AC compressor upgrade, 1980 TA

[5th T/A]

When purchased in February of 2020 my car had the original GM A6 compressor. The AC worked fine, although there was oil leaking from the front seal, a typical problem with this model compressor. I assumed the refrigerant was upgraded from R12 to R 134A because it had the quick coupling connectors on the service ports. But there were no labels stating it was a R134 conversion. During the engine upgrade I removed the compressor and condensing coil. Once I had the car back together, I evacuated and charged the system with R134. The AC worked fine, although it still had some oil around the front seal. Since I like a clean engine compartment I ran the AC very little to minimize the oil and dirt.

The ceramic seals were so prone to leaking that GM put a metal shroud around the compressor clutch on some Cadillac and Buick models. Doing some research, I found that if the car sits for long periods of time without running the AC, new seals often still weep oil. There is an aftermarket lip seal made for these compressors now that are supposed to be less prone to leaking oil. Going to car shows I have seen many cars retrofitted with a modern compressor or in some cases a complete new system such as vintage air. Other than a slight amount of oil from my compressor everything worked fine. I came across a compressor upgrade kit from Original Air / Classic Air. The kit includes a new compressor, compressor mounting bracket, accumulator, rubber lines, new O-rings and Orifice tube. I did some more research on TAC and other sites and found people didn't like the compressor mount included in this kit and recommended the Vintage air compressor mount.

Here is the Kit from Original Air / Classic Air.

IMG_3965 by Lawrence Alexander, on Flickr

IMG_3963 by Lawrence Alexander, on Flickr



Here is the compressor mount kit from Vintage Air.

IMG_3966 by Lawrence Alexander, on Flickr

Here is a comparison of the original A6 compressor, top of photo and the Sanden type replacement at the bottom.

IMG_2573 by Lawrence Alexander, on Flickr

Out of curiosity I weighed all the old compressor and associated parts compared to the new in the kit. The original compressor and parts weigh 44 lbs. versus the upgrade kit at 21 lbs. Also from what I have read the A6 compressor needs 10 - 15 horsepower to operate versus the replacement needing 2 - 5 horsepower.

So, on September 7th I ordered the Compressor upgrade kit directly from Original Air. The kit arrived October 8th. On the same day I ordered the Classic Air compressor mounting kit from Summit racing. It arrived on September 9th.

Unfortunately there were issues with Classic Air sending me the wrong compressor.

More to come!

[b_hill_86]

Thanks for the progress so far. I’m one of those that installed the entire Classic Auto Air/Original Air Group kits. For the record I’m still not a huge fan of their bracket but my biggest complaint regarding it was ridiculous belt flutter when the compressor was engaged and I was at highway speeds (70mph with a 3.08 gear @ about 2700). Since then I presume the belt has loosen up some or become less rigid rather and it has improved quite a bit. I still wonder if adjusting the tension would improve it at all but I can live with the current state of it. I did make a little bracket I added to provide some rigidity to the compressor mount. I’m not sure if that has had any effect or not to be honest.

I’ll be interested to see what your thoughts are on the VA bracket.

[roadking77]

Following along

[5th T/A]

As I mentioned yesterday the upgrade kit arrived on 10/08 and was well packaged. I opened the kit and took inventory. These are the installation instructions I received.

img20231114_19042184 by Lawrence Alexander, on Flickr

On 10/09 I called Original Air and told them the installation instructions were not legible. They immediately sent me a .pdf with the instructions.

On 10/10 I started mocking up the pieces and realized the suction and discharge hoses they sent me were too small at the compressor end. I called Original Air and explained the hoses would not fit the compressor. I was told I had to submit a warrantee claim. I immediately filled out an online claim form with a picture showing the difference in hose size versus the compressor fittings. On 10/12 received an email saying they will get a new discharge hose sent out to me. Before I could reply back saying both hoses would not fit (1:15 latter) they sent another email. The second email reply " As we're looking into the issue it appears that what actually happened is we received an incorrect batch of compressors from our supplier". "They won't fit the mount or the discharge fitting". "We are looking to see if we have any of the compressors in-house right now". After receiving illegible installation instructions and the wrong compressor I am questioning the lack of attention when they packed my kit that took a month to assemble and ship. Nine days pass without any email or shipping notification of the correct compressor. I call back on 10/19 and ask what's going on. They say they want to me to send back my compressor and they will switch the plate at the rear of the compressor to one with the correct fitting size. My reply is this is unacceptable, I want the compressor factory sealed sent to me. They reply it will ship on 10/20. On 10/26 I call back asking for tracking information on the compressor. On 11/05 I finally receive what appears to be the correct compressor.

