63 Riviera AC vent doors opening and closing

[Turbinator]

41 minutes ago, 60FlatTop said:

 

Should end "within the paradigm of the application. That is the dangerous part, a little knowledge.

 

In 1983 an electronic accounting application would have lived up to the definition of college level learning, the conceptual use of knowledge from one field to another. I added conceptual from my own 50 years of experience. Details are often overlooked in exchange for commitment.

 

I started using communication circuits in 1974 with token ring technology and some fiber optics. Unshielded cable was fine for binary points. And they were the majority. The cost was about $500 per point compared to analog points at about $2,000 per. Analog used current loops with resistance sensors and were always installed with shielded (tin foil) wire. There just weren't many and may not have been obvious to the application investigator.

 

On the AC, follow the book and make it as original as possible. Back to my personal  experience, my greatest successes have come from recognizing and removing "improvements".

 

 

Bernie, The application met all specifications according to sales marketing pros. The folk in the engineering neglected to tell the sales marketing managers to be aware of radio frequency interference. We were not told about this RFI stuff. Had I known the RFI was something I should know about I'd have called Scotty to the bridge and asked for his two cents worth.The local tech, a friend of mine didn't know if he was on horseback or on foot on this installation. When the installation failed to perform as it was purported to perform and we took the stuff back the local rep did not get a raise that year and I was charged about 6k to my account. Ouch.

After that lesson I made doubly certain all i's  were dotted and the t's were crossed on future scope of application. Please remember, I was schooled on how to read, write, and cypher. The trained folks got all the electronics stuff on how to wrap wires with tin foil. I probably would have been better off learning about electricity than reading Camus.?‍?

[60FlatTop]

Looks like the trained folks saved the day for the pros and schooled literate.

 

I read Asimov and Wells, Vonnegut for fun.

 

Back to the AC, how much is the R-12 going for these days? I'm still working off a 30 pounder I bought at a buck a pound. Lasts a long time when there is no compressor on your car.

 

There could have been quite a market in reclaimed/recycled refrigerants with the right equipment : http://www.freepatentsonline.com/5189889.html

 

 

[Bill Stoneberg]

R 12  It depends on where you shop.  Was at an A/C getting R22 for my home AC and they had a 30 LB container of R12 for $ 1400.   Ebey goes about $800.   I still have the remains of 1 30 lb container and a full container that I bought for $ 400 few years ago. It also lasts long when you fix the leaks.

I have a friend who uses computer duster in his R12 system. Cools well and at 3 bucks a can it is cheap. His car takes 5 cans.  It one of those Buick's with the A/C in the trunk, can you imagine how much R 12 it would take ?  My 1960 takes 5 lbs if empty.

[Turbinator]

21 hours ago, 60FlatTop said:

Looks like the trained folks saved the day for the pros and schooled literate.

 

I read Asimov and Wells, Vonnegut for fun.

 

Back to the AC, how much is the R-12 going for these days? I'm still working off a 30 pounder I bought at a buck a pound. Lasts a long time when there is no compressor on your car.

 

There could have been quite a market in reclaimed/recycled refrigerants with the right equipment : http://www.freepatentsonline.com/5189889.html

 

 

Bernie, those educated engineers saved my bacon plenty.

 

the average for R12 on eBay is $45.-$50. A pound. My friend and pro mechanic handed me two 30 lb partial canisters of R12. He said go ahead and use it. I returned the the 2 30lb containers after I used 3.5lbs and gave him  enough cash that made him smile.

i have 2-12oz. Cans I paid $75.00 with shipping.

[Turbinator]

On 8/18/2017 at 0:00 PM, KongaMan said:

 

Wise decision.  While one might rationalize a switch to R134A, there's no doubt that you'll get better performance with R12.  Replacing the STV with a cycling switch is just half-assery.

I was convinced to stay with the original design and as many OEM parts as possible. AC is important to me and I cannot afford to be without a reliable system. Use best parts, best mechanics, and stay with original design operation.

RRB

 

[Turbinator]

Gents Aug 21. My friend and mechanic finished installing the vacuum hoses, check valve, and vacuum Actuator that open and closes a vent  door. I watched as he cussed his way through the diagrams of what color hose went where. 

