<VV> 66 A/C Question

Thu Aug 18 20:52:30 EDT 2016

Frank,

Thanks for the wonderful list. I hit maybe 40-50% of those items. This 
weekend I will address the rest of them. Timothy - by disconnected, what 
I should have said was that the compressor had been off the bracket and 
laying off to the side for several years. The system was never opened, 
in fact it still had some pressure. Before attempting the charge, I had 
removed, cleaned and straightened the condenser fins, repaired all the 
dash cables, repaired the fan switch, ohmed the thermostat, replaced the 
lid switch, added a relay to protect the fan switch, tightened up all 
hose clamps, and ran the vacuum and let it sit overnight.  While 
charging I had the lid down, but not latched as the hoses were just laid 
across the seal. I had not removed the back-up light. Last night I tried 
again, but my pressures were still higher than what Cliff listed in his 
reply (Thanks Cliff), so when I make more repairs this weekend I will 
bleed down again, pull a vacuum, and start over. I have been using 
what's left over in a 30# can of R-12, so not entirely sure how much was 
put in, but sure didn't seem like much. I'll use a scale next time.

And yes, Bob, you are correct - this is an excellent list! I should have 
posed my questions the first night!

Thanks all - I'll keep you posted on the progress.

Garry

On 8/17/2016 10:55 PM, Frank DuVal via VirtualVairs wrote:
> Notes:
>
> 1. Engine compartment must be sealed up on 66, 67 models. Tape rust 
> holes! That worked for me...
>
> 2. Remove backup lamp assembly and run hoses through the hole, tape 
> openings closed.
>
> 3. Sight glass should run clear when the charge is enough (or too 
> much!), while compressor is running.
>
> 4. White bubbles usually means not enough R-12 yet. How many pounds 
> have you put in? Note, some cans are only 12 ounces. System holds 
> about 4.5 pounds.
>
> 5. Tighten the belt. 200 psi is nothing in high temperatures. If it is 
> squealing at 200 psi, something is wrong, start with loose belt. There 
> is a reason there are so many braces on the old A-6 compressor. Clutch 
> should easily handle 350 psi, but hope you never see that. If it slips 
> at 200 psi, it is bad.
>
> 6. I do not have a set of gauges in front of me, but the low pressure 
> side should run about 35 degrees F. , whatever pressure equals that on 
> the gauge face. Anything lower than 35 and the evaporator can freeze 
> up. Or so.... AT least the center dash outlet should not be below 35 
> degrees F. Shoot for high 30s to 40.
>
> 7. Temperature is actually controlled by thermostat cycling the 
> compressor, but the charge has to be near correct for that to operate 
> properly.
>
> 8. The rubber seals on top and bottom of condenser are very important. 
> So is taking the condenser off the firewall and cleaning all the 
> leaves/junk out from behind it. Also blow through the condenser to 
> clean the fins. And comb the fins where they usually get flattened.
>
> 9. If you run the compressor with the engine lid open, pressure will 
> get too high and rupture a hose or worse. Note, this can cause 
> blindness if refrigerant gets in your eyes.
>
> 10. Old seat of pants rule, if sight glass runs clear with compressor 
> on, then bubbles form about 2-5 seconds after compressor cycles off, 
> charge is fine.
>
> 11. If center outlet temperature is high, low pressure is high, and 
> sight glass does not get bubbles after compressor shuts off, system is 
> overcharged. Hopefully you never get that far.
>
>
> Others may have different rules or observations...
>
> Frank DuVal
>
>
>
> On 8/17/2016 9:14 PM, Garry via VirtualVairs wrote:
>> Hi all,
>>
>>
>> Questions for all the A/C gurus out there. My 66 110hp/pg Monza with 
>> factory A/C won't cool. The system was disconnected, but still 
>> sealed, with pressure, for  few years, and I am slowly putting it 
>> back together. Tonight was final recharge night. Pulled a successful 
>> vacuum last night, which held, and added a charge, and got not 
>> cooling, but it was too late to continue the diagnostics. I wanted to 
>> finish charging tonight. The ambient temp is approx. 78 degrees, and 
>> my static pressure was 80psi. I don't have a 66 service manual, so I 
>> tried the numbers in the 65 manual. At approx. 2000 rpm, with the 
>> deck lid closed, I get 20 on the low and 130 on the high. Bumping 
>> just a few seconds of charge raised the numbers to 24/145. Output 
>> temp is at 80 degrees, so nothing yet. If I increase the pressure to 
>> about 40/200 the clutch begins to squeal. I see what looks like white 
>> liquid, fairly solid in the sight glass (could be bubbles?), but not 
>> sure exactly what pressure I should see at this outside temp. I did 
>> find the two seals on the condenser are missing, so I'll replace 
>> those tomorrow, and the deck lid seal is good, but I'm sure there are 
>> probably some small leaks around the engine seal - oh and the 
>> summer/winter plate is missing. Other than the obvious things 
>> mentioned - any ideas? I've been out of the R-12 world for way too 
>> many years.
>>
>>
>> Garry Parsley
>>
>
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