I am getting ready to buy parts for my A/C and don't know where to start! I already have the suitcase (hope it's the right one), the evaporator, and the compressor.

I just ordered my heater core for a/c and now I'm a little lost. I know I need a POA valve and a condenser, but I hear talk of a Schrader valve(?) and other such parts. Can anyone steer me in the right direction as to what else I will need? Also, any links would be helpful and/or prices on the items I'll need.

Also, how am I going to get all of the A/C lines needed for the car? And when putting the suitcase together is there any type of special seals, or foam tubing that goes around lines coming from the suitcase?

I would love some pictures of A/C setups on-car, off-car, etc.

Thanks for the help as usual!

Mark D.

I have a 67 too, and the front end of mine is completely apart at the moment. I can take pictures of the various pieces and help you narrow down what is missing.

The main parts under the hood are:
compressor with clutch and pulley,
manifold/muffler assembly (bolts to the back/side of the compressor)
condenser (in front of the radiator)
receiver/drier (next to the condenser)
evaporator (fits in the suitcase)
TxV valve (connected to the evap)
POA valve (connected to the evap)
crank pulley for A/C
various hoses, brackets, and spacers

There are 2 schrader valves. One is part of the muffler assy (high pressure port) and one is on the POA valve (low pressure port). These are used to measure the pressure when the system is operating and to add refrigerant.

I can provide links to some of the parts that are available. Some are available through parts houses, some are on eBay. Some parts are very hard find.

Do you have the ducting for the interior?

Pete

Something else with a lot of information - go to the Library on Vikki's First Gen Site and get the 1B Custom Air Conditioner section of the 1967 Firebird Manual Supplement. Link to Custom Air Conditioner pdf. It has a lot of detail on the A/C components, wiring, interior controls and ducting.

Pete

Thanks Pete! Are you getting ready to put your A/C back in soon? If so any pictures would be of a great assistance.

I do have the duct work except for the bottom center portion that comes below the ashtray (I think that is what it is).

Any pictures on how the duct work is set up? I was curious about that also.

Thank you so much for all the help and information! It is really going to help me out when it comes time to put everything together properly.

Realistically, I'm probably about a year away from getting my car together again. With the car apart, I can get good shots of the parts and brackets for you. When assembled, the engine bay is so crowded it is hard to get good shots of everything. I do have some pictures that I've pulled off the internet. They may even be from FGF members cars. Here are two to get started.

You can see the compressor with the manifold/muffler attached to it. You can see the POA valve on top of the suitcase. The U shaped tube from the POA valve into the suitcase is part of the evaporator. the U shaped tube from the POA valve toward the back near the firewall is a separate piece you will need to get.

There are 4 brackets used to attach the compressor to the engine. You can see two of them here. The large bare aluminum bracket bolts to the front of the compressor and to the front of the block. There are two large spacers between the bracket and the block where the slotted holes are. There is also a V shaped bracket from the back of the compressor to the intake manifold. Again, there are two spacers, one between the bracket and compressor and one between the rear bracket arm and the intake manifold. One caution about the V bracket - there was a subtle change to the shape around 1970 or so, subtle enough that it is hard to tell the two styles apart. If you have a later intake manifold you will need the later bracket. I can get pictures showing the difference in the intake manifold mounting points.

As I said in the previous post, there are 4 brackets attaching the compressor to the engine. Here are pictures and drawings detailing them.

I think the long thin bracket just below the V bracket was only used for the 69 year. It is a brace from the lower rear of the compressor to the cylinder head. I'm not sure that 67s and 68s had that bracket.

These brackets can be found on eBay from time to time. They are listed now. Or another listing.

Another seller, MotorCityMuscleCar on eBay sells bolt and spacer kits to mount the brackets. This is a link to the complete kit.

There is also a guy ThePartGuy that has many Pontiac / Firebird A/C parts. He sells from the website and on eBay. His stock varies so you will need to check back from time to time.

Pete

Awesome info/links, Pete!

I have always wondered how the duct work gets to the vent balls? Is there some kind of flexible plastic tubing that extends from the duct work to the vent balls? I have never seen anything for sale or available for this purpose.

Also, is there a seal for the suitcase that is sold, can silicone be used, or is there no seal at all?

I have also seen some pics of some kind of foam wrap that goes on some of the hard lines coming from the evaporator on some cars. What is this if you happen to know?

Keep the info and pics coming! Any more info would be appreciated as this is helping me out more than you can imagine!

Thanks again for going to all the trouble, Pete!

Mark D.

Mark, thanks for the thumbs up! I'd like to use this thread to document the entire A/C system as best I can and cover all the components, ducting, controls, baffles/filler panels, wiring, etc. Hopefully, it will become "the ultimate A/C thread". It may take a while to post it all and it will have a slant toward 67s. 68s are pretty similar and 69s have some extra vacuum controls that I'm not as familiar with.

My thought was to cover in the order of: the compressor and brackets, condenser, receiver/drier, evaporator and suitcase, expansion valve (TxV) and POA, interior ducting, controls and vacuum lines, and wiring.
I'll try to answer any questions as they come up so I don't loose track of them.

