Classic Auto Air

[Kern Dog]

In 2019, I pulled my inoperable original heater/evaporator unit from the car and installed a complete kit from Classic Auto Air. It was my first time doing an A/C job and I was lucky to have decent instructions to get me through it.



 I installed the components almost to the letter, only deviating with the route of the #10 line. By 2022, I finished other tasks and was finally ready, so I took it to get sucked out and charged but the man disregarded the instructions. He didn't run a vacuum for 30-45 minutes, it was maybe 15?  Then he filled the system with the engine running. CAA clearly stated that it needs to sit 30-45 minutes under a vacuum and to NOT charge it with the engine running. That latter confuses me because the compressor looks like almost any other Sanden unit you see in many other later model cars. The mechanic just went ahead and did the service the same way he does newer cars.
The air blew cold so I figured I was in the clear. By Spring of last year, the air blew warm. Either the system has a leak or the compressor has failed. The compressor makes no noises. I don't see any obvious leaks anywhere. The heater blows air as hot as a new car but the A/C needs help.
I recently did a Vintage Air installation in a friend's 68 Satellite. That project is to the point where the system can be vacuumed and charged. Vintage has nothing in their instructions about the charge procedure. I can't find anything online either. I'm having a shop charge the Plymouth's system but for my Charger, I'm going to do a leak test by hooking it to the vacuum pump and seeing if it holds.
Stay tuned...

[Gold Rush]

I just finished installing my '74 SE's CAA (firewall forward) upgrade system and having it professionally purged/charged last month.  The thing is blowing 47 degree air so I'm hoping this triple black won't be an oven in the west Texas summer! Went for a ride a couple weeks ago and my passengers commented a couple times how WELL the a/c was working.... So far, so good!!!  img]https://flic.kr/p/2pEfmwx[/img]

[Kern Dog]

Yeah, mine worked well too. I pulled the engine in Summer 2022 due to a flat cam. I left everything connected but when I got the engine back in, it was Winter. By Summer 2023, the air wasn't blowing cold anymore. Either I tweaked something or failure was due to happen anyway.

[Gold Rush]

Doing the vacuum leak test is a good idea.  If it's a slow leak, that would eventually cause the line pressure switch to cut out not letting the clutch activate.  If you find that to be the case recharging the system and adding dye will tell you were the leak is.  Of course then you go through repairing and recharging again....

[Kern Dog]

Oddly, it seems that the compressor clutch stays on with this system even when you have the temp controls on HOT.
I called Classic Auto Air today and explained that I'd lost the cold air but the heater and mode selector works great. The man thought IF the heater control valve were stuck OPEN, it would heat the cold air that is trying to come through the vents. This assumes that the system has adequate pressure and refrigerant in it. I was at around 10 PSI a few weeks back when I added some freon. It came up to around 25 which the man said is within range.
I did attach the gauges and vacuum pump today. It wouldn't get past 20". I shut off the pump and the gauge did stay up near 20 but drop slightly. The hoses and gauges I have are old and show age cracks so maybe they don't hold past 20" anyway. I pressurized the system to approximately 40 psi and sprayed the connections with soapy water. I saw no bubbles moving anywhere. Maybe it is airtight.
I wish that I'd have called the CAA tech line first today...Instead, I was waiting for the vacuum pump to evacuate when I called them. Now all the Freon has been sucked out and it wouldn't blow cold air anyway. Now what do I do?
I guess I can start it up and see if it blows the same hot air no matter what temperature I choose. The man suggested that I pinch the heater hose with the control valve in it to see if the air temperature changes.

[Kern Dog]

A bit off topic.....I've been doing a Vintage Air installation on a friend's car. I haven't had much luck charging A/C systems so I took the '68 Plymouth in to get the A/C filled. The man tried to pull a vacuum but could only get to 10", then it dropped to zero once he shut off the pump. I had the exact same result here when I tried the same test yesterday. I thought maybe my hoses or gauges were just old and messed up but when two people get the same result, it means something.
Back at home, I replaced a line with 2 45 degree fittings and retested it. It came up to 20" like my Charger does so maybe both systems are okay and that the vacuum pump is just not powerful enough to bring it to the 30" number.