[5th T/A]

When I purchased this kit I liked the idea that it was engineered with everything I needed for the upgrade, not just a compressor and bracket. leaving me to make up hoses and fittings. Also came with the accumulator, O-rings and Orifice tube.

Using a couple of cans of AC flushing solvent I flushed out all the solid refrigerant lines, the evaporator core and the condenser. The evaporator needed half a can before the solvent came out clear. The condenser needed almost two cans of cleaner before solvent was clear. What came out of the condenser was pretty disgusting and made me question how my AC system managed to work.

Before I could flush the evaporator I had to remove the orifice tube. I tried using a thin nose piler but was unsuccessful. I did some you tube research and found out that this can be a difficult task A special tool is often required and sometimes requires heat. In some cases the orifice tube can break, requiring replacement of the evaporator coil.

I found removal tool online, cost $12.00. the tool grips the orifice tube in four places. It took three tries before I was successful in removing it. I was getting a little nervous. What I found was a little alarming metal debris, non ferrous in the tube.

Original orifice tube installed in evaporator, somewhat damaged from my piler.

IMG_2604 by Lawrence Alexander, on Flickr

Original orifice tube removed.

IMG_2605 by Lawrence Alexander, on Flickr

New Orifice tube, attached to removal / installation tool.

IMG_2600 by Lawrence Alexander, on Flickr

More to come!

[Warren Seale]

That orifice tube removal tool causes me problems.  It tends to slip off of those two little tabs at the end of the orifice tube housing.  Sometimes it also damages the tabs.  Because of this, I typically use a hemostat and clamp it to the end of the orifice tube housing.  That works all of the time.

I'll use the orifice tube tool to install the new part.

[b_hill_86]

Sad to see their quality control hasn’t improved or may have gotten worse. I think post crash I wrote a write up on my experience so it should be up still. Following for further experience and opinion.

[FormTA]

This is all really interesting.  I unfortunately installed a 4th gen evaporator because I figured it was a better design and I had it from the car I parted out for the LS engine. My plan was to use all the 4th gen stuff. Some day I'll get to it.i wish I could use a kit like you guys. Great post guys!

[5th T/A]

The installation is almost complete. With the new compressor installed the original AC belt was too short. It took several attempts before I found a slightly longer belt that fit correctly. Using the Vintage Air Steel-eez mounting bracket I ended up using a Gates 7597 belt, 13/31" X 60 1/8". I have had the system evacuated and holding a Vacuum for almost a week. I still need to charge the system and haven't decided if I will wait for warmer weather.

This is what I started with, original GM A6 compressor.

IMG_0213 by Lawrence Alexander, on Flickr

New Compressor upgrade kit from Classic Auto Air, using compressor mounting bracket from Vintage Air. Circled is the fuel return line from my EFI throttle body. With the original compressor I ran the wiring and fuel return line over the rear mounting bracket. With the new compressor I didn't like the fuel line laying on the rocker arm cover. Temporarily I put a piece of heater hose over the line until I can get a longer rubber fuel line and run it off the rear of the engine (for a less cluttered look).

IMG_2658 by Lawrence Alexander, on Flickr

Some may recall I purchased my engine from another Forum member "Spoon". The dipstick tube installed was for a non-AC car. The diameter was smaller and I could not install the dipstick extension that is connected to an upper front compressor bracket. With the compressor sitting over the dipstick checking oil level was a challenge, especially on a hot engine. With the new smaller compressor access to the dipstick is much easier.

IMG_2659 by Lawrence Alexander, on Flickr

A picture of the Vintage Air mounting bracket. Brian was curios about belt flutter. Runing the compressor without refrigerant doesn't put any load on the belt. I will provide an update after I charge the system regarding belt flutter and cooling efficiency.  I know, I need to do some paint touch up where the adjusting bolt rubs.

IMG_2662 by Lawrence Alexander, on Flickr

Vintage Air diagram of mounting bracket.

IMG_2663 by Lawrence Alexander, on Flickr

[roadking77]

Very nice, now on my wish list to Santa

[b_hill_86]

Nice! Thanks for the update and pictures. Looking forward to how it turns out.