There are 2 outlets on the interior ducting that connect to the vent balls with flexible hose. I'll post pictures when I get to the interior ducting. Many parts houses sell a 3" hose as correct for firebirds, but the right size is 2 3/4". Ames Performance sells the right hose as part number FP562DM.

Rick's Camaro sells a 3-piece evaporator case half seal set. Part #AC-51 I haven't bought it, so I'm not sure what it is made of. I was planning on using 3M Strip-Calk to seal the case halves and the case to the firewall. There is also 2 seals where the evaporator tubes exit the suitcase. Rick's sells this as part #AC-53

The foam wrap is used to wrap and insulate a sensor coil on the expansion valve to the upper evaporator tube. More pics of this when I cover the evaporator. Ricks sells it as Part #RC-206. Ames has it for less as part #FP321TK.

Disclaimer - I'm posting links to parts as examples only, and not meant to be the best deal. Do your homework and shop around the various parts places.
Pete

A comment on the previous drawings that show the mounting of the black painted cast iron bracket. The drawings show the bracket being mounted with bolts to 2 cast tabs on the cylinder head. In reality the bracket mounts using the cylinder head bolts. I haven't removed the bolts to verify, but I think they must be longer than the other cylinder head bolts to account for the thickness of the bracket. The front-most one has a threaded stud on the end that the battery ground cable attaches to.

Also note that the A/C cars have a long upper dipstick tube that curves over the valve cover. It goes between the valve cover and the compressor when the compressor is in place. The one in the picture has a tab in the wrong location. The tab should be lower down on the tube and attaches to the front valve cover bolt.

Pete

If you need information on pulleys, look at the Illustrated Parts Index 1973 on Vikki's site and click on the Pulleys and Belts link. Scroll to the diagram that matches your engine (6 or 8 cyl) and accessories.

I have a 67 8 cylinder with A/C and power steering. According to the diagram, the crank pulley is #22, an 8", 3 groove pulley. My car actually has the setup listed for a '68 cyl with A/C and power steering. Also listed as #22, it shows a single 7 5/16" pulley for the A/C and an 8" 2 groove pulley for the other accessories. I don't know if mine has been changed, or what. There is a thick rubber ring that fits between the single and double pulley, presumably to dampen vibrations.

Pete

Pete, the wealth of information you are posting is truly amazing! This will help me so much, as well as others, in the search for the A/C parts needed to complete this daunting part of the rebuild. Keep documenting and I'll keep reading!

Thanks again so much!

Mark

I mentioned earlier that there were 2 versions of the bracket from the compressor to the intake manifold. This High Performance Pontiac Article compares different intake manifolds. Photo 11 shows the 2 brackets together. Starting in 73, the front mounting boss on the intake manifold was moved outward and the front arm of the bracket was shortened. If you are using a later intake or an aftermarket intake, you might need the later upper bracket.

Here are some pictures of an early style bracket. The first one shows the bracket next to a 67 intake manifold. The bracket holes align with the bosses. The second picture shows the bracket next to a Edelbrock Performer intake. You can see the front mounting boss has been moved toward the edge of the manifold.

Pete

Early bracket and 67 intake


Early bracket and Edelbrock Performer intake

Firebirds used the A6 compressor. The manifold/muffler assembly bolts to the back of the compressor and is also held by a bracket at the front. The port on the left (closest to the engine) is the input, coming from the POA valve. The outlet feeds into the muffler and then on to the condenser. There is an overpressure relief vent at the back of the compressor, and the high pressure port (schraeder valve) on the back of the muffler. At the front is the pulley and the electric clutch.

The bulge on the bottom of the compressor in the second picture is the oil sump and the bolt is a drain plug. This should not be opened if there is still refrigerent in the system.

The third picture shows the pivot bracket part number is 9789228.

The fourth picture shows the original label on the compressor. Firebirds took 3.75 lbs of R12.

The output of the compressor muffler goes to the condenser and receiver/drier at the front of the car. The condenser mounts to the front of the core support. There are 2 mounting brackets that are bolted to the condenser and then the brackets bolt to the core support. I think 69s use a different condenser and brackets than the 67-68 setup.

If you are converting to R134a and are not concerned with originality, you may want to consider getting a modern parallel flow condenser. Parallel flow condensers are more efficient and the system will work better when using R134a, but will probably need some mounting bracket and hose connection fabrication.

Pictures 1 and 2 show the driver's side condenser mount.

Pictures 3, 4, and 5 show the passenger side mount. In picture 3 the bracket is partly hidden behind the hose between the condenser and the receiver/drier. Picture 5 is a close up of the bracket to condenser mounting using a U-clip.

Driver's condenser mount


Driver's condenser mount


Passenger side condenser mount


Passenger side condenser mount and receiver/drier mounting bracket


Close up of condenser mount U-clip

67s have a different receiver/drier and mounting bracket than 68-69s. The 67 receiver/drier is short/fat and mounts next to the condenser. In 68-69 the receiver/drier is taller and narrower and was moved to the passenger fender well.