I found you've got to use the correct size hose to minimize and/or eliminate leaks. After the leaks were found and fixed the AC worked real good. Plenty of cold air blowing even as I stepped on the gas pedal. It was cold enough I had to turn down the fan motor and amount of cooling. Only took 15 months after I received the car and purportedly the AC worked as it should to get repaired/ rebuilt.

 

Red Riviera Bob

[Bill Stoneberg]

Ask your friend what check valve he got  please...  or did you get it someplace.

[Turbinator]

6 hours ago, Bill Stoneberg said:

Ask your friend what check valve he got  please...  or did you get it someplace.

Bill, I bought a plastic check valve from Old Air and it works fine.

i wanted to stay with the brass check valve for personal preference.

if u have one for sale at a price I can live with let me know what your price is. I don't dicker, either the price is ok or not. You need to make $ on your sales.

Red Riviera Bob

[Bill Stoneberg]

7 hours ago, Red Riviera Bob said:

Bill, I bought a plastic check valve from Old Air and it works fine.

i wanted to stay with the brass check valve for personal preference.

if u have one for sale at a price I can live with let me know what your price is. I don't dicker, either the price is ok or not. You need to make $ on your sales.

Red Riviera Bob

Nope   I have none for sale, just looking for one for my car.   Thanks

[Turbinator]

6 hours ago, Bill Stoneberg said:

Nope   I have none for sale, just looking for one for my car.   Thanks

Bill, those folks at Old Air are very good to deal with on parts, returns, and advice. Thoroughly knowledgeanle. Old Air rebuilt an STV and Actuator for me quickly.

well done. If you need an STV CORE, or turn signal switch for tilt no cornering lights I have one.

Red Riviera Bob

[Turbinator]

On 8/17/2017 at 7:47 AM, Jim Cannon said:

The "double diaphragm" (stacked diaphragms) under the blower motor allowed Buick to have the recirc door (or the "fresh air in" door, if that's what you want to call it) be fully closed when the system is fully off, part open when the A/C is on High fan speed and Max Cooling.  This is as close to fully recirc that Buick offered.  In all of A/C positions and in all modes with heat, the recirc door is fully open (i.e. full fresh air flow from outside).  This is all in the shop manual.  (In today's modern car A/C, they offer full recirc.).

 

Personally, I like having full recirc on my A/C all the time, instead of cooling down the hot, humid outside air in Houston.  So that is why I modified my system to be open for heat (all fresh air) and closed for A/C (full recirc) by having no vacuum applied to either diaphragm (or either port of a 2-port diaphragm, like you use on the plenum on the firewall under the hood).  I don't use the partial open setting at all.

 

The spring pulls the recirc door closed (full recirc -- no outside air) if no vacuum is on a diaphragm under the fan.  Better than what Buick did for cooling.  BTW, they were concerned about carbon monoxide poisoning.  That's why they wanted to bring in the fresh air all the time.  No cat converter on these cars, lots of CO.  Be careful!

 

 

 

 

 

Jim, I have AC now in the 63 Riviera and it is coming in the cabin ok. I believe the performance can be better if I replace JUST one more item.

The diaphragm on the bottom of the stacked diaphragms under the blower doesn't work. Would you happen to know where I might get a diaphragm like the one of the bottom? If, I can 't find the diaphragm on the bottom for replacement I just might do as you have. Have no vacuum applied to the top or bottom diaphragm. From what you have indicated  that might be the way I go. Right now I'm using the top the diaphragm and the bottom one is not working at all.

It was 90 degrees in Baltimore area yesterday and the humidity probably as high. The AC in the Riviera was fine No problems.- However, I'd like to get it right as right can be.

Red Riviera Bob

[Turbinator]

On 8/18/2017 at 1:25 PM, 60FlatTop said:

It is interesting that the nearest city on my map is in another country. Cornell University has a deep water cooling system in Seneca Lake where the water is always 35 degrees.

Bernie, if the water in the lake is 35 degrees seems to me you don't need a cooling system at all, but just a pump to get the 35 degree water where you want to cool something. Im sure there is more to the story, but at first glance it makes me wonder.

Red Riviera Bob

[60FlatTop]

10 minutes ago, Red Riviera Bob said:

at first glance it makes me wonder

 

With the EPA involved it is amazing. There is even a contract with a guy in a rowboat who makes sure the light bulb 250 feet below the surface stays on to keep the fresh water shrimp out of the suction.

