63 Unidentified AC Component

[tkeiser1]

Okay, I'm slowly working on getting my ac working. I'm about to remove the compressor to refill the oil and noticed a component that I had not noticed previously. As you can see from the picture, it is located between the high side of the compressor and the condenser. I certainly looks like an original part but my shop manual does not show in any diagrams and I've been unable to find any mention of it in the narrative. Can someone help me?

Thanks,

Tom

[steelman]

This is an AC muffler. Used to quiet the air conditioner further. Yes, it is factory. All Rivieras with AC had these.

[tkeiser1]

Thanks, Steve. Do you by any chance know where I can find it in the manual. I'd like to read up on it.

Tom

[Jim Cannon]

You won't find the muffler in the '63 shop manual because it was introduced after the shop manual went to the printers.   Not all '63 Rivs had an A/C muffler!  Early in the production of the car, they decided that the compressor was making too much noise under the hood while driving.  So they added this muffler on cars with A/C made in the 3rd week of October, 1962, and later (around FB 4000 and later).   

 

 

Edited September 24, 2018 by Jim Cannon (see edit history)

[steelman]

Thanks, Jim. I wasn't aware this was also one of the 63 running changes.

[Seafoam65]

The compressor on your car is 56 years old .There is zero probability that it is both functioning and not leaking out the front when charged.

Don't waste your time messing with it......you need a new one.

[tkeiser1]

55 minutes ago, Seafoam65 said:

The compressor on your car is 56 years old .There is zero probability that it is both functioning and not leaking out the front when charged.

Don't waste your time messing with it......you need a new one.

I'm still hoping. Actually, before I took the system apart, the compressor was running and the system was holding vacuum. It wouldn't cool because the expansion valve was completely blocked. SO . . . I'm keeping my fingers crossed. 

[KongaMan]

Bear in mind that the A6 always did leak a little, even when new.  The important question is not if it leaks, but how much.  If you're slinging oil around your engine compartment (look for the line on the hood), that's probably too much.  

 

The best thing you can do for these compressors is run them.  You run them to keep the front seal lubricated and flexible.  They get lubed by oil that leaks out.  They're supposed to work that way.

[Seafoam65]

                  My 69 GTO developed a stopped up expansion valve back in 1974 because the system was contaminated with moisture due

to incompetence on the assembly line not pumping the system down long enough. On my GTO I wound up having to replace the entire 

system because it would plug up the expansion valve once a month. Once I changed out everything and pumped it down for 24 hours and charged it, it's been fine ever since. As for the 56 year old compressor, if it doesn't dump freon out the front seal when you start using it it would be a miracle tantamount to the parting of the RED SEA.

Edited September 24, 2018 by Seafoam65 (see edit history)

[tkeiser1]

2 minutes ago, Seafoam65 said:

                  My 69 GTO developed a stopped up expansion valve back in 1974 because the system was contaminated with moisture due

to incompetence on the assembly line not pumping the system down long enough. On my GTO I wound up having to replace the entire 

system because it would plug up the expansion valve once a month. Once I changed out everything and pumped it down for 24 hours and charged it, it's been fine ever since.

Ugh!!  As I'm working on this car I'm finding a lot of poor quality maintenance work, even though it only has 63,000 miles on it. The AC was one example. It seems that a couple of components were replaced and it was updated to R134. However, because the expansion valve was hard to get to, they didn't bother. When I removed it, it was full of "gunk," so much so that it completely blocked the system. The lines going into it were full of crud while the lines coming out of the evaporator were clear. Even the STV appears clean. I'm not a mechanic, but I learned to distrust mechanics so much that when something needs to be fixed, I'll educate myself and then do it myself, if at all possible.  

[Seafoam65]

There are two sources of "gunk"  in your A/C system. The first source that I outlined above is a white powder that looks like baking soda

which is caused by the moisture and freon forming an acid that eats away at the aluminum A/C parts and makes a white powder that stops up the expansion valve. Generally that stuff won't flush out, at least it didn't on my GTO. The second source of gunk is when somebody pounds R134A

into an R12  system without first flushing out the old R12 oil and replacing with R134A compatible oil. This creates a  

dark colored gunk. Generally that stuff won't flush out either and requires replacing all the parts on the system. 

[tkeiser1]

This was brown, mud-like, and flushed nicely out of all the components.  Reminded me of wet rust. Any ideas what that was?