If the system has been open or discharged for any length of time, the receiver/drier must be replaced. There is a desiccant bag inside that absorbs moisture. If open to the air, the desiccant will be come saturated. New receiver/driers do not look the same as the original GM units. If originality counts, there are some A/C shops that can cut open your original, replace the desiccant bag and weld it back up.

Note - I read in these threads AC Hose Clamps and Sealing Barrier Hose with Clamps on the Automotive AC Information forum http://www.autoacforum.com/ that the barbed hose fittings and worm drive hose clamps can leak if using the newer barrier hose (for R134a). There is a nylon liner inside the barrier hose that is not as compliant and does not seal as easily as the older style hose. I have not gotten my A/C running, so I haven't tried any of the proposed solutions in the threads.

In picture 1, you can see part of the rubber filler piece "masticated filler" that helps seal off the gap between the bumper bracket and the core support.

Picture 2 shows the receiver/drier and its mounting bracket.

Picture 3 shows the receiver drier and hoses from a different angle. The hose on the lower left comes from the compressor muffler and the hose on the upper left goes to the expansion valve at the evaporator. There is a foam sleeve over the lower hose to protect it from rubbing against the bumper bracket.

Pictures 4 and 5 show how the hoses are routed from the core support around to the engine bay. The lower hose is wedged against the bumper bracket and core support and the foam sleeve protects it.

Pete

Receiver/drier and rubber filler


Receiver/drier and mounting bracket


Receiver/drier and hoses


Hose with foam sleeve


Hose routing to engine bay

Here is an "overview" shot. I probably should have taken this pic and posted it earlier to give a big picture of the system.

I lined the components up as they are located in the car. The condenser would be in front of the core support. The compressor would be mounted to the engine, and the evaporator would be inside the suitcase on the firewall.

Also attached to the evaporator is the expansion valve (with the small coiled lines) at the front/center, and the POA valve at the top.

The output line at the bottom of the compressor muffler would connect to the hose that is laid next to it. This is the hose that connects to the condenser. The other hose, coming back from the receiver/drier has a hard line crimped to it (see the second picture for a close up). The hard line goes into the expansion valve. The output of the expansion valve screws into the evaporator inlet (the tube going to the bottom of the evaporator). The evaporator outlet tube, at the top, goes to the POA valve. The shiny U-shaped tube at the POA outlet would connect to a hose going back to the manifold inlet. In the picture, this hose is missing and the barbed end of the manifold inlet tube is broken off.

Pete

Here are details of the evaporator, expansion valve, and POA valve interconnections. The expansion valve inlet (threaded side connection) comes from the receiver/drier. The expansion valve main body outlet on the bottom is attached to the lower evaporator line. The small line coming out of the side of the expansion valve is called the equalizer line, and it connects to a port on the side of the POA valve. There is also a small tube coming from the bottom rear of the evaporator that connects to another port on the POA valve. This is the liquid bleed line.

If you are buying a used POA valve, be aware that some valves may have the ports located at different points on the side of the valve, depending on what make/model car it came from originally. I think there are 3 or 4 different "clocking" configurations.

Thermostatic Expansion Valve


Expansion valve and equalizer line to POA valve


POA valve connections


Evaporator liquid bleed line to POA valve

The POA valve is mounted to a bracket on the suitcase with a clamp on each end of the valve.

The small capillary tube coming out of the top of the expansion valve has a coiled end, called a sensing bulb. The sensing bulb is clamped to the evaporator outlet, called the suction line. The sensing bulb monitors the temperature of the suction line and must be in close contact in order to read the temperature properly. The sensing bulb should be positioned on the side of the suction line, not the top or bottom. (Not sure why, but I read that, and that is how mine was clamped.) The last picture shows black insulation tape wrapped around the suction bulb to insulate the bulb from the ambient air temperature.

If you are converting your A/C to use R134a, the POA valve should be recalibrated to lower the evaporator pressure from the 30 lbs used by R12 down to approximately 27 lbs that works best for R134a. There is an adjustment screw inside the POA valve, accessible from the end. Turning the screw 1/2 turn counterclockwise will lower the pressure setting. If you have a gauge set, you can connect the low pressure gauge to the port on the POA valve, feed 60 PSI air into the inlet and adjust the POA pressure set point.

Pete

POA valve mounting clamps and suction line bulb


Suction bulb clamps


Suction bulb insulation

Here are pictures of the suitcase, evaporator, and blower motor. The first picture shows the two halves of the bare suitcase. Note that the inner half has a large hole in it. This happened due to a combination of deteriorating subframe bushings, and dropping the rear of the transmission/engine in an attempt to fix a transmission dipstick tube leak. The passenger valve cover hit the suitcase and broke out a large chunk.

The second picture shows the inside of the suitcase with the blower motor/impeller and evaporator in place. The third picture shows how the evaporator is held in place between the 2 halves of the suitcase. There is a gasket on the outer suitcase (fourth picture) and a metal baffle to seal the outer half from the inner half and force all airflow through the evaporator. The evaporator upper tube foam seal can be seen in the lower left of the fourth picture.

