64 Riviera A/C Vacuum issues

[SurfGreen64]

Hello fellow lovers of Rivieras,

I am hoping someone may be able to point me in the right direction as I try to figure out why neither of the dual stage vacuum diaphragms on my 64 Riviera do much, if anything!

Here are things to note:

1. I know it seems simple that there may be a lack of vacuum, but I have tested the storage "ball" in the engine compartment and it is keeping a strong solid vacuum.
2. I have then tested the control head connections for both the Heater and A/C and they seem to be getting vacuum although I did not record the PSI.   But when testing them back at the diaphragms, there seems to be less vacuum (I should have records the PSI there also).☹️   Does the PSI split between the dual stages? 
3. The disc switches in the control heads seem to be moving correctly, not binding.
4. The vacuum modulator (lower lever in the A/C head) seems to change the vacuum as it's moved from around 6 PSI at "Low" to no vacuum at full cold with fan on high, which seems to be correct for the suction throttle valve to work correctly.
5. I tested the Heater/Evaporator door diaphragm by using the full force of the vacuum directly from the engine at the two inputs and it did open fully, but needed a little push from my hand.
6. The Air Conditioning control head's rubber adapter was missing and so, someone connected the 4 hoses directly to the numbered "prongs" on the bottom of the control head.

 

So I am wondering what could be causing this, but have some ideas:

1) The missing adapter for the A/C is the culprit as it's not directing the vacuum correctly?

1) The discs that direct the vacuum in the control heads are "shot" (I hope this is not true).

2)  Both the dual stage diaphragms need to be replaced as they are too tight to be moved by the vacuum.

3) There is a some "major" leak in one of the vacuum lines that I can't see.

 

Anyone have some direction to help me?  I appreciate any thoughts.

 

Thank you!

Walt

 

[KongaMan]

4 hours ago, SurfGreen64 said:

2)  Both the dual stage diaphragms need to be replaced as they are too tight to be moved by the vacuum.

 

The diaphragms don't get tight.  However, the doors that they operate do.

 

First step is to test that the diaphragms hold vacuum (as you've done with  the heater door): Put a longish piece of vacuum tubing on one port of the diaphragm, plug the other port with your finger, then suck on the hose.  Does it hold vacuum?  Does the actuating lever move?  Switch the hose to the other port, plug the open port, and repeat.  Put a T in the hose, then connect it to both ports on the diaphragm.  Does the lever move further?  Test the other diaphragm the same way.  You're testing two different things here: the diaphragm's ability to hold vacuum, and the mechanical operation of the door.  If it doesn't hold vacuum, the diaphragm's bad.  If it holds vacuum but nothing moves, the door or linkage is binding. If it holds vacuum and the door moves, you've likely got a leak upstream.

 

You'll hate to hear this, but after 50 years it probably wouldn't hurt to disassemble the blower box so you can clean, lube, and check the seals on the various hinges and doors inside and around the edge.

 

And as long as you're in the area, make sure your heater valve is working freely.

[SurfGreen64]

Thanks very much KongaMan!  

This gives me a place to start.  But one thing, is it OK that the rubber adapters used in the control heads can be bypassed and the vacuum lines plugged directly into them?

[RivNut]

Check to make sure that the "rubber adapter" is not some kind of distribution block.

[Turbinator]

On 5/31/2018 at 1:47 AM, KongaMan said:

 

The diaphragms don't get tight.  However, the doors that they operate do.

 

First step is to test that the diaphragms hold vacuum (as you've done with  the heater door): Put a longish piece of vacuum tubing on one port of the diaphragm, plug the other port with your finger, then suck on the hose.  Does it hold vacuum?  Does the actuating lever move?  Switch the hose to the other port, plug the open port, and repeat.  Put a T in the hose, then connect it to both ports on the diaphragm.  Does the lever move further?  Test the other diaphragm the same way.  You're testing two different things here: the diaphragm's ability to hold vacuum, and the mechanical operation of the door.  If it doesn't hold vacuum, the diaphragm's bad.  If it holds vacuum but nothing moves, the door or linkage is binding. If it holds vacuum and the door moves, you've likely got a leak upstream.

