Revitalizing the stock A/C

[Tripdawg 10]

I recently purchased a 69 fastback A/C car with a 351w. I am not too familiar with working on A/C units and was wondering what advice would be given to get this thing serviced and up and working again (or at least attempt to). Everything appears to be factory stock and I assume it still has R12 in it. The blower motor also makes quite a bit of noise when on. Any help is appreciated.

[69gmachine 15]

If the entire system is intact, take the car to a local shop to see if it will hold vacuum. If you're lucky, you may just need to replace some seals and tighten up the fittings. If it leaks and you can't easily identify from where in the engine bay, you'll have to take the under dash unit out and send it out for repair to some place like Old Air Products or Classic Auto Air. I used Old Air Products in Fort Worth because at the time I lived in Dallas.

 

If the condenser has been exposed to the atmosphere for a while it will oxidize inside forming a fine white powder that will ruin the evaporator and possibly the expansion valve and compressor. If you know that's the case, I'd recommend replacing as much as you can at the same time.

 

ALthough it came from the factory with R12, if it's not working there's probably nothing in it now but air. There are replacements for R12 that cool better than R134A, but they're not as easy to find, so it's really up to you as to how much effort you want to put into getting it working.

 

There may be dirt or debris inside the blower making it louder than it should be, or the motor may squeak from years of not being turned. Replacing it is the best solution, although you can always grab the WD-40. These old cars weren't as quiet as they are now, so you also may need to adjust your expectations down a notch.

 

Good luck with your project.

[LindenBruce 27]

I just did my unit several months ago. I did it myself. If you do have to remove the entire under dash unit for servicing, remember there are THREE, yes THREE, nuts on the engine side of the firewall that need to be removed. Most people get the one at the eleven o'clock position relative to the A/C lines from the engine side. But, they miss the one behind the passenger side cylinder head where you can't see it. The one for the blower assembly is about in the middle of the firewall about 6-8 inches below the export brace. There are also like four more bolts behind the dash that need to come out as well.

 

When I traded a set of 390 GT heads for my unit, the one bracket that is right behind the drain tube was broken and missing. And that's the one nut most people miss.

 

To clean the case's I used a tire brush, some dish soap, and my shower tub and went to work. After the cases were cleaned up I coated them with a layer of clear coat from dupli color. I taped off the brackets and hit then with my bead blaster and then a coat of clear. Cleaned off all of the old foam gaskets and glued new ones on. Bought new evaporator and heater cores. Then reassembled the unit.

 

But, if you have money and don't have time, the two afore mentioned companies do great work. PM me with your e-mail address and I will send you some pics of what I did. Bruce

[Tripdawg 10]

Thanks for all the great info. I will get to working on it. Hopfully its just a lack of freon issue or a easy to fix leak.

[MikeStang 247]

Bruce,

I would like those pics, I took my box out and tore it down and not sure if i remember how it went together LOL....And getting the heater core out was a Pain in the Nutz, that little metal cross piece was difficult

Mike

[danno 128]

If it is just low on fluid, I am curious if you will attempt to refill with R12? If you were to drive to Mexico, would it be easier to get it filled with R12 there? I fortunately have about 15 cans of R12 that I bought back in about 1992 for 99 cent each on close out. I know you can still get them on ebay, but you have to become a "certified dealer" or something.

 

I have heard the system does not get as cold with R134.

[Tripdawg 10]

Bought a conversion kit from auto zone today. Came with 3 cans of high mileage 134a (134a plus oil) and the adapter fittings. System had pressure, so i figured leaks had to be at a minimum. I put 3 cans of the stuff in and the AC blew cold! Woohoo! I had to engage the compressor clutch manually but I think that is a separate electrical issue. I guess time will tell if the system holds up with 134a. Thanks for the help guys.

[LindenBruce 27]

Bruce,

I would like those pics, I took my box out and tore it down and not sure if i remember how it went together LOL....And getting the heater core out was a Pain in the Nutz, that little metal cross piece was difficult

Mike

 

Hi Mike,

 

Hey, I am having trouble loading up my pics to my profile for you all to see. The size limit is way to small and my pics were taken with a digital camera using high imaghe levels. PM me with your e-mail address and will send them directly. Bruce

[LindenBruce 27]

Bruce,

I would like those pics, I took my box out and tore it down and not sure if i remember how it went together LOL....And getting the heater core out was a Pain in the Nutz, that little metal cross piece was difficult

Mike

 

Mike,

 

I was able to add those pics to my album. Take a look and see if any help you out. I didn't take any pics of the interior as I was putting the pieces back in. I guess I should have huh? I have others I can send too if you like. Especially of my registers at each end of the dash. Those came out great!! I had Auto Instruments re-chrome my vent balls and I did the rest of the work.

 

Anyway, go to Classic Auto Airs' web page and you can look up the case diagrams so you can see how it all goes back together. I know, because I had to do the same thing. I tried to find the link to paste it here, but for the life of me I was not able to.

 

The cross piece you are talking about, it that the rectangular piece of metal holding the heater core down? Because mine was a pain to get back in too. Bruce