 

That's a starter. I got my lakes shifted. It is Cayuga Lake.

 

Internal cooling for buildings is a fairly high demand even though this isn't a warm climate. For cars, it's a yawn. Many cars have steel condenser coils. When the winter salt from the icy roads rots them out most people just stop pushing the snowflake button.

 

In the mid 1990's I had a nice GM compressor appropriate for my Riviera. It floated around my garage for about a decade and a half. Then I think it got tossed during one of the infrequent cleanups.

 

August 23rd, 1 PM, it is 68 degrees. I saw a nice little house on Grand Cayman over the weekend.

 

Bernie

[Jim Cannon]

5 hours ago, Red Riviera Bob said:

Jim, I have AC now in the 63 Riviera and it is coming in the cabin ok. I believe the performance can be better if I replace JUST one more item.

The diaphragm on the bottom of the stacked diaphragms under the blower doesn't work. Would you happen to know where I might get a diaphragm like the one of the bottom? If, I can 't find the diaphragm on the bottom for replacement I just might do as you have. Have no vacuum applied to the top or bottom diaphragm. From what you have indicated  that might be the way I go. Right now I'm using the top the diaphragm and the bottom one is not working at all.

It was 90 degrees in Baltimore area yesterday and the humidity probably as high. The AC in the Riviera was fine No problems.- However, I'd like to get it right as right can be.

Red Riviera Bob

Bob-

I do not know of a source for the double diaphragm unit new.  You could search on eBay.  Put a saved search in the system and have it notify you any time one is listed for sale.  Go by the GM part number.  I have gotten NOS parts this way where the seller did not really know what they had.

 

You can always get a used one off of a parts car.

 

If you know you have a bad diaphragm, plug that vacuum hose with a golf tee or a roofing nail to stop the vacuum leak there until it is replaced.

 

Look in the shop manual, page 11-72.  Your lower diaphragm is identified as #4 diaphragm.  This is the one that holds the recirc (fresh air) door open 1/4 when your A/C is on MAX cooling.  If your diaphragm is not working, you are getting full recirc.  This is what I actually did on my car for MAX cooling.  I put my COOL knob all the way in all the time and move the fan from High to Medium speed if too cold.  I would suggest you not change a thing.

 

MAX cooling means you have the COOL knob is pushed all the way in on the dash.  Anything less than that gives you 100% outside air going through the A/C coils.

 

 

 

 

[Turbinator]

11 hours ago, Jim Cannon said:

Bob-

I do not know of a source for the double diaphragm unit new.  You could search on eBay.  Put a saved search in the system and have it notify you any time one is listed for sale.  Go by the GM part number.  I have gotten NOS parts this way where the seller did not really know what they had.

 

You can always get a used one off of a parts car.

 

If you know you have a bad diaphragm, plug that vacuum hose with a golf tee or a roofing nail to stop the vacuum leak there until it is replaced.

 

Look in the shop manual, page 11-72.  Your lower diaphragm is identified as #4 diaphragm.  This is the one that holds the recirc (fresh air) door open 1/4 when your A/C is on MAX cooling.  If your diaphragm is not working, you are getting full recirc.  This is what I actually did on my car for MAX cooling.  I put my COOL knob all the way in all the time and move the fan from High to Medium speed if too cold.  I would suggest you not change a thing.

 

MAX cooling means you have the COOL knob is pushed all the way in on the dash.  Anything less than that gives you 100% outside air going through the A/C coils.

 

 

 

 

Jim, I've had your answer all along and now that you have told me yet once again I have it as right as it is going to be.

many thanks for your patience and regarded professional advice.

Red Riviera Bob

[Turbinator]

On 8/23/2017 at 1:02 PM, 60FlatTop said:

 

With the EPA involved it is amazing. There is even a contract with a guy in a rowboat who makes sure the light bulb 250 feet below the surface stays on to keep the fresh water shrimp out of the suction.

 

That's a starter. I got my lakes shifted. It is Cayuga Lake.

 

Internal cooling for buildings is a fairly high demand even though this isn't a warm climate. For cars, it's a yawn. Many cars have steel condenser coils. When the winter salt from the icy roads rots them out most people just stop pushing the snowflake button.

