rebuild or replace AC compressor

[William F.]

Should I get someone(old air? or who) to rebuild my '67 AC compressor or should I buy a new A6 or find(where) a NOS compressor? This has been batted around in previous posts but with some pros and cons, especially about rebuild work by classic air in FL. and old air in TX. What are some current experiences?
Thanks

[Jim T.]

Re: rebuild or replace AC compressor

Do you need a rebuild or just the front seal/pulley bearing replaced?

[Randy S.]

Re: rebuild or replace AC compressor

William,

I had my 66 A6 compressor rebuilt by Classic Auto Air in Tampa. It leaked from the front seal after about one season. They denied my warranty claim as they said I did not use it enough. I had specifically requested they use the ceramic front seal as recommended by Jack Humphrey and others. Classic also rebuilt the STV valve and the drier.

It leaked again and I finally surrendered and bought a new A6 compressor (metric mounting) and that lasted about a year and now I have some oil leaks at the front seal again. I also got one of those compressor shields which I strongly recommend to prevent compressor oil from being slug up on the hood .

So...I moved from Atlanta to Portland, OR and now I don't need it

Randy

[Peter L.]

Re: rebuild or replace AC compressor

William - Is the compressor you are looking to rebuild or replace the original 67 Corvette A6? If so, I'd keep it for judging but for driving, I think I'd get a new or rebuilt A6 and keep . Pete

[Domenic T.]

Re: rebuild or replace AC compressor

William,
I just finished rebuilding my 67 & 63 A6 compressors. I agree that the ceramic seal is the way to go and they are usually not the reason for the front seal leak. The ceramic seal is sealed by 2 o-rings, 1 o-ring seals the outside to the front cover and is placed in the cover. The other is in the ceramic seal and is replaced at rebuild also. The second o-ring seals the ceramic seal to the rotating shaft. I have yet to find a worn ceramic seal surface. The ceramic seal is usually broken if it is not removed properly. I guess what I am saying is that you rebuild the ceramic seal.
I also find the 6 cast iron rings unworn. The end gap on a new ring in a new cylinder is .008 and the ones I just rebuilt were .010. That's about what it takes for a ring to wear in. There are only 2 roller/needle bearings and 2 thrust washers on the shaft and your done.
I have contacted rebuild shops and they say they replace everything but somehow can't find rings and ceramic seals to sell me. I was able to buy the replacment lip seal that seals directly to the turning shaft. It still uses the o-ring to seal it to the front cover but I won't use it till I run out of ceramic seals.
I usually test the compressor for leaks by pressurizing it with air by bolting a valve and guage to the rear ports and make sure it holds pressure for at least 1 hour.
I think that a lot of rebuild shops cut corners or do not replace every thing as they say. If they did all the parts would be in their shop.

DOM

[William F.]

Re: rebuild or replace AC compressor

Here's my problem. Original AC wouldn't blow colder than 72 degrees.Mechanic pulled down system found it to be 1 lb. low;added 1 lb. of real R12. Blows 60-64 degrees-still not where it's supposed to be-in 40's. Low pressure is 60-70; high pressure side is 250. Mechanic says this points to compressor. Compressor does not throw oil.Do those of you with AC knowledge think it's the compressor? If so what do I do-get it rebuilt-lots of bad threads about rebuilds, or buy a new one-what kind, where -want it as original as possible but COLD?
Thanks

[Larry M.]

Re: rebuild or replace AC compressor

Here's my problem. Original AC wouldn't blow colder than 72 degrees.Mechanic pulled down system found it to be 1 lb. low;added 1 lb. of real R12. Blows 60-64 degrees-still not where it's supposed to be-in 40's. Low pressure is 60-70; high pressure side is 250. Mechanic says this points to compressor. Compressor does not throw oil.Do those of you with AC knowledge think it's the compressor? If so what do I do-get it rebuilt-lots of bad threads about rebuilds, or buy a new one-what kind, where -want it as original as possible but COLD?
Thanks

Based on your suction and discharge pressures, I would suspect a stuck POA valve. My car had the same problem, and is now much better after I corrected the POA.

I did this by injecting 1 ounce of refrigerant oil under pressure SLOWLY through the POA. Valve went "ping" and started working.....suction pressure dropped immediately to 30 psig.

Larry

[Mike G.]

Low side pressure looks way high

My understanding is the low side pressure should be 30 psi or so.

How old is your expansion valve? Over-feeding of the expansion valve will cause high pressure at the evaporator outlet and degraded cooling.

If you do end up replacing your A6, I would recommend a new one and definitely add the pulley shield.

But then WTHDIK?

[Domenic T.]

Re: rebuild or replace AC compressor

Hey did I hear some one say you can get the old stock valves rebuilt?
If so where can I send them?

DOM

[Larry M.]

Re: rebuild or replace AC compressor

Hey did I hear some one say you can get the old stock valves rebuilt?
If so where can I send them?

DOM

STV and POA valves can be rebuilt. Classic Auto Air in Florida or Old Air Products in Texas.

Larry

[Randy C.]

Re: rebuild or replace AC compressor

I had my original compressor and dryer rebuilt by the outfit in Texas back in 2003. It still works great and I have my original compressor with the original tag intact.

Randy C.

[Randy C.]

Re: rebuild or replace AC compressor

I forgot to add that I switched from R12 to R134 as well. No problems, but I don't drive the car that much - maybe 400 miles/year.

Randy C.

[William G.]

Re: rebuild or replace AC compressor

Where can you buy a pully shield for the compressor
Thanks Bill

[Jim T.]

Re: rebuild or replace AC compressor

Where can you buy a pully shield for the compressor
Thanks Bill

Bill it is pretty easy to build one. I made an alumimum shield to go on my 70's compressor. I just took two pieces of thin steel and used them as braces to attach some aluminum flashing with rivets. Attached the two pieces of steel to the compressor using the compressors bolts. Made a 90 degree bend in each piece of thin steel and drilled one hole in each for the bolt hole and two additional smaller holes in each brace to rivet the aluminum. I cut the aluminum flashing long and wide enough to do the job. After it was made I rounded the corners and painted it black before permantly installing it. Been using it for many years with no failure.

[Larry M.]

Re: rebuild or replace AC compressor

Where can you buy a pully shield for the compressor
Thanks Bill

There is a guy in Ohio who is making them. They fit fine on C3 and some C2 cars. Some C2 owners report slight underhood rubbing.

I can provide his contact info if you want. PM me.

Larry