The fifth picture shows the inside of the inner suitcase half.

There are part numbers molded into the halves of my 67 suitcase:
Outer half = HRD P/N 3013465
Inner half = HRD P/N 3013466

Pete

Suitcase Halves


Suitcase Inside


Suitcase and Evaporator


Evaporator Gasket


Suitcase Inner Half

A/C cars have a more powerful blower motor than the non A/C cars. There is a cooling tube that feeds a small amount of the blower air back through the motor to help cool it. The first 2 pictures show the cooling tube pieces.

The suitcase is mounted to the firewall using a combination of screws and studs. The third pic shows a stud that screws into a hole above the blower opening. This stud had a big gob of sealant around it on both sides of the firewall. There are also 2 studs attached to the heater core box on the inside of the firewall. They poke through the firewall and secure the inside edge of the inner suitcase. These 2 studs are visible on the right side of the fourth pic.

As you can see in the last 2 pictures, it might be a good idea to remove the suitcase for cleaning if you ever get a chance. The evaporator can get plugged with leaves and other debris sucked in through the cowl. In my car, a mouse had created a large nest in the suitcase using batting from the seats.

Pete

Blower Motor Cooling Tube


Cooling Tube Pieces


Suitcase Mounting Stud


Heater Core Box Studs and Mouse Nest

I think once you guys get your cars back together, this thread needs to go into the hall of fame for the good documentation!

Here are some pictures of the heater core case that is inside the car under the passenger side dash. There is a foam rubber seal around the edge of the case to seal it to the firewall. There is also a dense foam seal that goes over the heater core tubes. I haven't been able to find reproductions of these seals anywhere.

The inlet tube is the smaller of the two heater core tubes. The factory inlet tube is crimped down at the open end. This is to restrict the flow somewhat and to prevent a high pressure surge from blowing out the core when the engine is revved.

There are three mounting studs on the heater box that go through the firewall - one next to the heater core inlet tube, and two on the opposite side of the heater box.

Inside the heater case are some air control flaps and plastic diverter pieces. The larger flaps have a rubber seal at their outer edges. The 2 small flaps have a thin (1/8" or so) layer of foam glued to them. In the pictures, the foam is crumbling and has partially fallen off.

Heater cores for A/C cars are different than the non A/C version. The A/C core is 2.5 inches thick. Some vendors sell a core that is only about 2" thick (a Camaro version?) and is too small for the mounting brackets.

Pete

I forgot - I wanted to include a picture of the heater core and one of the hold down brackets.

Pete, you have gone above and beyond the call of duty and I must salute you! I cannot believe the amount of valuable information you are supplying. Every day it is something new it seems!

I do have a question. Does the box that houses the heater core fit up against the firewall insulation pad, or is it cut out around the box for the seal to properly seat against the metal of the firewall?

Keep the info rollin'!

Thanks again,
Mark

.. Another case of Minnesota nice!

One thing I know for sure, when I dive into getting my AC working, this thread will be a lifesaver. A future thank you.

Thanks for the props and encouragement! (What's the Minnesota expression for "Aw, shucks"?)

Since I got my bird 7 years ago with the A/C disconnected and some pieces missing, I've been researching and reading to find out what I have and what parts are missing. Now that I have the car apart to fix a bunch of stuff, it is time to finally collect the remaining pieces so I can get the A/C working again. Since the car is apart, it is much easier to document the system.

Mark - excellent question about the firewall pad! I wondered about that too when I took my heater box off, removed the firewall insulation, and was looking to buy a replacement firewall pad. My pad stops just short of the heater box, but the replacements I see cover the whole firewall.

I don't think anyone had ever had the heater box off of my car before so I think my pad is untouched, but I can't be sure. The pad stops just before the heater box and the right edge looks relatively crisp, straight, and "factory" so I don't think there was a section behind the heater box that fell off or was torn off. Also, there is the thick rubber gasket that goes around the outer edge of the heater box. It makes sense to me that the rubber gasket would seal against the firewall metal. Maybe the replacement pads extend behind the heater box and can act as gasket in case the original rubber gasket is too far gone? It would also add a bit more heat and noise insulation.

Here is a picture of my original pad next to a replacement pad. I still haven't decided whether I will install the whole pad, or if I will cut it at the heater box.

I ended up returning this pad (the Ames more expensive molded one). Even though it was advertised as for 67-69, the fuse block shape is different for 67s and 68-69. The 67 fuse blocks are tall rectangular shape with mounting screws at the upper left and lower right. 68-69 fuse blocks are more square with mounting screws at upper right and lower left. It just wouldn't work for me. Some brands of pads are cut for 67s, some are cut for 68-69, and some are scored for both and you remove the cutout shape you need for your car.

I ended up buying an unmolded "Re-pops" brand with the correct cutout for my 67.

Pete

Original Firewall Pad


Old and new pads


Fuse block different shapes

Here are the pieces that make up the air duct distribution system under the dash. This is for a 67. 68 and 69 are slightly different in some areas. The Air Conditioning section of the 1973 Illustrated Parts Index has a good diagram showing all the parts and differences from year to year.

