63 Air Conditioning

[Zimm63]

I have been following the various threads on Bob's AC work and found them very informative.  My AC is working, but not well.  The control issue I have narrowed down to a vacuum switch, but the level ov cooling is not what it needs to be either.  

 

Today, I drove the car about 40 miles early on a very humid morning.  I cooled OK, but I noticed condensation on the vents when I slowed down going through a town.  What is the likely cause of this?

 

Returning on a 90 degree day, the AC was cool, but not really comfortable.  

 

Low charge?  Over charge?  Thoughts?

 

 

[KongaMan]

Condensation is likely from cold vents and humid air in the cabin.  When you're driving more slowly, the air through the vents won't cool or dehumidify as well.

 

Look for bubbles in the drier glass.  If there's a steady stream, you're likely low on refrigerant.  If not, buy gauges and a thermometer.  Check pressures and outlet temperature.  Also check your heater valve to make sure it's completely shut and the doors to make sure that airflow is correct (i.e. you're not drawing uncooled outside air through).  Make sure your kick panels vents are closed as well.

[5632]

I have had no personal experience on 63 - 65 Riviera A/C but have been told by someone that has great experience on older cars that the riviera system is very poor and worst he has seen.  Thats why I am updating  mine to a new Vintage Air system that uses new technology and looks so much nicer under the hood.  I am a user not a purest.  If you want any under hood A/C parts I will contribute them for free.  

[Jim Cannon]

14 hours ago, Zimm63 said:

I have been following the various threads on Bob's AC work and found them very informative.  My AC is working, but not well.  The control issue I have narrowed down to a vacuum switch, but the level ov cooling is not what it needs to be either.  

 

Today, I drove the car about 40 miles early on a very humid morning.  I cooled OK, but I noticed condensation on the vents when I slowed down going through a town.  What is the likely cause of this?

 

Returning on a 90 degree day, the AC was cool, but not really comfortable.  

 

Low charge?  Over charge?  Thoughts?

 

 

Make sure that your condensate drain lines are both open and that condensate is coming out of both of them.  If not, you accumulate a lot of water in the evaporator box and trap that humidity into the car.  Get under the car while the A/C is running and look from water dripping from both drain lines (under the fan box, behind the right front wheel, but inboard a bit).

 

It is impossible to say with certainty if you have under charge or over charge from the information given.  You must read pressures under the hood while the engine is running and he A/C is on high fan speed and in the maximum cooling position.  But I can guess.

 

These systems tend to leak slowly.  They did this when they were new.  Freon was cheap and topping up each spring was part of routine maintenance.  This is before they knew about the hole in the ozone layer.  So, if I had to guess, I'd say that your system is low unless you have added freon to the system lately.

 

The fact that you are getting any cooling at all is a good sign.

 

When freon is low in a system, it is common for the evaporator core to freeze up.  This is counterintuitive, but that's the way it works.  When the evaporator core freezes up, you seriously lose cooling capacity, and you trap a lot of water (in the form of ice) in the evaporator box.  Later when you slow down, this ice melts and put a lot of moisture in the air coming out of the vents, hence the water on the vents.

 

Don't just add freon.  Use gauges and put in the correct amount.

 

 

 

[Hearse]

Doesn't he have to make sure he has the proper amount of oil in there as well? i thought when r12 leaks it takes the oil with it. 

[Turbinator]

Yes, I still read the mobile AC manuals I have. Science class. The more you know how the thing works the better chance you have of beginning your diagnostics. I could not get R12 to go into the system. The short- Tom Telesco checked each connection under the hood starting at the condenser to see if he had pressure. At the connection near the AC muffler no pressure. Come to find the blockage was too much oil from previous efforts in the AC muffler!

Tom drained the oil out of the muffler. The AC took a charge. I have cold air, but not quite cold enough. 42 F is the coldest I’ve had. Tom T and I have a plan over the next few weeks to check for leaks. Also the system may be overcharged. We will see.

Turbinator

[Turbinator]

5 hours ago, Jim Cannon said:

Make sure that your condensate drain lines are both open and that condensate is coming out of both of them.  If not, you accumulate a lot of water in the evaporator box and trap that humidity into the car.  Get under the car while the A/C is running and look from water dripping from both drain lines (under the fan box, behind the right front wheel, but inboard a bit).

 

It is impossible to say with certainty if you have under charge or over charge from the information given.  You must read pressures under the hood while the engine is running and he A/C is on high fan speed and in the maximum cooling position.  But I can guess.

 

These systems tend to leak slowly.  They did this when they were new.  Freon was cheap and topping up each spring was part of routine maintenance.  This is before they knew about the hole in the ozone layer.  So, if I had to guess, I'd say that your system is low unless you have added freon to the system lately.

