'69 AC Compressor

[Pat K.]

Trying to determine if this is an original compressor for my car. The code number can no longer be read, but there are impressions on the label. The model number is 5910693 and the code on the bottom right is 693.

Any comments would be appreciated, thanks.

Pics are attached

[Jeffrey S.]

Re: '69 AC Compressor

Pat:
The 693 compressor was used in early '69 cars. Late '69 used the 5910740. It's hard to read the date of the drawing change in my AIM but it looks like August of '69. Most likely this was the part scheduled to go into the '70 but since that year was delayed and '69 ran long, it was just used for the remaining '69 production. Hope this helps.
Jeff

[Pat K.]

Re: '69 AC Compressor

Jeff,

This car is an early '69 (Feb), so this may very well be the original compressor. Too bad the code number is no longer ledgible, but the label does appear to be original.

I think I will have this compressor rebuilt instead of buying one already refurbished.

Thank you,

Pat

[Edward J.]

Re: '69 AC Compressor

Jeff,
The Question Is What Really Needs Replaced Or Rebuild, The Compressor Front Seal Looks To Be Dry, You Have A Correct Manifold, The Decal Looks Correct,by The Way The Manifold And Hoses Are Not Easy To Come By, Maybe A Little Sprucing Up With Paint And Cleaning, New O-ring Seals, As Far As The Date Goes Maybe There Someone With And Idea -you Cannot Reproduce The Label As The Exactly Like Factory.

[Pat K.]

Re: '69 AC Compressor

Edward,

A good question... I plan on retaining as much of the original parts as possible and sending my compressor and muffler to Old Air Products for a rebuild. I realize they use steel and the crimp is different but I can't trust hoses that are 40 years old and I don't think this AC has been run for 30+ years.

Question - I'm a novice at the AC system, but I'm using the Service Manual plus other info as a guide and I don't see any mention of "Manifold". Is this part known by different names?

Thanks,

Pat

[Jim T.]

Re: '69 AC Compressor

I am still using the original compressor and hoses on my original owner 70. It has not been a daily driver for about 18 years or so, but it is driven sometimes. The system has held up well having 160k miles except for the front seal seepage.
I recommend one check you can do. Look in your service manual at the expansion valve. You will find there is a small filter screen that filters the R12 coming into the expansion valve from the condensor. The R12 pases through the dryer before it goes through the condensor.
Inside the dryer is bagged desiccant. If the desiccant leaves the dryer it will end up in the small filter screen in the expansion valve and your air conditioning system will not function.
You can easily check the screen by removing it. I used an easy out to gently remove it.

[Grant W.]

Re: '69 AC Compressor

Trying to determine if this is an original compressor for my car. The code number can no longer be read, but there are impressions on the label. The model number is 5910693 and the code on the bottom right is 693.

Any comments would be appreciated, thanks.

Pics are attached

Hi Pat
There is a date code embossed at the back of the compressor. This where the hose block attaches to. If your hoses are not cracked then don't change it. THey have part numbers on them and NOS originals are so hard to find.
Thanks, Grant

[Pat K.]

Re: '69 AC Compressor

I am still using the original compressor and hoses on my original owner 70. It has not been a daily driver for about 18 years or so, but it is driven sometimes. The system has held up well having 160k miles except for the front seal seepage.
I recommend one check you can do. Look in your service manual at the expansion valve. You will find there is a small filter screen that filters the R12 coming into the expansion valve from the condensor. The R12 pases through the dryer before it goes through the condensor.
Inside the dryer is bagged desiccant. If the desiccant leaves the dryer it will end up in the small filter screen in the expansion valve and your air conditioning system will not function.
You can easily check the screen by removing it. I used an easy out to gently remove it.

Jim - I actually have an original spare expansion valve that I picked up from a wrecked '69. The inlet screen appears to be missing, and it looks like it needs a good cleaning. A couple of questions:

1) Do you know where I can buy a new inlet screen?

2) What's the best way to clean it?

3) Can it be bench tested? I read somewhere you can put in an ice bath and the valve should open.

Thanks,

Pat

[Pat K.]

Re: '69 AC Compressor

Hi Pat
There is a date code embossed at the back of the compressor. This where the hose block attaches to. If your hoses are not cracked then don't change it. THey have part numbers on them and NOS originals are so hard to find.
Thanks, Grant

Grant - I plan on taking the compressor off this weekend and will look for the date code. Once the hoses are removed is it possible to have them tested for leaks? If they don't leak, then I will probably use them.

Thanks,

Pat

[Larry M.]