In the first pic, from top to bottom:

.......................Defroster Duct (Y shaped piece)

....Defroster End Duct -- Defroster Distributor -- Heater Case

Left Dash Outlet -- Lower Center Outlet -- Main Duct -- Right Dash Outlet

.................Left Hand Outlet Duct -- Center Dash Distribution Duct

....................Center Dash Outlet with chromed deflector

The second picture shows the Lower Center Outlet attached to the bottom of the Defroster Distributor. The Lower Center Outlet pushes into a clip at the back of the Defroster Distributor (at the bottom in the picture) and is held at the front with 2 screws. The Illustrated Parts Index shows a different part number for the Defroster Distributor for each year, with 69s having a vacuum actuator.

Picture 3 shows the Defroster Distributor and Lower Center Outlet attached to the left side of the Heater Case.

Picture 4 - The Y-shaped Defroster Duct is mounted to the inside firewall. When the Heater Case and Defroster Distributor are in place in the car, the louvered opening on the top of the Defroster Distributor lines up with the bottom of the Defroster Duct. The gap is exaggerated in the picture. The Camaro heater seal kits come with a foam gasket to seal the Defroster Duct to the Distributor, and 2 seals that go between the defroster outlets and the underside of the dash. The Firebird parts manuals don't show these seals.

Picture 5 - The Defroster End Duct is attached to the left side of the Defroster Distributor. The outlet of this duct points down toward the driver's footwell. The Illustrated Parts Index shows the Defroster End Duct as a 67 only part.

Ducting Parts


Defroster Distributor and Lower Center Outlet


Defroster Distributor and Lower Center Outlet attached to the Heater Case


Defroster Distributor and Defroster Duct


Defroster End Duct on Defroster Distributor

The first picture shows the Main Duct attached to the opening at the front of the Heater Case. It slides into a clip at the top of the Heater Case and 2 screws hold it at the bottom. The Illustrated Parts Index shows a gasket between the Main Duct and the Heater Case, but the Camaro heater seal kit does not have this gasket.

Second picture - The Left Hand Outlet Duct slips over the round outlet on the left side of the Main Duct. The Left Hand Outlet Duct fits into the curve of the Lower Center Duct and a screw attaches it to the Defroster Distributor. A piece of 2 3/4" diameter flexible hose attaches to the outlet of the Left Hand Outlet Duct and goes to the Left Hand Dash Outlet. Another piece of 2 3/4" hose connects from the round outlet on the right side of the Main Duct and goes to the Right Hand Dash Outlet. When everything is in the car, the right side hose sits on top of the heater case and goes behind the glove box insert. A/C cars have a different glove box that is not as deep in order to make room for the hose.

Third Picture - The Center Dash Distribution Duct slips over the oval outlet at the upper front of the Main Duct and goes to the Center Dash Outlet. The Center Dash Outlet is different for 69s.

I can't find a source to verify it, but I have a thought in my head that the A/C cars used a slimmer radio dash speaker so as not to hit the Center Dash outlet. Many aftermarket dash speakers are larger and won't fit in A/C cars because the Center Dash Outlet is in the way. Maybe that is what I'm thinking of.

Fourth Picture - The various duct pieces are held together with #10-16 x 5/8" screws. While any #10-16 screw would work, the factory used a screw with "tall" hex head. I found these screws at Ricks Camaros - part #HW-96 "BB Heater Box Flange Plate Screws". They're a bit expensive at $3/pair, but not too bad if you are only missing one or two.

Pete

Main Duct on Heater Case


Main Duct with Left Hand Outlet Duct


Center Dash Outlet and Distribution Duct


Heater Duct Screw

Here are pictures and a description of operation of the control assembly and cables.

Picture 1:
The top-most lever controls the mode and temperature:
OFF - Outside air, compressor off, blower off
VENT - Outside air, compressor off, low speed blower
COLD - (Above and slightly left of COLD) Recirculated air, compressor on, low speed blower
COLD - (Above and slightly right of COLD) Outside air, compressor on, low speed blower

As the temperature lever is moved from COLD towards HOT, some air is sent through the heater core. Midway between COLD and HOT, the compressor turns off.

HOT - Outside air, all directed through the heater core.

Although the service manual states that the blower will be on low speed in any position other than OFF, my control assembly does not have the blower switch to activate the low speed mode. The blower is completely controlled with the FAN switch.

The middle lever controls the outlets:
UPPER - All air is directed to the dash outlets (center outlet and left and right ball outlets)
LOWER - All air is directed to the heater outlets (lower outlets and defroster outlets)

The lower lever controls the defroster outlet:
OFF - All air is directed to the lower outlets
DEFROSTER - Air is divided between the lower outlets and the defroster outlets
DE-ICE - All air is directed to the defroster outlets.


Picture 2 shows the levers and control cables from the underside of the control assembly.


Picture 3 show the control assembly and cables connected to the heater case and ducting.
The upper (temperature) cable is 44 1/2 inches long and connects to the temperature door arm at the right/rear corner of the heater case. The temperature cable is also attached with a clip at the left end of the defroster distributor.
The middle (diverter/outlets) cable is 36 inches long and connects to the diverter door arm at the front/center of the heater case.
The lower (defroster) cable is 29 inches long and connects to the defroster door arm at the back of the defroster distributor.