 

In the mid 1990's I had a nice GM compressor appropriate for my Riviera. It floated around my garage for about a decade and a half. Then I think it got tossed during one of the infrequent cleanups.

 

August 23rd, 1 PM, it is 68 degrees. I saw a nice little house on Grand Cayman over the weekend.

 

Bernie

 

On 8/23/2017 at 1:02 PM, 60FlatTop said:

 

With the EPA involved it is amazing. There is even a contract with a guy in a rowboat who makes sure the light bulb 250 feet below the surface stays on to keep the fresh water shrimp out of the suction.

 

That's a starter. I got my lakes shifted. It is Cayuga Lake.

 

Internal cooling for buildings is a fairly high demand even though this isn't a warm climate. For cars, it's a yawn. Many cars have steel condenser coils. When the winter salt from the icy roads rots them out most people just stop pushing the snowflake button.

 

In the mid 1990's I had a nice GM compressor appropriate for my Riviera. It floated around my garage for about a decade and a half. Then I think it got tossed during one of the infrequent cleanups.

 

August 23rd, 1 PM, it is 68 degrees. I saw a nice little house on Grand Cayman over the weekend.

 

Bernie

Bernie, the Harrison A6 was working when it was replaced with a NEW A6 style compressor. There was some, not a lot of tell tale grease around the clutch. I just didn't know to chance it or not and I already paid and received the A6. If, you want the Harrison A6 I'll send it up, no problems or worries.

RRB

[Turbinator]

On 8/22/2017 at 0:45 PM, Bill Stoneberg said:

Ask your friend what check valve he got  please...  or did you get it someplace.

Bill, the check valve was purchased from Old Air in Texas. Helpful people at Old Air. Old Air knows what customer service is all about.

Red Riviera Bob

[Turbinator]

On 8/18/2017 at 1:10 PM, KongaMan said:

On the assumption that you're responding to my comment about half-assery, I'll explain...

 

It's important to understand what the STV does and how it works.  In a nutshell, it varies the evaporator pressure, which, in turn, changes the temperature of the outlet air.  It is controlled by the vacuum modulator attached to the temperature control on the dash: the less vacuum at the valve, the lower the evaporator pressure and the lower the outlet air temperature.  Push the control all the way down, the vacuum to the valve drops to 0, the evaporator pressure drops, the air gets colder.  Slide the control back up, the vacuum to the valve rises, the evaporator pressure rises, the air gets warmer.

 

If the STV is replaced by a cycling switch, it's entirely different.  In that setup, the evaporator pressure is always at its lowest setting; the outlet temperature is always as cold as it will go.  The system is cycled according to feedback from a new temperature sensor on the evaporator.  This is how it works: the system runs fullout until the sensor says it's too cold, then the compressor shuts off.  When the sensor indicates it has warmed up, the compressor kicks on again. And so on.  What you may have noticed is that you have no control over this: your temperature control is inoperative.  You cannot change the temperature at the outlets.  If you want it a little bit warmer (e.g.dehumidifiing on a cool, foggy evening ), you're SOL.

 

IOW, you now have a cruder, less capable system.  IMHO, it's far better to rebuild your STV (if that was problem) and keep the original functionality than to replace it with inferior components.

 

NB: IIRC, the STV on the Riviera works differently from the STV used on other contemporary full-size Buicks. For those cars, higher vacuum at the valve lowers the evaporator pressure.  This is why the the Riviera AC can be such a PITA to fix; it has some unique parts.

Can the STV on the 63 be adjusted to bring 60 Lb of pressure on the low side down to 25/30 lb range?

Thank you

Red Riviera Bob

[Minimarvel]

Sorry to re-open this topic, but a little clear advice needed... 

I have a 65 Riv. Both Vacuum actuators on the A/C system where shot and had someone try to repair and re-seal them previously, thus I bought 2 of the 2 port units from "old air". 

All vacuum lines replaced and the whole system overhauled yet the doors still don't work well.. If at all. 

I found this thread which in part explains all but I am desperate for some clarification. 

The original vacuum actuators were 2 stage having 2 diaphapms inside and some form of check valve. The new ones are simply 2 port with a single diaphragm inside thus could you give me guidance on the correct "wiring" of the new ones. I understand they will now be either open or shut and not half open etc, so do I... 

