Anybody know how hard it is to convert my a/c in my 79' f150? Its currently not working and it's starting to get really bad hot down here in Texas and I'd like to have just a little bit of cool air haha! Do those conversation kits from the parts stores work good or would I be better off changing the whole system?

 

For starters you need to make sure you have no leaks in the system.

Then you need to either rent a machine, or take it to a shop to purge all the r-12 out of the lines.

Then you can add the newer refrigerant, but I'm not sure if the old compressors are to keen on running the newer oils in them.

I may have missed a step but that's at least the gist of it.

 

Good info! Would ALSO like to know. Kinda figured some things had to be replaced to run the r134.

Subscribed!

 

How do I check for leaks in the system?
And where can I rent a machine to purge the system or would that be something that I'd be better off letting an a/c shop do that?
Would a new compressor from LMC work or would I have to get one that goes on say an OBS truck? Or even a different compressor then that?

 

3 different types of Ford A/C were available for 1973/79 F100/350's & 1978/79 Bronco's. The parts do not interchange!

1) Factory installed integral A/C is combined with the heater. The A/C controls are located in the same panel as the heater controls.

2) Deluxe dealer installed A/C is combined with the heater.

The two A/C switches are located in the HUGE dash bezel that sweeps across the entire right side of the dash, covering up the glove box.

There is a separate "hang-on" glove box bolted to the bottom of the dash.

3) Economy dealer installed A/C is not combined with the heater. The two A/C switches are located in a panel that also contains two A/C registers.

This panel fits into the dash to the left of the glove box.

 

Its factory air I believe because the controls are on the same panel as the heat and the glove box is in the dash like it is from the factory

 

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Easiest way to check for leaks is to pressurize the system with nitrogen and monitor it for decreasing pressure. If you find it is leaking, check all joints with soapy water (can generally mix soap and water in a spray bottle, spray the joints' area, look for bubbles.) IF you are not leaking you can try purging the system by pumping a lot of alcohol through it, blowing it as dry as possible, then filling it with R134. You will need to change compressor oil if you have a rotary compressor. In a York I believe the oil is separate and I am not sure whether a change would be needed.

You will for sure need to change the dryer. You should change the condenser to a 134a condenser, but some people have just changed the dryer and run with new refrigerant. If you have a thermal expansion valve (TXV) you will need a new one made for R134. R134 typically does not cool as well in a R12 system as the R12 did, but it is much cheaper and you do not need a special license to buy it. If your compressor is shot, converting it to a Sanden-style rotary compressor is not a bad move - the drag on the engine is perceptibly less. If you swap compressors, pick up a R134a-compatible compressor, condenser, and dryer (total if you buy an adapter bracket to mount the compressor should be less than $400). Be prepared to buy a hose or two...all would be better but may not be needed. If you have a buddy who knows A/C, start buying him beer. And tint your windows.

 

Houstondave nailed it. I forgot about the driers and condensors. As far as a shop doing it vs doing it your self, that's up to you and the amount of effort you wanna put in vs money saved.

 

Just did mine a few months back, the process is fresh in my mind. Love the Sanden compressor - the 300 doesn't even notice when I turn the air on. Not the most efficient air in the world, but at least it works well enough to keep it cooler in the cab

 

I'm in the middle of refreshing my '78 air (live in Texas too!). Converted to Sanden compressor, new dryer, condenser and expansion valve. About to take it to get it flushed and charged.

Check this thread out if you're interested in going that route: https://www.ford-trucks.com/forums/1...to-sanden.html

 

If youre going to 134 it its best to replace the condenser too. A 134 condenser has more cooling area and works much better than the OE one designed for R12. I did a kit from Classic Auto Air which included everything except the evaporator for around $800. Works great so far.

 

Whereabouts in Texas are you at?
I do a fair amount of a/c work and wouldn't mind helping a fellow dent owner out if you aren't too far away.

 

What all does that kit include?

 

About 90 miles north east of Lubbock. A little town of 200. It'd be awesome to have some help on this project! Lol