Picture 4 is a close-up of the defroster cable, taken from the back.


Picture 5 is a close-up of the diverter outlet cable (on the left) and temperature cable (on the right). Note that each of these cable mounting brackets have slotted holes so that the cable position can be adjusted. I adjusted mine so that the doors just reaches the end of their travel when the associated lever is in the left-most (OFF or UPPER) position. Also note that each cable end should have a round cable retaining nut to keep each cable on its arm, as is shown in picture 2.

Pete

Control Assembly


Control Cables


Cable Routing


Defroster Cable and Defroster Door Arm


Diverter and Temperature Cables

Fresh air / recirculated air doors

A/C cars have a slot in the cowl which holds the cowl fresh air vent door. There is also a small bracket on the back of the cowl / upper firewall area.

The cowl vent door assembly drops down into the slot and is held down with 5 screws and a healthy dose of seam sealer. There are strips of foam on the front and back edges of the vent door assembly which seal against the front of the cowl, and against the side of the bracket on the back of the cowl.

With no vacuum applied, the vent door is held in the horizontal or open position by a spring. When vacuum is applied to the actuator, the door is pulled closed and blocks the fresh air inlet to the blower.

Picture 1 - The passenger kick panel holds the recirculated air door and actuator. A spring holds the door closed when no vacuum is applied to the actuator. (Note that the spring in the picture is a generic spring from a hardware store. )

The default vent mode uses outside air with the cowl vent open and the kick panel vent closed. When the temperature control lever is above and slightly left of the COLD position (recirculated air conditioning mode), vacuum is applied to both the cowl and kick panel vacuum actuators, closing the cowl fresh air door and opening the kick panel recirculation door. (More on vacuum lines and operation coming soon.)

Picture 2 - The back side of the kick panel has a small piece of jute padding glued to it and a large amount of putty/sealer to seal the panel to the car.

Picture 3 - The kick panel and actuator in place.

Picture 4 - The actuator cover in place. Please ignore the mis-matched and missing screws.

Pete

The fresh/recirculated air doors and compressor switch are activated by vacuum. The vacuum is supplied by the engine. A vacuum tank is mounted to the driver's firewall under the fender. The tank is a vacuum reservoir and maintains a high vacuum level to operate the A/C system when the engine is under heavy load and engine vacuum drops. The larger vacuum port connects to the engine vacuum source. This port has a check valve so that the vacuum in the tank is maintained when the engine is off.

The vacuum tank outlet line goes through the firewall through a hole located just above the steering column. A hard plastic grommet protects the line where it goes through the firewall.

All of the factory documentation I have seen just describes the source vacuum line as connecting to the engine vacuum source with no other detail of exactly where the line connects. Mine was disconnected long ago, so I don't have a good reference here. I imagine the engine vacuum connection point is different depending on the engine/carburetor combination.

IF YOU CAN HELP - It would be nice if owners of A/C equipped cars could post what engine/carb combo they have and what is used as the engine vacuum source for the A/C system. (Thanks in advance!)

Pete

Vacuum Tank


Vacuum line under dash


Vacuum line grommet

Picture 1 - A vacuum control valve is linked to the upper control lever and routes vacuum to the fresh/recirculated air doors and the compressor switch depending on the mode selected.

Picture 2 - While you could connect each vacuum line directly to the ports on the vacuum control valve, the factory used a rubber harness connector. It has 3 short sections of steel tubing pressed into holes in the body of the connector and the vacuum lines connect to these steel tubes. the other side of the connector fits over the ports on the vacuum control switch. Using the harness connector makes it harder to mix up the vacuum lines and there is a rubber tab that was glued to the top of the valve to keep the connector from coming off.

Picture 3 - The vacuum control valve
Port 1 (at the rear) connects to the vacuum tank.
Port 2 (middle) connects to the compressor switch (the switch with the black diaphram at the back of the control assembly).
Port 3 (toward the front) connects to the fresh/recirculated air door actuators.

Picture 4 shows the routing of the vacuum line to the fresh/recirculated air door actuators. The inset picture shows a Tee connector (on edge and hard to make out). The line coming off the center of the Tee goes straight forward and out another grommet through the upper firewall and goes to the fresh air door actuator.

Picture 5 - The vacuum line going to the fresh air door actuator. A large blob of sealer seals it to the firewall.

The '69 cars have a more complex vacuum system, including an additional vacuum control at the defroster distributor and a vacuum controlled heater core shutoff valve.

Pete

Control valve and vacuum lines


Vacuum hose harness connector


Vacuum control valve ports


Vacuum line routing


Fresh air vent door vacuum line

You are correct on the bolt length being longer. I couldn't remember removing this bracket when I removed the head bolts. I couldn't figure out why I had two bolts that were about an inch too long! It just didn't make sense that the factory would design a bracket that goes under a head bolt, IMO. I figured it out with the help of you guys.