[olds403]

I did this on 403 as well using a Sanden FLX7 compressor.  Just buy the bracket.  I can make the lines for anyone much better than a kit which does not exist for the 403

[5th T/A]

I did this on 403 as well using a Sanden FLX7 compressor.  Just buy the bracket.  I can make the lines for anyone much better than a kit which does not exist for the 403

I liked the idea of a ready-made kit with all the pieces fitting properly. I also wanted crimp connections for the hose and didn't want to buy a crimping tool or send the hoses back to get crimped. While it took a while to get the correct compressor, I was happy with end result. Its cold outside now so I will wait approximately six months for warm weather before charging the system. At that point I will report on cooling performance and if I get any belt fluttering using the Vintage Air compressor bracket.

[jbanna]

It may be too late for you now to help, but I converted my original R-12 system to R-134 about 25 years ago, without any additional changes, and it's been good enough up here in the northwest; however, I did replace the compressor with a rebuilt one, and the high pressure hoses about 10 years ago...I just had it recharged last fall, having to replace a broken thermostatic switch, and so far so good...

[5th T/A]

I have been anxiously awaiting warmer weather so I could charge my AC system. Last December I had the system holding good vacuum for at least a week. A couple weeks ago we had some warm weather, so I attempted to charge the system. I hooked up my AC gauges and no longer had a vacuum. I connected my vacuum pump, pulled a vacuum, but it wouldn't hold. I went to Harbor Freight and picked up a refrigerant leak detector. The tool cost about $60.00, easy to use. I had to add a small amount of refrigerant to the system for the detector to sniff out and located the leak in a few minutes.

My compressor upgrade kit included new rubber refrigerant lines, rubber O-rings, a new accumulator and compressor. All a good idea to replace these on a 44-year-old car. Somehow I managed to clip an O-ring on the hose going to the accumulator. Surprising it didn't leak right away. I didn't have another O-ring the correct size, so I ended up using the 44-year-old original, O-ring that came with the car (hopefully not a decision I will regret).

Today we had a decent weather do so I charged the system. The original refrigerant capacity label on the evaporator box gave a capacity of 3lbs. 4 oz or 52 ounces. R134A is supposed to require only 70 - 80% of freon compared to R12. So a range of 36 - 41 ounces would be appropriate. I had three 12 ounce cans of R134A and unfortunately lost most of the first can by not having it mounted correctly.

With less than a fully charged system I was able to bring my AC vent outlet temp down from 75 degrees F to 48 degrees F. It actually felt pretty cool blowing out of the vents. For now, I will wait for a good hot summer day before adding additional refrigerant. I feel confident the additional refrigerant will bring the temperature down another 10 degrees or more.

The new compressor is quiet and smooth, no belt flutter. The only sound heard is the electric clutch engagement. The clutch sound was not heard while sitting in the car.

[b_hill_86]

Curious to see where you end up with your refrigerant. When I did mine I shot for the same 70-80% mark and found it to be too much if I remember correctly. Mine still works but I feel there is room for improvement.

[jbanna]

Mind took three pounds to recharge last fall, and the a/c is almost as good as the original R-12 system, but I didn't measure the vent temperatures...

[Wallington]

Almost as good? Is it still using the stock R-12 factory system? Same pressure switch settings? Same R-12 orifice switch? Same stock condenser? R134a is able to surpass R-12 even with half the adjustments it can use.

[FormTA]

Glad to see you got this up and functioning Larry! Someday I will attack mine. I will have to purchase my own hoses and fittings somewhere amd my own compressor and mount for the LS engine.  Not that I need AC because once summer hits my T Top go in the garage and I only cruise without them.

[nUcLeArEnVoY]

Assuming it's been converted to R134a (you mention the schrader valve snap-on fittings), did you consider swapping out to the parallel flow condenser? R134a has better heat conductivity than R-12 and therefore operates at higher pressures, and so a condenser with more surface area to absorb and dissipate that heat is necessary. That's why it's recommended to upgrade to a parallel flow condenser to get the most out of an R134a conversion.

[jbanna]

I had a shop do the conversion many years ago, so I'm not sure if they changed any of the stock switches, but I don't think so; however, I had to replace the thermostatic switch last summer.  I know I can swap out the stock condenser for a larger one, which would make the 134a much cooler, but that's not something I want to do anytime soon, especially since it's not too hot here and I've got other more pressing projects to complete...isn't that the way it always works?

[5th T/A]

Assuming it's been converted to R134a (you mention the schrader valve snap-on fittings), did you consider swapping out to the parallel flow condenser? R134a has better heat conductivity than R-12 and therefore operates at higher pressures, and so a condenser with more surface area to absorb and dissipate that heat is necessary. That's why it's recommended to upgrade to a parallel flow condenser to get the most out of an R134a conversion.