[armor64]

i cant speak to specifics, but for my vintage air kit, the guys who charged it (did my safety/alignment in same appt) he said he was able to do the vacuum pull for over an hour while working on the alignment machine, and so far 2 summers has worked out (hoping this year it works too lol)

[Kern Dog]

When a shop charges well over $140 an hour for labor, I wonder how many actually leave the car sitting in their service bays waiting for the full hour. I strongly suspect that they run the vacuum to test for leaks and to evacuate, then fill it. Time is money for a business.
Yesterday at that shop, I told the service guy that these aftermarket companies stress the need for the extended vacuum session. He didn't comment. He probably didn't want to talk about how they do it there.

[b5blue]

Buy a pump. (I did.)

[Kern Dog]

I thought that maybe the hoses, gauges and manifold could be leaking and not allowing the pump to pull to 30" so I bought these:



 



I still couldn't get to 30". The best I did with the new stuff was 22" I took the hose off the pump and checked with a vacuum gauge for testing intake manifold vacuum.....

[Kern Dog]

The vacuum pump was a turd.
Auto Zone has a "loaner program" with some tools where you pay for it, use it and return it in the same condition and they refund the full amount.

I got another pump....



It is smaller than the Harbor Freight pump.

 

Good news though...



It shot right to 30" and stayed there. I shut down the pump and closed the valve so the car was on it's own. It held pressure so it looks like the system is airtight.
Why did the air stop blowing cold then?
Bad compressor? It makes no bad sounds and the clutch was working until I evacuated the system.
The guy at Classic Auto Air thought that the heater control valve could be stuck OPEN. This would heat the airflow all the time even if the air is supposed to be cold.
I'll pull the valve and look through it. It should be see through when the inside controls are on HOT and it should be closed off with the controls set to COLD.
To recap:
I thought the system might have been leaking above 20" and not allowing the pump to reach it's potential.
It WAS at it's potential, it is a piece of junk.
I hope to get the system filled in the next few days.
Wish me luck!

[b5blue]

My CAA system came with a "chip" did yours? I would suck it down for no less than 45min and sit overnight to test.

[Kern Dog]

I recall that mine had some type of computer chip that was used to "bench calibrate" the controls.

[will]

I had this exact problem. I put a serpentine system in and when I went to charge it the air was hot. Look at the heater control valve, mine was not functioning properly. I had to take the motor off of the valve and reorientate it to make it function correctly. The coupling had slid on the motor and wasn't in the right position. Even though the valve was commanded to close it was still open. The CAA guy I spoke with was the same guy who made the valves a long time ago. I forgot his name.

[Kern Dog]

I took the HVC out of the heater hose line and saw that it does open and close. The problem is, the dash control panel isn't intuitive as to it's orientation. In other words, the direction of the slide is fore and aft...toward the radiator  or toward the trunk. The graphic that is on the panel display cannot describe a fore/aft properly and to make it worse, the instructions in the installation kit state that with the slide FORWARD, you are in the coldest setting. No, that isn't right. FORWARD means to the front. It is backwards. The temp control slide is COLD with the slide button toward the trunk. The temp is HOT when towards the front.
With that sorted, the HCV is working as it should. I did order another one just to have a spare.
I put the system under a vacuum again and am currently waiting to add Freon.

[will]

I took the HVC out of the heater hose line and saw that it does open and close. The problem is, the dash control panel isn't intuitive as to it's orientation. In other words, the direction of the slide is fore and aft...toward the radiator  or toward the trunk. The graphic that is on the panel display cannot describe a fore/aft properly and to make it worse, the instructions in the installation kit state that with the slide FORWARD, you are in the coldest setting. No, that isn't right. FORWARD means to the front. It is backwards. The temp control slide is COLD with the slide button toward the trunk. The temp is HOT when towards the front.
With that sorted, the HCV is working as it should. I did order another one just to have a spare.
I put the system under a vacuum again and am currently waiting to add Freon.

  I understand. I had heat in both positions, so I dug a little deeper and that valve wasn't doing its job. I had to turn the actuator and get the coupling aligned on the valve for it to work. I really thought I was shreading plastic splines when I was turning the actuator, but it works now. Once I put the car back on the road I will get temps. It was really cold a/c when I put the car away.

[Kern Dog]

It gets weird.
I evacuated the system and added 2 cans of R-134. Just as the second can was done, the engine stalled. NO spark.
Yeah...It would crank fine but not start.
This random issue happens occasionally and follows no pattern. It can be after the car is sitting. It can be after it just ran fine. I touched nothing under the hood, it ran 5 minutes ago and won't start now for no obvious reason.
I've swapped ECMs, ballast resistors, coils and sometimes, ONE of those things either made the difference or the car just decided to start up no matter what I swapped. I've even resorted to spraying ether down the carburetor. THAT sometimes helps and it starts....OR it was going to start at that point anyway and the ether made no difference.
The air blows cold now though!