Also, I put the studded bolt in the second postion, but this puts the dipstick in the way of screwing on the nut that holds the battery cable. Is this pic an original? I think it makes more sense to put the stud in the front position like yours.

Larry

Awesome doc & pics. I captured it all into a pdf file should anyone want to download it.
pdf file of thread

The link isn't working for me.

The pictures in the post that you quoted are of my engine. They show the stud in the front position, but I'm pretty sure a previous owner took the heads off, so I'm not sure that they put the stud back in the original spot or not. If the dipstick tube interferes with the stud in the second position, maybe the front position is the way to go.

I found another picture of a different car that also shows the stud in the front spot, but again, I don't know if it is original.

Pete

Thanks for bumping this. I need to get off my butt and finish it. I still want to post some info on the electrical wiring, and something on the A/C baffles and radiator rubber filler pieces. Is there anything else missing that would be good to put in here?

Thanks,
Pete

Hi Pete, I have factory A/C now and it's a mess. First thing I need to do is cleanup the wiring. I have not found a decent wiring diagram for the heater controls from interior to the engine area. Do you have any?

If it would help, I have this '68 Firebird AC diagram with the vacuum lines and wiring. Let me know if you want a better resolution one. This does not come out well crushed down.

I only have the same diagrams as Jim posted. I know the A/C wiring changed over the years so I don't think my 67 wiring would be a match for your 68.

Pete

Look in the 1967 Supplemental manual for the Firebird. Its on Vikki's site.

The wiring was fried at the suitcase. Bypassed the unit and went direct to the fan. Just needed fan to prove I could run defrost for the inspection.

Is the 67' A/C system pretty close to the 68' configuration?

Anyone rebuilt their compressor before?

Never heard of anyone rebuilding their own compressor bu I am sure someone has done this. WRT the wiring diagrams, both the 67 and 68 are available on Vicki's site. They are similar but not exact. The 68 is in the wiring diagrams, the 67 is in the Supplemental manual.

I mean has someone done it themselves or had it done for them.
For starters I want to confirm the parts so I will check out Vicki's site.

how is this post not in the hall of fame. a/c cars are few, but out there. this is the largest gathering of info I have seen, and with pics . I found it looking for a/c core shield pics on the third page of google, so please to the powers that be, save it, and make it easier to find. thanks

The search feature Geoff put together works really well (I assume you did it Geoff). If you open up the dates and play with both the title and body you will find a huge amount of info out there over the past 10+ years. Also play around with the quotation marks. Unlike Google where you get 100,000 hits of garbage most of which have nothing to do with FGFs.

Hello all, I also have a 67 Firebird with A/C, and I have a question as well, what I am in need of is where the vacuum source is for the Vacuum Canister on the Firewall, behind the Left Fender? I have figured out all the other Vacuum Lines, have everything ready, but do not know where the original vacuum source hook up is on the engine for the Canister, my car is a Convertible 400cid, 400THM, NON Power Brake car, I have a Carb bolt that has a vacuum port on it that I assume is for manifold vacuum, I have the port on the front right side of the Carb for the Vacuum Modulator on the Trans, and I have one last port on the front bottom left side of the Carb that I assume is for my Distributor Advance, the port at the base of the Carb that would be for the Power Brakes? has a plug in it. The A/C Vacuum line to the Canister was removed before I owned the Car, and I have just finished redoing all my A/C stuff and looking for the final piece to the puzzle on it, I am not sure if the Carb Bolt Vacuum Port is for the Canister, or if I have to put some sort of screw in port in the base of the Carb for the Canister. If anyone has any Idea of where it should go, that would be great. Thanks for your time.

I posted a general discussion on this but got no replies. I really could use some opinions from firebird owners. I am reconditioning my 69 firebird that has factory AC. I took the compressor and brackets out 20 years ago (kept all parts but hoses leaked) and parked the car a few years later. I finally got around to working on it and am having the 350 engine rebuilt, better cam, lifters, rockers, valves, pistons, ignition and adding 4 bbl. Trying to keep it as original as possible. Now...I have many friends telling me to put in vintage air or some other after market type. Newer, more dependable etc. But I hate to spend $1500 when I have all the original parts. Aren't the original good enough and upgradeable enough to serve my purpose? I'm not looking to sell the car, leave it to my son and grandson, so value isn't my motive. Really could use advice from you Firebird folks mot just on the AC but everything in general when ? restoring, reconditioning?. Appreciate any opinions. Thanks, Tork

I have never owned a classic car with A/C, but if it were me, I'd ALWAYS vote for stock over aftermarket.

Thank you for your response! Over the next summer I'll probably be relying a lot from input from members about my car. The information I've seen posted by Pete67400 (another Minnesotan) about the AC system is unbelievable, what a wealth of knowledge he has! As I get into this hopefully I'll find out what components of the system will need to be replaced, both for upgrading to the R134A or due to the years of exposure to the air with the hoses off. So anyone reading this, please help if you can. I read that there is a good possibility of mouse nests in the suitcase, especially since mine sat covered outside for years, so I'll need to figure out how to disassemble that and check it. But anyway, thank you again and I'll be appreciative of any help I get!