Really my only complaint with the original GM compressor was it would sling a little oil out of the front seal when I ran the AC. The few times I did use it the cooling performance with R134A was good. I am a little obsessive about keeping the engine clean, so I avoided running the AC. Honestly, in nice weather I enjoy cruising with the windows down. Now that I have a compressor that hopefully wont spray any oil, I will be more likely to use the AC. Especially on a hot day sitting in traffic.

If I am unhappy with the AC cooling performance, then I won't hesitate to upgrade to a parallel flow condenser. Do you have any personal experience with upgrading to the parallel flow condenser?

I will say the new compressor seems to run quieter and smoother than I recall with the original GM A6.

[5th T/A]

Yesterday I was able to test the AC out in real hot weather conditions. Because of some complications in charging, I am not sure of the exact amount of R134 I have in the system. My local Pontiac club had a cruise and BBQ to a state park. Round trip was 190 miles, no freeway driving, back roads and heavy stop and go traffic with outside air temps close to 90. I was very comfortable with the blower set one notch down from max speed, eventually set it another notch down until having it at the lowest speed. I was almost getting cold and rolled down the driver's window to see if the outside temperature had dropped way down, but it was still toasty outside.

My car has a 180-degree thermostat, sitting in traffic through a couple light cycles the temperature gage on my EFI display screen got as high as 195 degrees. At the same time the Pontiac dash gage was displaying 220. I feel the FAST EFI screen is accurate and I am not concerned.

I am calling this project done, I am satisfied with the end results.

[b_hill_86]

I wish I knew how much refrigerant you had in your system. I ended up adding a little to mine recently and got about a 40-50° drop in vent temp from ambient which I’m happy about but at idle the vent temp comes up more than I’d like and the other day with ambient around 90 I started warming up to about 200-205°when I’m usually around 180°. I’m guessing there is room for improvement still. I reached out to OAG asking about the charge level considering all of my components forward of my original evaporator core are replacement parts and I have yet to hear back. After about 4 weeks

[5th T/A]

Brian, I wish I could give you an accurate number for ounces of R134A in my car. Maybe a month ago I contemplated having a shop that does AC service evacuate the system and recharge to the recommended amount. That should be 36-41 ounces.  So on an 80 degree day I was driving to an AC shop to have them accurately charge the system. I was running the AC and almost at the shop and felt the system was cooling well. My thought was why spend the money to do this when it’s working well. I knew the system was not overcharged. I came to the conclusion that if it’s not broken, don’t fix it. Keep in mind that I live in the Midwest where a hot summer day is in the low 90’s. If I lived in Phoenix or south Florida the demands on the system would be much higher and I might have to go to a parallel flow condenser.

[b_hill_86]

Yea, I don’t blame you at all. I have similar feelings although I obviously lack certain knowledge or skills to refine the performance of my system. I’m hesitant to mess with it at the moment though since it blows SO cold while driving. Plus, I know there are other factors such as condenser air flow at idle that could be contributing.

Just for clarification, does your system blow cold at idle as well?

[5th T/A]

Mine blows cold air while at idle, I couldn't feel any temperature difference between sitting at a stop light versus cruising speed.

I installed the factory spec orifice tube. They do sell a variable Orifice tube that is supposed to help cooling in stop and go traffic.

Also, when I had issues with the wrong compressor be sent to me, I found they had one phone number for original air and another phone number for Classic Air. Supposedly the same company but Facilites are in different geographic locations. I remember leaving messages at one number and not getting a call back. I called the other location and got a real person.

IMG_4188 by Lawrence Alexander, on Flickr

IMG_4187 by Lawrence Alexander, on Flickr

[b_hill_86]

Thanks for the info. I’ll have to keep plugging away. I’m glad you mentioned the orifice tube though. I have a fixed but wondered about the variable. Clearly yours is blowing cold though with the fixed. At least I know there’s hope.

[Warren Seale]

A quick way to know if you have enough Freon in the system is to run it whilst feeling the low pressure tube right at the compressor.  It should feel cold.  This assumes there is nothing else wrong with the system.  The factory service manual also describes this procedure as well.  Overcharging is really pretty tough to do because the system won't suck in more than it can fit.  You'll find that the Freon is not leaving the can at this point no matter how long you wait.

[5th T/A]

Thanks for the reply. The low pressure hose at the compressor is very cold when the AC is running.