[John_Kunkel]

The guy at Classic Auto Air thought that the heater control valve could be stuck OPEN. This would heat the airflow all the time even if the air is supposed to be cold.
I'll pull the valve and look through it.

Simple test for a heater valve...with the engine up to operating temperature, grab the hose going into the valve and the one going out, if both are the same temperature the valve isn't closing.

I'm not familiar with Classic Air but Vintage Air systems almost always calls for 1.8 pounds (28.8 ounces)  of R-134. If you charged the system with two 12-ounce cans, you're likely under the recommended charge.

The air blowing cold is a relative term, it's a good idea to add a thermometer to your A/C tools to measure the temperature as it exits the register.

https://www.amazon.com/InterDynamics-Conditioner-Thermometer-Fahrenheit-TH-27/dp/B002G1PBHI/ref=asc_df_B002G1PBHI?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80608063550927&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584207590415627&th=1

[Kern Dog]

Thanks.
Yeah, I could have just felt the hoses but the man at CAA said that the valve could be partially open and still cause trouble. He also said they can be closed and still leak so I pulled it and looked through it, then pushed the temp to COLD and it closed. I then held it upright and poured water in the end and nothing dripped from the other end.

During the R-134 fill, the low side numbers were in spec but the high sides were lower than I expected. The man said 17 to 35 for the low side and around 175 for the high.



It was 65 degrees so maybe that explained why the high side barely crested 100, 110. I should have taken a picture.

[Kern Dog]

Just to update:
I mentioned that during the second can of 134, the engine lost spark and wouldn't restart. This is an issue that randomly has happened for 12+ years. I've never been able to pinpoint exactly what causes it but since I was in no hurry, I started unwrapping some of the wiring to look for problems. I still found nothing but I did clean the terminals in the bulkhead and used some dielectric grease. The coil had adequate voltage, the ECM had power. The leads to the distributor didn't but I need to test it when the car consistently starts to see if they only have power when connected to the distributor itself.
It has been cold and rainy all week so I haven't been able to check to see if the A/C is as cold as I hope that it is.

[b5blue]

Check the big white connector under the steering column also. I use D-100 contact cleaner by Caig Labs on everything and swear by it.

[Kern Dog]

Ups and downs. wins and losses.....
The A/C has been finicky. I thought I had it charged right but I admit, this stuff is new to me.
I went to Los Angeles for the Spring Fling and noticed the air wasn't blowing cold on the way there. On the way home, one of the guys in our caravan went to work. He put the gauges on it and added refrigerant. It blew cold, so I left. That was over a week ago.
Today, I checked and it is blowing warm again. Maybe I have a leak. The friend offered to work on it again so I'll take him up on it.

[b5blue]

Have them add dye to trace a leak.

[Kern Dog]

I am a bit stubborn....(Big surprise, huh ?) I just can't get myself to bring this car to a shop except for an alignment! I built the car, I'll be the one fixing it. (With a little help of course)
I have a buddy a couple towns over. I'll make a trip out to see him and report back when we get it figured out.

[John_Kunkel]

A/C leaks can be a nightmare even for the pros. The dye only seems to work for spotting leaks if the gas leakage is accompanied by oil leakage and the dye is hard to spot in closed places like the evaporator box. Sniffers have their limits too.

A lot of pro shops are now using nitrogen to test for stubborn leaks.

[Kern Dog]

Yes.
I recently did an A/C install on a '68 Plymouth. I put a vacuum pump on it but couldn't get it to even hold 20" of vacuum so I took it to a shop for evacuation and a fill. They found 2 minor leaks using Nitrogen, then after I fixed the leaks, they charged the system and all is well.
With my car, I did get it to hold 30" of vacuum for over 45 minutes so I figured I was in the clear.
I filled the system with the appropriate amount of R-134 and it seemed fine....but it was in the mid 60s that day so it wasn't the right time to test it.
A skilled friend of mine thinks that despite it holding vacuum, he thinks it can still leak when under pressure.
The Classic Auto Air guy said it needs to be between 17-25 psi on the low side and around 150 on the high side.