Mine has stock A/C and I'm rebuilding it. Thing I dislike about the aftermarket A/C is they do not bring in fresh air. 100% recycled ... yuck! Stock does...

Thanks Gus68, full disclosure...snowbirding too. Gathering info for my wrenching return to northern MN from AZ in April (if ice is off). Didn't know that about no fresh air, very good reason to keep original too!

Where in MN are you?

Detroit Lakes area.

Ah, you won't need A/C way up there... Just mosquito netting...

I have factory AC in mine as well (though it's not completely finished yet.)
I plan to replace the compressor (and hoses) with a newer unit, but the rest of the system is stock.

Thank you! I get confused, at a car show yesterday, a firebird guy said that he thought when you upgrade to R134a, you need to replace your evaporator and the valve. Another said you can get better efficiency if you replace the compressor also with a more modern one. I'm sure someone out there has actually done theirs. Like to hear from you.

I have done quite a few of these systems from using all factory parts A6 compressor...etc to vintage air. If you don't care about originality vintage air is the way to go if you want ultimate cooling. The factory ducting is not quite that efficient with cooling. But mind you this is where it gets to 116 out here in AZ. It may be fine in other parts of the country where the outside Temps don't get as high.
It also helps to have a bigger condenser when switching to R134 and all the baffles up in front of the car.
Last bird I did was a 67 with an aftermarket under the dash unit with the sanden compressor and R134. It cools good enough when it's above 90 degrees here.

What an awesome and informative thread. I'm installing an original A/C system in my 67 that came with factory a/c. I had some original parts, but had to piece together almost everything. That would have been enormously difficult without this thread, so many thanks to everyone who contributed.

I have a question, does anyone know if the compressor label on page 2 is reproduced? My original label is identical to that one and I can't find one anywhere.

Once again, thanks for this priceless library of information!

We were able to find a replacement compressor. I am not sure about the decal and I do not have the car to check.
I believe that we got it from Global Parts? I will check that name for you.
Cal

Edit - Global Parts Distributers
http://www.globalpartsdist.com/catalog/

Thanks for the response Cal. I actually had the original compressor and decided to re-seal it myself. The internals were almost new as it was removed sometime in the late seventies (I know the history of this car since 1969).
So it's all done & painted and ready to go, but I was looking for the correct decal.
If I did it right, there should be a picture of the original decal currently on the compressor, which I painted around.
By the way, if you search on YouTube, you can find the tips needed to do a rebuild on your own, if you have the few tools required.
Thanks again,
Sam

Original A/C Compressor Decal

Has anyone ever replaced the evaporator box seal that seal the 2 suitcase halves? I need all the seals and gaskets that go inside the box and can only locate the 2 that fit around the tubes. Any help would be appreciated.

I looked for these as well and was unsuccessful. I reused the evaporator to case seal as it's heavy and was in good condition. For all other seals, there's a vendor that sells a sheet of 3mm thick dense foam material on e bay, that's 17" wide and sold by the foot. I cut my own gaskets and attached them to one side of all mating surfaces and then screwed the halves together. You wuold have to make all the cutouts for screw holes, etc., but it worked out well for me.
Good luck.

Try an auto body supply store.
I use this a non hardening caulking putty that comes in a 1/4" diameter ribbon.

Thanks all, I found some HVAC foam tape I'm going to try.

This has to be one of the most helpful forums on this website, but one quick question. I am having a difficult time finding the silver case that fits between the heater core and the black heater box, would you have any idea where i could find one? This post is the first time I’ve seen one yet.

Are you talking about the A/C evaporator?

If you are talking about the evaporator I have one, and most of the other parts.

I believe the part you're talking about fits inside of the heater core box. You can try the guy below, I've used him before

http://thepartguy.com/index.html

Good luck

Hello Pete67400, All I can say is WOW!!!!!!!!!! probably the best description of a a/c rebuild out there. I would like to know where to get my evap box that goes under the passenger side dash reconditioned like the one in your pics? Thank you Joe Cuyler. [email protected] is my email. 67 Original regimental red, automatic,p/s,p/b,a/c. Original smog motor and two speed trans. Only thing not original on this car is where someone cut holes to fit rear package tray speakers Built in lords town oh. sent to san louie obispo, Ca.

Hi Joe! I don't know where you could go to get the heater box reconditioned. I took mine apart to clean and repair it. I bought new foam door gaskets from one of the usual Firebird/Camaro parts places. I painted the housing, but probably should have left it with the bare fiberglass gelcoat for correctness.

Pete

Hello Pete, Are you still around? Long time no speak!!!! I see your ac had a three prong resistor on top of the suitcase. Shouldn't that be a 4 plug connector? I read somewhere that tree was for non ac cars. However, my donor car had ac and had the three prong resistor. Would it be that I have a smog pump from california? I wouldnt think so. I also need a wiring diagram for the ac. I have a 12 gauge wire coming from relay that has a 20 amp fuse. Does that go to alternator? I have some extra parts from the donor if needed. Thanks again Minnesota nice.