 

You'll hate to hear this, but after 50 years it probably wouldn't hurt to disassemble the blower box so you can clean, lube, and check the seals on the various hinges and doors inside and around the edge.

 

And as long as you're in the area, make sure your heater valve is working freely.

Mr.KongaMan, Jim Cannon coached me through the vacuum hose proper routing on my 63 Riviera. The vacuum accumulator was tested and performs as designed. For the first time in two years I have air conditioning working very well AND blowing warm/hot when it is needed. My vacuum diaphragm #4 does not work. Jim said plug it. Vacuum diaphragm #3 works, but Jim suggested only use #3 in the fall.

As events were unfolding I saw an on line Buick parts supplier showing vacuum diaphragms for the 63 Buick. I said great I’ll get two vacuum diaphragms and replace #3 and #4. When I received the vacuums they were Vacuum Actuators, not vacuum diaphragms. Would my 63 air conditioning system work with vacuum actuators in place of vacuum diaphragms? Please remember I’m learning as I go along. Thank you Red Riviera Bob

[RivNut]

RRB,

Did you check the OE replacement products that Old Air Products offers?

 

https://www.oldairproducts.com/products/factory-replacement-parts/vacuum-parts

[Turbinator]

12 hours ago, RivNut said:

RRB,

Did you check the OE replacement products that Old Air Products offers?

 

https://www.oldairproducts.com/products/factory-replacement-parts/vacuum-parts

Ed, I did check old air. I have the 23-5905 firmly bolted on my 63 Riv doing a wonderful job. Old Air only has the 23-5905 vacuum Actuator. I already have a spare 23-5905 I bought from Old Air by mistake a while back thinking it would replace vacuum diaphragms 3 and 4.   John Price at Old Air answered my question by responding  the 23-5905 is the only part he sells that will fit the 63 Riviera. Jim cannon told me as events were taking place he did not know of any supplier providing vacuum diaphragms to replace #3 and #4. Jim was right. In the meantime, the supplier was insistent what he shipped was correct for my needs. In my opinion the 23-5905 vacuum actuator that was shipped to me will not replace the parts in place. ( I suspect sales are bad for that outfit. The seller boosted me on shipping and insurance. The seller would not listen to me our phone conversation. The fellow did not want to take the parts back and if he did he would charge 15%  restocking fee. I certainly am no expert on auto air conditioning, but after 3 seasons of struggle with the air conditioning I have some hands on experience.

Ted Riviera Bob

[Turbinator]

On 5/31/2018 at 1:47 AM, KongaMan said:

 

The diaphragms don't get tight.  However, the doors that they operate do.

 

First step is to test that the diaphragms hold vacuum (as you've done with  the heater door): Put a longish piece of vacuum tubing on one port of the diaphragm, plug the other port with your finger, then suck on the hose.  Does it hold vacuum?  Does the actuating lever move?  Switch the hose to the other port, plug the open port, and repeat.  Put a T in the hose, then connect it to both ports on the diaphragm.  Does the lever move further?  Test the other diaphragm the same way.  You're testing two different things here: the diaphragm's ability to hold vacuum, and the mechanical operation of the door.  If it doesn't hold vacuum, the diaphragm's bad.  If it holds vacuum but nothing moves, the door or linkage is binding. If it holds vacuum and the door moves, you've likely got a leak upstream.

 

You'll hate to hear this, but after 50 years it probably wouldn't hurt to disassemble the blower box so you can clean, lube, and check the seals on the various hinges and doors inside and around the edge.

 

And as long as you're in the area, make sure your heater valve is working freely.

In the event both vacuum diaphragms in this discussion  are inoperative what are the next steps? The vacuum diaphragms (with single port) under the heater box are no longer available.

Thank you