Remove the vac tube that went to the outer connector of the original actuator and plug it.. 

Then take the vac tube that went to the center port of the original actuator, connect a "y" piece and connect both ends of this "y" to both ports of the new actuator. 

Many thanks guys... Fed up with the block of wood falling out... If you follow me..

[Turbinator]

5 hours ago, Minimarvel said:

Sorry to re-open this topic, but a little clear advice needed... 

I have a 65 Riv. Both Vacuum actuators on the A/C system where shot and had someone try to repair and re-seal them previously, thus I bought 2 of the 2 port units from "old air". 

All vacuum lines replaced and the whole system overhauled yet the doors still don't work well.. If at all. 

I found this thread which in part explains all but I am desperate for some clarification. 

The original vacuum actuators were 2 stage having 2 diaphapms inside and some form of check valve. The new ones are simply 2 port with a single diaphragm inside thus could you give me guidance on the correct "wiring" of the new ones. I understand they will now be either open or shut and not half open etc, so do I... 

Remove the vac tube that went to the outer connector of the original actuator and plug it.. 

Then take the vac tube that went to the center port of the original actuator, connect a "y" piece and connect both ends of this "y" to both ports of the new actuator. 

Many thanks guys... Fed up with the block of wood falling out... If you follow me..

The topic never closes. If you are a member of the ROA there is an article in the ROA tech section explaining how to do exactly what you want to do for a 63. I’m not sure how the 63 is the same or not for the same function on the 65. I can tell you mine works. I’ve done the single Vac actuator with two ports. I’ll take a pic of mine and send it. Are you using an STV or electronic switch to cycle the compressor? By the way there are a number of gents that read this forum who are quite knowledgeable on Riv AC.( I’m not one of them)

‘Turbinator 

[Minimarvel]

Thank you sir, 

Yes I am a member and indeed searched for this earlier... Maybe you might post a link. 

Not worried about the stv side of things as vac line blocked and stv modified to electronic with pressure switches in circuit etc. 

Only these damn actuators. The advice is to buy the expensive 2 port ones and then today I read that you feed both ports with one line.... Which makes me ask... Why not just use a simple $10 single port actuator in the first place? 

If we cannot buy a 2 "stage" actuator then what use is a 2 port one... 

You can see the confusion. 

Kindest Regards 

David 

[Minimarvel]

And I have searched again.... Any idea what section it's in... Or heading.....? 

Much thanking... 

[Turbinator]

1 hour ago, Minimarvel said:

And I have searched again.... Any idea what section it's in... Or heading.....? 

Much thanking... 

minimarvel, I’ll track it down and get you the info today. You have a 63 I thought you had a 65. Ive been jackin around with my AC. For 4 years. Last year is the first year I had AC. At the end of Labor Day all the R12 leaked out. I replaced everything NEW. I even had the hoses rebuilt! I’ve got way too

much spent on this AC. The system is specific to get started and an art to keep it running. My car is stock. If I had to do it over I’d bought an aftermarket AC and paid someone to put it in I’d be money ahead.

Bob

[Minimarvel]

No I definately have a 65...and know they are completely different, but the 2 port actuator is a 2 port actuator.... And not apparently a 2 stage actuator... But the rules must be the same. 

As said, I modified the Stv to an electronic switch.... Low coolant protection installed to protect the pump and a thermostat to control the temp in the car.... Just like a new Ford.... but all look stock, which is enough for me. 

Just don't quite understand why these pesky actuators don't work. 

There is not even any info on them anywhere... As said... If the fix is to feed both ports from one line, why bother having a 2 port valve.... Something doesn't make any sense. 

Greeting from a lovely spring England...

Regards

David 

 

[Turbinator]

5 hours ago, Minimarvel said:

Thank you sir, 

Yes I am a member and indeed searched for this earlier... Maybe you might post a link. 

Not worried about the stv side of things as vac line blocked and stv modified to electronic with pressure switches in circuit etc. 

Only these damn actuators. The advice is to buy the expensive 2 port ones and then today I read that you feed both ports with one line.... Which makes me ask... Why not just use a simple $10 single port actuator in the first place? 

If we cannot buy a 2 "stage" actuator then what use is a 2 port one... 

You can see the confusion. 