Re: '69 AC Compressor

Jim:

The inlet screen for the expansion valve is AC Delco # 15-512. It was used through 1985 and that part number is still active within the ACDELCO parts system. You might have to call them to see who still sells it. A picture is available on their website.

You can bench test by putting the curved bulb in ice water. The expansion valve should close as the bulb gets colder.

I would not try to clean, except perhaps wiping the exterior down with mineral spirits/paint thinner to remove any tar or adhesive.

Larry

[Larry M.]

Re: '69 AC Compressor

Agree with Grant. If the hoses look okay visually, I would try to reuse them. I would, however, blow them out very good with compressed air to remove any debris/crud from sitting around over the years. Also inspect carefully the end connections for corrosion or pitting.

Once everything is installed on the car, you must pull a deep vacuum to check for leaks. Any problems will show up then. You can also break vacuum with a small amount of refrigerant (1/4 lb. or so) and then have an AC shop or AC technician check for leaks with a Refrigerant Leak Detector.

I recently bought one (detector) for my car. Does an excellent job. A little pricey, but think of all the "friends" you'll make when they know you have this tool. I can recommend one if you want to pursue. I did a significant amount of research before I bought mine.....so I think it is one of the better/more cost effective ones out there.

Larry

[Pat K.]

Re: '69 AC Compressor

Jim:

The inlet screen for the expansion valve is AC Delco # 15-512. It was used through 1985 and that part number is still active within the ACDELCO parts system. You might have to call them to see who still sells it. A picture is available on their website.

You can bench test by putting the curved bulb in ice water. The expansion valve should close as the bulb gets colder.

I would not try to clean, except perhaps wiping the exterior down with mineral spirits/paint thinner to remove any tar or adhesive.

Larry

Larry,

A timing issue, I just posted this topic as a main thread as you were replying to this one, thanks for the info.

Pat

[Edward J.]

Re: '69 AC Compressor

Pat,
The Hoses Are Checked With Freon In The System, A Easy Way Is A Inspection Of All Fitting Areas For Signs Of Oil Residue- This Indicates A Sure Leak,the Other Way Is W/ A Electronic Leak Detector, There Are Quite A Few O-ring Seals Where Ever The Fitting Attach To Each Other , (compressor, Condenser, Expan. Valve, Etc.) Just Replaced Them All. -i Own A 72 W/ All Orig. Parts On A/c System No Leaks, Orig. Compressor- No Leaks. Ive Been In Auto Business For 35 Yrs.ive Installed Many Reman. Compressors Before, Sometimes Their Are Quality Control Problems W/ Reman. / Rebuild Parts -i'd Tell You To Do Only What You Need,you Can Remove Compressor And Change The Oil, Replaced Manifold O-ring Seals,if The System Is Presently Holding Freon, Theres No Need For Needless Spending -im Sure If You Think Like Most, These Car Cost A Arm And Leg To Restore.
p. s I assume the system was operating before you start the dissy. thanks Ed

[Dennis C.]

Re: '69 AC Compressor

I would caution against using compressed air to blow out any part of an AC system. Shop compressed air will contain moisture, oil particulates, and other contaminates that you may not be able to get out of the system prior to reinstalling. Likewise, whenever you open an AC system, you should seal the open ends of hoses and components as soon as possible to help keep moisture and contaminates out of the system.

Yes, prior to charging the system, a vacuum will need to be pulled on the system, but under certain circumstances you might not get all the moisture out. Also, if any CA oil residue that might enter the system might cause problems later on.

Auto systems contain a desicant to assist in moisture removal, if there is excess moisture in the system, the desicant will fail and additional problems will result. Any moisture left in the system will freeze and cause a system failure.

The two major enemies of an AC system is moisture & contamination.

As for hoses, you can test them, however, under operation they are subjected to extreme conditions (heat and high pressure). The high side hose pressure could be north of 300 psi. An old hose may fail at any time, even if it was just tested. BTW, if you do have a high side hose failure, it will make a mess. The refrigerant carries oil with it & besides loosing the charge, oil will spray all over the engine compartment.

I am not trying to start something, just sharing some thoughts from someone who has worked on AC & refrigeration systems for sometime.

Regards,

Dennis

[Tom L.]

Re: '69 AC Compressor

An additional method of leak detection has been used for many years. Pressurize the system with any availible gas, nitrogen is preferred because it is inert and does not easily absorb moisture, and apply soap bubbles to all fittings. There are job specific formula's for this purpose but a mix of mild soap and water or windex will do well. If under pressure there are no bubbles to the fittings or seals there are likely no leaks, just be careful and observant. Some of the smallest leaks are easiestly located this way and it is very accurate.