[Kern Dog]

Mixed bag of nuggets today.
Randy changed the Schrader valves on the low and high side ports, evacuated the system, put it on a vacuum at 30" and let it cook for 35-40 minutes.
It held so he filled the system with R-134. The air through the vents felt cool but not cold. I figured that since the car sat in the sun, the dash was hot and it takes  awhile to cool off the metal parts.
I parked the car with the windows closed and we went to lunch. Afterwards, I hung around the shop awhile. It sat for about 2 1/2 hours.
On the way home, it blew warm air the entire 78-80 miles.
At home I noticed that the compressor clutch wasn't staying engaged. It would click on for about 1/3 of a turn, disengage, then about 10 seconds later try to engage again.
I was advised to bypass the hi-low switch so I ran a jumper wire to it.
The compressor clutch stayed engaged and the air started blowing cool....then got really cold just like it should.
The low side read 26, the high side was 110. The load of the compressor wanted to bog the engine. A few minutes in, the belts would sometimes squeak. Sometimes the compressor knocked like a lawn mower with no oil in it.
I'm wondering if the compressor is failing. The numbers that it showed on the gauges seem too low.
I will call the Classic Auto Air tech line tomorrow and see what their guy thinks.

[Kern Dog]

As the world turns...
More strangeness to report: To recap, yesterday Randy evacuated then charged the system using a scale appropriate for most systems that use R-134/Freon.



It blew cool right after the refill but blew warm 2 1/2 hours later for the ride home.
When I got home, I noticed that the clutch in the compressor wasn't staying engaged. Randy suggested that I bypass the pressure safety switch so I did. Now the compressor clutch engaged and the air blew cool, then it turned cold! Maybe the air blew warm on the way home because the compressor clutch wasn't engaging at all.
I figured I'd need to replace the switch so today I bought a new one.
THIS afternoon, I started the car and tried the A/C. For some reason, it worked just fine. Oddly, the gauge readings seemed normal today.
It turns out that I didn't have the A/C manifold hoses and fittings connected right. You're supposed to tighten the knobs on the ends to fully open the Schrader valves in the high and low ports.
Today the low side was around 18-20 and the high side read 200, then 225, 250 and 275. I don't know why the high side was reading that high.
I talked with Dwight from Classic Auto Air this morning. First off, he said their systems are supposed to have 24 ounces of Freon. Many techs just dump an unknown amount in and look at the gauges to determine when enough is enough. That is what my friend did.
Dwight said that the low should be around 17-20 and the high side should be around 100 plus the ambient temperature. If it was 90 degrees out, the high side should be 190.  Here is a scale I saw online:



Vintage air systems are similar:



The knocking I was hearing from the compressor is gone. I don't know why. It is working and blowing cold though.
I do hate it when something breaks and you don't know why...I also don't like it when something suddenly works without actually fixing anything.

[armor64]

it sounds like a mix of too much refrigerant and potentially causing a faulty in the pressure switch. i remember in the vintage air paperwork, there was a page in each instruction set with a massive warning about the exact weight of oil and gas to put in, and not to add oil if new VA compressor, as they come with the "needed amount". the aftermarket systems do seem to be more touchy than any factory systems, but well worth the cool air in summer.

[Kern Dog]

Thanks, I agree. They state 24 ounces of R-134.
My friend seems to prefer to go by the scale I posted above. It concerned me a bit.

[Kern Dog]

Have you ever dealt with something that technically should not work but somehow does?
I had those high readings on the high side yet the A/C blows cold air just fine.
Heck, man...I'm not skilled enough to know why it works. I'm glad that it does though.
I would like to know. I haven't called the CAA guy yet. Maybe I'll check with him this week just to satisfy my curiosity.
I went on a 180 mile road trip yesterday...90 miles to and 90 miles back from a car show. It was 85 degrees after the show. I would have been fine cruising home with the windows down but the wife wanted the A/C. I'm happy to have her along so what the heck!

[Kern Dog]

Air conditioning was stuff that we ripped out of cars for years. If I were still single, I'd probably not even bother with it in the classic cars. I like the simpler look of a car that doesn't have it.
A/C makes the wife more comfortable so I did it to make the car rides better for her.
This town has some Mopar guys but most are bench racing types that never do anything with their cars. Our local Mopar club has some nice people but nobody that is as active with their cars as I'd like. My last Mopar buddy sold his car and has no interest in getting another so the wife is my ride-along buddy. That is fine, since she is a great lady.

[Kern Dog]

This has been a frustrating journey.
The air blows cold after a service, then the car sits awhile and blows warm when I come back to it.
Sometimes we have to admit defeat and consult a pro. This is one of those times. I don't have the equipment to trace leaks and it seems like that is what I need to get this system working consistently.