 

The fact that you are getting any cooling at all is a good sign.

 

When freon is low in a system, it is common for the evaporator core to freeze up.  This is counterintuitive, but that's the way it works.  When the evaporator core freezes up, you seriously lose cooling capacity, and you trap a lot of water (in the form of ice) in the evaporator box.  Later when you slow down, this ice melts and put a lot of moisture in the air coming out of the vents, hence the water on the vents.

 

Don't just add freon.  Use gauges and put in the correct amount.

 

 

 

The correct amount of Freon charge is determined by what is shown in the 1963 Buick Service Manual sec 11 AC. The ambient temp is the bench mark for beginning of what the high and low side should read. Some charge with the gas until the bubbles go away in the sight glass, then add about 6 Oz more. Seems to me 63 Riviera AC is an art as well as a science. Admittedly, I have been consulting a lady that practices Voo Doo in hopes of getting some luck. She sent an amulet in the mail I put the amulet around the compressor.

Turbinator

[Jim Cannon]

Charging until you don't see bubbles in the sight glass is a bad idea. You can over charge doing that. The sight glass is good for a quick visual check of the system, but is not intended to determine if you have the correct charge.  Use the gauges and the pressures published in the shop manual.  It is easy to overcharge.

 

Another key to good cooling is a good condenser in front of the radiator. If the original condenser is not cooling the hot gas back down to a cool liquid, you will not get good cooling inside the car.  Put a box fan blowing on high speed in front of the car's front grill, blowing into the engine.  Use your fingers to see how hot the outlet tube is coming off of the condenser, going into the filter-drier.  If it is almost too hot to grip the pipe between thumb and first finger, the condenser is not doing its job.   I replaced my 50 year old condenser and stayed with R-12.

 

The amount of oil lost with the freon when it leaks out at the compressor seal is trivial.  You should not attempt to try to replace it or you will overload the system with oil. Don't worry about it.  Oil is only added when a component is replaced.

 

 

[Turbinator]

Jim, the condenser is new. Hopefully it is working correctly.

i do have a fan for the functional testing as outlined in Service Manual. I do the test you have described.

i have read about charging and watching the sight glass. Tom Telesco was heading up this rodeo

so I watched and kept quiet. I deferred to Tom’s experience and “ art” part of AC mechanics. After all it was me that talked Tom into the long drive to Lutherville to help.

We did feed Tom pretty good and his room and bath were not bad.

I am considering the severe duty fan clutch in hopes of drawing more air over the evaporator. Traffic jams in Baltimore/DC corridor I believe rank some place as the worst for driving.

The middle vent adjustment was a piece of cake to get air flowing. I have a lead on some very inexpensive 14 Oz cans of R12. Think I’ll load up.

Turbinator

[Turbinator]

On 7/5/2019 at 9:27 PM, 5632 said:

I have had no personal experience on 63 - 65 Riviera A/C but have been told by someone that has great experience on older cars that the riviera system is very poor and worst he has seen.  Thats why I am updating  mine to a new Vintage Air system that uses new technology and looks so much nicer under the hood.  I am a user not a purest.  If you want any under hood A/C parts I will contribute them for free.  

Sir, you are fortunate to know these facts. I applaud your good sense. I would whole heartedly encourage you to do your due diligence when hiring a shop or person to make sure they know what they are doing. I suspect some shops in hotter areas of the country have experience with this type of work. Had I known what I know now I would have given an after market AC serious consideration. I’m not a purist in my restoration efforts. For instance I run radial tires, zBilstein shocks, custom exhaust, but everything else is a replacement for what came with the car. 

Thank you

Bob

[Turbinator]

Here we are 2023 and at least 4 years since my last missive ( I think ) regarding 1963 Riv AC. I’m not at home right now but thinking that my kick panel vents are not closed might be why I’m not getting cold air. When I return to my “ Carriage House” where I store my Riviera I’ll close the kick panel vents and see if that is my AC problem.

if not the problem I’ll get out the the 63 Manual and read the manual and begin functional AC tests. Stay tuned.

Turbinator

 

Just haven't been able to clear my schedule to get on the AC. Seems like my "Scheduler" has other priorities about the property upkeep. So I just swelter outside in the heat and in the Riv with the window rolled down. I'll get it squared away here directly.

Edited July 28, 2023 by Turbinator (see edit history)

[MrFreeze]

I am currently trying to get the AC operational in my '64, so I will be looking forward to your updates.  Good luck.

 

MrFreeze

[atencioee]

I appreciate these posts... very informative and helpful. Haven't got to my AC yet, but it's on the list!