Edited September 24, 2018 by tkeiser1 (see edit history)

[Seafoam65]

               That's the mud that is formed by adding R134A without changing out the refrigerant oil.

[tkeiser1]

More evidence of a half-way job!!  The car was owned by an old lady, who obviously was taken advantage of. 

[1965rivgs]

On 9/23/2018 at 5:51 PM, tkeiser1 said:

Okay, I'm slowly working on getting my ac working. I'm about to remove the compressor to refill the oil and noticed a component that I had not noticed previously. As you can see from the picture, it is located between the high side of the compressor and the condenser. I certainly looks like an original part but my shop manual does not show in any diagrams and I've been unable to find any mention of it in the narrative. Can someone help me?

Thanks,

Tom

Hi Tom,

  What is the refrigerant capacity for the Riviera listed on the metal tag affixed to your compressor?? Can you post a legible pic? Thanks,

Tom Mooney

[Turbinator]

On 9/24/2018 at 7:16 PM, tkeiser1 said:

Ugh!!  As I'm working on this car I'm finding a lot of poor quality maintenance work, even though it only has 63,000 miles on it. The AC was one example. It seems that a couple of components were replaced and it was updated to R134. However, because the expansion valve was hard to get to, they didn't bother. When I removed it, it was full of "gunk," so much so that it completely blocked the system. The lines going into it were full of crud while the lines coming out of the evaporator were clear. Even the STV appears clean. I'm not a mechanic, but I learned to distrust mechanics so much that when something needs to be fixed, I'll educate myself and then do it myself, if at all possible.  

I agree with your thoughts about mechanics in auto shops. I do believe there are some mechanics that are outstanding. The outstanding mechanics are very hard to find.

i rebuilt my 63 AC system with new replacement parts with exception of the condenser and vacuum modulator. No mechanic nor I could find out why my AC air was not very cool. Decided to replace with all new parts AND continue with R12. From what I’ve read the original evaporator was not designed for 134a.

Hopefully, your abilities and diagnostics will quickly lead you to solutions for your AC. I could not find any AC mechanics in central MD that could repair on my AC. So, I’ll fix it myself, maybe.

RRB

 

[Turbinator]

On 9/25/2018 at 2:41 AM, 1965rivgs said:

Hi Tom,

  What is the refrigerant capacity for the Riviera listed on the metal tag affixed to your compressor?? Can you post a legible pic? Thanks,

Tom Mooney

Tom, here is my legible pic of the original compressor on my 63 Riviera.

[tkeiser1]

On 9/24/2018 at 9:41 PM, 1965rivgs said:

Hi Tom,

  What is the refrigerant capacity for the Riviera listed on the metal tag affixed to your compressor?? Can you post a legible pic? Thanks,

Tom Mooney

Here it is.

[1965rivgs]

  Thanks for posting the pics gentlemen.

  Reason I asked Keiser is because the stated charge on the `63 compressor without the muffler is significantly smaller as compared to the later `64-`65 cars which are equipped with the muffler. I suspected the reason the charge amount was stepped up in the later versions may have been that Buick added the muffler to the system. But it appears, even if this is the reason, that Buick didnt change the charge specs on the compressor tag.

  Perhaps it is possible, even if the reason for the change in charge IS the addition of the muffler, Buick didnt change the spec on the compressor. Interesting that they did away with the impossible to change metal tag and changed to an easy to change decal in the later cars??

  Interesting....

Tom Mooney

[1965rivgs]

  Jim Cannon, do you have anything to add regarding the change in system charge as it relates to the addition of the muffler to the system? Thanks,

Tom

[telriv]

IMHO I don't think that the muffler would add 1/2pd. of Freon.  In the '63 chassis manual it states 3.5 for 4700 & 4 for all the rest of the BIG cars.  AND, it states the same in the '64 chassis manual.  AND, as we know ALL A/C equipped big cars ALL had the mufflers by '64.  As far as I know there is NO significant diff. in the size or length of components to warrant this.   MAYBE they decided that 3.5 wasn't enough to begin with.

You MUST pay attention to the pressures & the way temp. & humidity affects the outcome.

 

Just my thoughts on the subject.

 

Tom T.

 

 

[tkeiser1]

Very interesting . . . and informative for a newby. It will be interesting to see what Jim has to say.

