PAG oil as well.
The only contamination in a retrofit that is an issue is if R-12 refrigerant comes in contact with PAG oil. It creates acid and causes black death in a retrofit job.
The way you are doing it, you have nothing to worry about.
Hope that helps,
Cheers

 

[Whipsaw]

Appreciate the links, diagrams and advice! I'm slowly ordering in the parts as I don't have a place to work. New driveway going in and it needs a month to cure before I can drive on it. I don't want to do any work in the street. On top of that, the Brake Master Cylinder just gave up the ghost - all at once - pedal goes to the floor, pumping gets you nothing, first I've seen that (historically, I've gotten a week or two of pumping the brakes before replacing a MC). The emergency brake is getting some use. I have the AC Delco MC replacement in hand, going to paint that with grey VHT engine paint; planning to replace the booster with a Cordone reman as well. [Should I start another thread for the brakes, or just nest it in this one?? Its nothing remarkable, maybe skip doing a thread on it.]

 

[Whipsaw]

Some of the research in this job included getting the markings off the existing compressor:
58
790
2M7 PHASE 17 : 41
FX-15 MODEL F2TH AA

'The FX15 was known for not surviving the higher pressures of R134a which contributed to the dreaded "Black Death" failure well known for this units.
The FS10 was a slightly better design and is a direct replacement for the FX15. Be sure to use only a new Motorcraft compressor, with the correct size/ridge pulley/clutch with the clutch connector at the correct clock position.' (forgot to grab the source link)

Somebody got the closeout Four Seasons pump, going with the Motorcraft YCC193 (cross references with 5U2Z19V703FA - F150); I believe the original 93 Bronco R-12 compressor is MOTORCRAFT YC2523.

I'm going with the AGILITY 7013605 Condenser as it is rated for R-134a and should transfer out the heat of compression at the appropriate rate. Replacing the evaporator with GPD 4711375, although it doesn't specify, the cross flow construction should be good for R-134a also - and it has a corrosion resistant coating.

 

[Whipsaw]

Regarding the Brake Master Cylinder, couldn't get any grey VHT High Temp paint, so I used up the metallic orange I had on hand. My '01 Explorer 5.0 blew a head gasket the other day (I'm blaming it on the cold), so I sent the Bronco to my mechanic to install the MC, a new Brake Booster, and to flush out the old brake fluid (which he should do anyway) so I'm back to two vehicles on the road in short order. Working on a game plan to fix the Explorer. Still ordering in A/C parts, new Evaporator arrived with the brake booster.

 

[miesk5]

Yo Whipsaw,
Well Done!