AC work

[RivVrgn]

Greetings all, recently purchased a nice 65, all original. Joined ROA, and have really gotten a lot of info from forums,tech articles, and advisors(thanks Tom Mooney).Now trying to bring AC back to life (now that it's 100 degrees). A few questions,compressor runs and fan works but not cold. (probably needs a charge). Blows on floor in normal mode not dash vents. Took fan out, check door diaphram, it works. One on outside if I unhook the arm and move it manually air comes out dash. There is also vacuum from line going to it if I unhook it. Does that mean the diaphram is bad? Also there are bubbles in the sight glass on top of the dehydrator(is this same thing as dryer) when air is on,does that mean I have a leak?I have access to R-12 and when I charge it I don't want to lose my charge? Is there a dye you can use to find a leak? and are there any parts I need to replace that get wornout with age, like o-rings or the dehydrator? Thanks in advance. sorry for the long post hope it makes sense.

Joey M. ROA# 12735

[bob71GS]

Hi Joey and welcome to the ROA.

[

Also there are bubbles in the sight glass on top of the dehydrator(is this same thing as dryer) when air is on,does that mean I have a leak?I have access to R-12 and when I charge it I don't want to lose my charge? Is there a dye you can use to find a leak?

While i'm not the Technical Advisor on the 65 models, I can tell you that the bubbles in the sight glass indicates that you are low on freon. What you are referring to is the receiver/dehydator. Yes there are "O" rings that may need replacing. As far as I know, the leak test kits that are available are for 134 only. Unless you are A/C certified and have all the equipment, I would advise that you take it to a shop that specializes in A/C repairs. It will be worth the money to have it properly repaired with no problems.

Bob Bonto ROA #277

Technical Advisor 71-73

[RivNut]

Here's a copy/pasted page from Chip Little's website that explains how Buick's dual diaphragms work. From what you're describing, it sounds like only half of one of your diaprhagms is working.

'63-'65 Riviera dual-stage diaphragms

[Guest pfloro]

Hi Joey:

Bob is correct. Bubbles in the sight glass indicate a low charge. Assuming that the condenser (in front of radiator) & evaporator (at firewall) are sound and that the rubber hose assembly at the compressor is not leaking, the leak may be at the compressor shaft seal. This seal is lubricated by the mineral oil carried via the R-12. If the system has not been run regularly, this seal will dry out over time.

UV dye can be added to an R-12 system to find leaks. Have a qualified A/C shop recover whatever R-12 is left in the system (required by law). They will then evacuate the system (pull a strong vacuum). This not only boils off any H2O in the system but allows them to see if any major leaks exist. They will hold this vacuum (~30in/Hg) for perhaps 30 minutes. If it holds, they will then charge the system (adding UV dye) and see if any leaks exist. An automotive R-12 system can easily develop 230+psi on the high side. That's why a holding vacuum won't show smaller leaks.

If you have leaks & need to empty the system, it would be a good idea to open each hard line connection & replace the 'O' rings and to change the compressor seal. If they're not leaking now, they may leak when you again begin using the system. It may cost a bit more up front but I'm a believer in: 'do it once, do it right'.

IMHO, I would caution you against converting the system to R-134a. It can sometimes cause a lot of headaches (leaks & poor cooling performance, especially at idle). I've read that R-12 may be getting cheaper since demand is down. My ace mechanic who I fully trust says: "Stay with the refrigerant the system was originally designed to use". That's what I did with my '84 Toronado.

The 'dehydrator' (drier/receiver) doesn't wear out but the desiccant can become contaminated. This usually happens when a compressor fails & sends metal particles through the entire system. The desiccant material can be the same as the stuff (silica gel) in those little bags which state: Do Not Eat...! Ask the shop if they recommend replacing the drier...

Good Luck & Keep us posted.

Paul

Edited August 12, 2010 by pfloro (see edit history)

[RivVrgn]

what'd I say? WEALTH OF INFORMATION! Great info guys many thanks. Got some follow up questions. I thought they quit making R-12? I guess just not in quantitys as before. I believe the same way,do it right the first time and do it once.

the seal in the compressor, can I do that myself, is it in the shop manual and will I need to evacuate the system first?

I guess I'll replace the diaphram and go from there with the coolant fix. Will it be dificult to find a shop that works on R-12?

Edited August 12, 2010 by RivVrgn (see edit history)

[Guest pfloro]

R-12 hasn't been manufactured in this country for maybe 15 years. However, there is still virgin R-12 available which can be legally sold to someone with a refrigeration license. I believe that reclaimed R-12 is 'remanufactured' and also available for sale. I don't know about it's purity.

I suspect that special tools are required to change the compressor shaft seal on the Frigidaire A6 compressor (a very reliable but heavy unit). Your shop manual will indicate what tool(s) are required.

I'm 99.9% sure you'll need to have an empty system in order to change the seal. Hey..., that's why the seal is there in the first place...!

Although, the procedures are similiar, working with R-12 is different than working with R-134a. Be sure the A/C shop knows what they are doing. You may be better off going to a general automotive repair shop than a shop which just services A/C (and changes oil). Keep in mind that no American auto has used R-12 since 1993 (or '94?). How may of those are rolling into A/C shops for service??? Scary!

Keep us posted,

Paul

[bob71GS]

Yes Paul is correct that R-12 has not been manufactured since 1994. Only someone with the A/C certification can obtain R-12. Yes you will need to evacuate the system to work on it. Do you have an evacuating equipment to do this? When you start loosing any of the connections, the R-12 will go out into the air and it will be gone. Bite the bullet and take it to a shop that specializes in A/C repair, it will be well worth the money. I would call around and check first to make sure they can work on R-12. Like Paul said, stay away from shops that just want to check the system VS a shop that specializes in A/C repair.

Bob Bonto # 277 ROA

Technical Advisor 71-73:)

[bb1970]

Hey Joey, Keep an eye on Craigslist for freon. I bought some R-12 last summer for $15 a can (1lb. can). I bought all the dude had. There are still guys that stock up back when. Just make sure all the cans are full.

Bill

[Bill Stoneberg]

Yes you can find it, I ran across 30 LB's of it for a reasonable price on craigslist.

I just looked and I saw multiple listings from 20 a 12 oz can to 425 for 30 lbs.

I had converted to r-134 but was never happy, so now I am back to r-12 and my wife needs a blanket. 38 degrees coming out the vent...

Edited August 15, 2010 by Bill Stoneberg (see edit history)

[RivVrgn]

my wife needs a blanket. 38 degrees coming out the vent...

Thats what i'm after when I complete this repair. I want it to frost my face ha ha. :cool: I'm realistic, I just want a nice functional system,I've already replaced the radiator,waterpump,fan, clutch, thermostat and hoses. Frostys next.