[60FlatTop]

The muffler is on the vapor side, not much in terms of the total liquid charge.

 

[1965rivgs]

7 hours ago, telriv said:

IMHO I don't think that the muffler would add 1/2pd. of Freon.  In the '63 chassis manual it states 3.5 for 4700 & 4 for all the rest of the BIG cars.  AND, it states the same in the '64 chassis manual.  AND, as we know ALL A/C equipped big cars ALL had the mufflers by '64.  As far as I know there is NO significant diff. in the size or length of components to warrant this.   MAYBE they decided that 3.5 wasn't enough to begin with.

You MUST pay attention to the pressures & the way temp. & humidity affects the outcome.

 

Just my thoughts on the subject.

 

Tom T.

 

 

Tom,

  The spec for the `65 cars is 3.75 pounds so 1/4lb more than the `63-`64 cars.

  Tom

[1965rivgs]

5 hours ago, 60FlatTop said:

The muffler is on the vapor side, not much in terms of the total liquid charge.

 

Bernie,

  I am not a refrigeration engineer so am not familiar with system specs/charge volume but just curious..would a larger system volume on the vapor side reduce the volume of liquid refrigerant available at the expansion valve?

Tom

[60FlatTop]

It is just the difference in volume between the gas and the liquid. The gas is the liquid expanded by about 1000 times per unit, a little liquid makes a lot of gas.

The volume of liquid at the expansion valve is dependent on the liquid refrigerant leaving the condenser, its pressure, and the amount of subcooling. The addition of the muffler between the compressor and condenser would not make a significant difference in charge requirements.

My background is commercial and industrial. I have never done anything more than add a little charge to a car. The principles are the same but details of a field will trip up someone crossing over.

 

I was surprised to see the picture of the muffler with hose clamps on the high side. That's where a common practice in one field becomes a double take to someone with training in another field. I am better off making some money on a commercial job and hiring a real automotive guy to fix my car........ same with my home furnace, I can run a boiler bigger than my house, but if I tried to fix my home heat I might burn the house down.

Bernie

[Jim Cannon]

On 9/26/2018 at 9:11 AM, 1965rivgs said:

  Jim Cannon, do you have anything to add regarding the change in system charge as it relates to the addition of the muffler to the system? Thanks,

Tom

 

I do not remember seeing anything about a change in the charge volume in any of the Service Bulletins. 

 

This part of the system is filled with hot gas when running.  That volume is peanuts, compared to the liquid side out of the condenser and up to the expansion valve.  I would not worry about it.  All you have done is move the gas/liquid boundary a few inches down in the condenser.  As long as you still have liquid coming out of the condenser, you are good. 

 

As Tom Telesco said, you watch the pressure gauges, they tell you when you have it right. Most guys overcharge the system anyway.

 

[Jim Cannon]

19 hours ago, 60FlatTop said:

It is just the difference in volume between the gas and the liquid. The gas is the liquid expanded by about 1000 times per unit, a little liquid makes a lot of gas.

The volume of liquid at the expansion valve is dependent on the liquid refrigerant leaving the condenser, its pressure, and the amount of subcooling. The addition of the muffler between the compressor and condenser would not make a significant difference in charge requirements.

My background is commercial and industrial. I have never done anything more than add a little charge to a car. The principles are the same but details of a field will trip up someone crossing over.

 

I was surprised to see the picture of the muffler with hose clamps on the high side. That's where a common practice in one field becomes a double take to someone with training in another field. I am better off making some money on a commercial job and hiring a real automotive guy to fix my car........ same with my home furnace, I can run a boiler bigger than my house, but if I tried to fix my home heat I might burn the house down.

Bernie

 

Bernie is right.  At the temperatures and pressures that we run the automotive A/C, saturated R-12 has a volume difference between vapor and liquid of about 35:1.  One cubic centimeter of liquid takes up 35 cc of volume when a gas.  So the 70 cubic inches of hot gas in that muffler (my volume estimate -- anyone want to go measure it more carefully?) becomes 2 cubic inches of liquid, which is 1.5 ounces of liquid R-12.   When the charge is given in pounds, this would add less than 0.1 lb, to the system and the engineers knew that was in the round off.  As I said in my other post, that moves the hot gas to liquid transition a few inches down the condenser.  Not a big deal.

 

Isn't Thermodynamics fun?