Kindest Regards 

David 

David, maybe at the time only the dual port actuator was available as I asked the same question. I have a new spare I’ll sell fairly as I have no use for it. I have to make sure it’s the right one and it holds a vacuum. If you have an extra now or readily available tomorrow buy that one no feelings hurt mate.

im sending a pic from the 63 service manual showing the dual port single hose ends up being feed to the “ small” port on Actuator one. Remember we are working on a design 55 plus years old and maybe not so good at the time it was new.

Nonetheless, old boy my actuators work. Right now I have a leak to run down in the AC. This is the best I can do today.

Bob Burnopp

( visited London once and held up at The Savoy Hotel. The Savoy is the most civilized hotel I’ve stayed in my life, a little pricey)

[KongaMan]

OAP makes a few "restoration" parts that don't work the same as the originals.  Caveat emptor.

[Jim Cannon]

The 2-port actuators are also 2-position units.

 

If you apply vacuum to the outer port only, the diaphragm will pull the actuator only 1/2 way in.  For the actuator on the plenum on the firewall under the hood, this will split output air half way between the dash vents and the floor heater vents.

 

If you apply vacuum to both ports, the actuator will retract fully. This will put all of the output air out the dash vents.

 

If you only apply vacuum to the inner port, you will find that it does not hold vacuum and the actuator does not move. You think the actuator is bad but it is not.

 

The double diaphragm mounted under the fan box controls air recirculation.  If the actuator is not retracted, you get 100% recirc of inside air into the heater-A/C. This is OK for A/C but you will fog up in the winter with the heat on like this. You need outside air.

 

If you apply vacuum to both ports under the fan box, you draw in 100% fresh air. Best for anything but maximum A/C.

 

If you do not connect a vacuum hose to a port, plug it with a golf tee.  You can't have a vacuum leak in the system or it will not work right.

 

I test all actuators with a hand held vacuum pump to troubleshoot.

 

 

[KongaMan]

That's the way they're supposed to work.  👍  If I understand his observation correctly, though, the OAP diaphragms don't work like that.  Rather, if vacuum is applied to either port, the actuator will retract fully.

[1965rivgs]

David,

  How do you know the 2 port diaphrams that are being sold are not 2 stage?

  What is the source of the $10 single port diaphrams you mentioned?

  It seems to me whether you are using the single or double nipple diaphrams either should function if all else is proper. As Jim suggested, isolate and test each component in the system independently. I have found that a non op component can be caused by a seemingly unrelated component bleeding just enough vacuum from the system overall to affect performance.

Tom Mooney

[Minimarvel]

Thanks guys for all your inputs.... But I am still none the wiser.... And this is the problem. I am an engineer so get completely how the system should work. Even gone one stage further by measuring the vacuum and setting it all up on a bench so to speak. My thoughts are that the new diaphragms are not the same as the original units because they only have a single diaphragm. Reading more... This apparently has been confirmed by the manufacturer at some point. 

What I really need is to hear from someone who has actually done it using the new actuator. 

The original is different also because there is a check valve internally. 

Single port actuators are available from many sources such as ebay and Alibaba... They are predominately used for waste gate usage on newer cars. 

If a single diaphragm with 2 ports is used without a check valve internally... The second port becomes the "leak" if you follow me under some settings. 

The selector switch on the 65 is not a tightly sealed unit thus it requires accumulative vacuum to work correctly, otherwise there will never be enough power to overcome the spring in the different doors of the system. But I am more than happy to be educated by someone who has actually done it. 

 

[Minimarvel]

If you read page 3 of this blog it explains the issue fully and mentions the "fix". 

Edited April 13, 2020 by Minimarvel
Found info... (see edit history)

[Minimarvel]

Ok found the thread. I think the confusion yet again is the reference between how they should work (with the original parts) and how to make the system work with the new 2 port ones... Which don't work in function or form like the original unit. 

The new units (I am guessing... But very near to tearing one apart) have a single diaphragm that can be actuated fully by applying vacuum to either port..... Which completely defeats the point of application and further creates the problem as without a check valve in some configuration of controls you have either fully open or fully open or nothing as in some positions this would create a massive vacuum leak. As has been said. The old ones are a 2 diaphragm 2 stage device... The new ones are a 2 port single diaphragm single action device.... That's the confirmation I really need as if so they can never work without modification to the circuit or system. 

[Minimarvel]

10 hours ago, Jim Cannon said:

The 2-port actuators are also 2-position units.

 

If you apply vacuum to the outer port only, the diaphragm will pull the actuator only 1/2 way in.  For the actuator on the plenum on the firewall under the hood, this will split output air half way between the dash vents and the floor heater vents.

 

If you apply vacuum to both ports, the actuator will retract fully. This will put all of the output air out the dash vents.

 

If you only apply vacuum to the inner port, you will find that it does not hold vacuum and the actuator does not move. You think the actuator is bad but it is not.

 

The double diaphragm mounted under the fan box controls air recirculation.  If the actuator is not retracted, you get 100% recirc of inside air into the heater-A/C. This is OK for A/C but you will fog up in the winter with the heat on like this. You need outside air.

 

If you apply vacuum to both ports under the fan box, you draw in 100% fresh air. Best for anything but maximum A/C.

 

If you do not connect a vacuum hose to a port, plug it with a golf tee.  You can't have a vacuum leak in the system or it will not work right.

 

I test all actuators with a hand held vacuum pump to troubleshoot.

 

 

 

[Minimarvel]

Thank you Jim.... But can you confirm... You are speaking about the original actuators or the new ones from old air parts? 

Thanks

Dave

[Turbinator]

14 hours ago, KongaMan said:

OAP makes a few "restoration" parts that don't work the same as the originals.  Caveat emptor.

Mr Kong’s Man, Old Air Products rebuilt my STV a couple of times. I had no luck and I can’t blame Old Air because of my ineptitude. Although my MAC lessons are expensive I am learning.

Old Air told me via telecom they rebuild vacuum actuators. I’m going to double check. I tried to rebuild vacuum actuator 3 and 4 on my 63. My rebuild would not hold a vacuum. I’ve looked at ASCO online for a vacuum actuator rebuild kit and had no luck. Although I had plenty of cool air last summer in my 63 the gas leaked out on Labor Day. I have the engine at the machinists for pistons,rings,etc. So, I’m revisiting the AC to fix the leak and thinking about possible changes/improvements for better cooling.

Since I’ve come this far I’m studying for EPA 608-609. It will be fun.

Turbinator

[Turbinator]

On 8/6/2017 at 2:21 PM, RivNut said:

 Old Air Products sells an STV (suction throttle valve) eliminator kit.  This replace the STV and incorporates a cycling compressor like modern systems. $165.  

Ed, so the STV ELIMINATOR  is different from the electronic cycling switch known as the STV update kit. How do the two methods differ in producing cold air?

Turbinator

[RivNut]

Turb,

 

I know less about A/C than I know about thermo nuclear warfare. (Kinda like automatic transmissions. They either work or they don't) Two kinds of people. Those who need work done and those who do it.  I am the former.

[Turbinator]

13 minutes ago, RivNut said:

Turb,

 

I know less about A/C than I know about thermo nuclear warfare. (Kinda like automatic transmissions. They either work or they don't) Two kinds of people. Those who need work done and those who do it.  I am the former.

Ed, is it work if you keep coming up short on desired result? Ha! Please trust me I'll be experienced on this AC stuff before it is over!

Turbinator

[Jim Cannon]

2 hours ago, Turbinator said:

Ed, so the STV ELIMINATOR  is different from the electronic cycling switch known as the STV update kit. How do the two methods differ in producing cold air?

Turbinator

 

They are basically the same but measure two different things to control the degree of cooling obtained.

 

One senses temperature on the outlet of the evaporator and cycles the compressor when the evaporator gets cold enough.  It turns the compressor back on when it gets warmer. 

 

The other senses suction pressure at the STV location and cycles the compressor when it gets low enough.  Then as the pressure goes back up, the switch turns the compressor back on.

 

[Jim Cannon]

7 hours ago, Minimarvel said:

Thank you Jim.... But can you confirm... You are speaking about the original actuators or the new ones from old air parts? 

Thanks

Dave

 

I am talking about original parts.  

 

For your reproduction actuators, I'd say you should plug the line that goes to the center port of the actuator and connect the line that goes to the outside port, with a T-fitting, to both the inner and outer ports of the new actuator. You will either get air out the dash or on the floor, never mixed (out both places) with this reproduction actuator.  If you want original function, get an original actuator.