SkylinesSuck

1975 Cutlass Salon w/350. I have had a slow a/c leak for a while and I think I've finally nailed it down, although it's not so slow now. I can actually hear it leaking a bit when the car is off. It appears as though its coming from the back side where the main body of the compressor bolts to what I can only describe as a backing plate. It would be the right hand side of this picture right around half way between the top and the bottom:

[IMG]https://classicoldsmobile.com/forums/4.jpg4.jpg

I can see that's where the dye is coming out, and when I run my finger over the crack, seam, I can hear the sound change. I'm thinking of just buying a remaned compressor from autozone (free shipping to APO addresses overseas) but I was just curious if there was an easier/cheaper fix before I plunked down $300. Thanks!

Also, which compressor should I get? When I type in my car's info at autozone, 6 different compressors come up. Some look long (like mine), some look short, and some say R12, while others say R12/R134a compatible. Any advice?

Lady72nRob71

Use some soapy water to pinpoint the leak.
If between the compressor and the hose fittings (manifolds) then there are some big round rubber seals in between that may be shot.

An auto AC shop should have those.
Did tightening the hose backing plate bolt help any? If it is too tight, the plate may flex and the manifolds get held on more at the edges. See if loosening a tad helps or makes it worse.

Now if yu are referring that the leak is beween the compressor shell and its back end, then it might be candidate for rebuild or replace. Just avoid the 200 refurbished in mexico units often found in local parts stores.

MDchanic

What Rob said.

The hose connections are on the back, so if you've got an identifiable leak there, they're the most likely culprits.
Also bear in mind that a quiet hiss inside the system is normal after turning it off, as the pressures equalize.

If you do need to open and reseal the system, I doubt you'll find R12 within Japanese territory, but you're not that far from Vietnam and Thailand, and I bet you could find some there (probably sold in a jam jar ).

- Eric

Junkman

It the main body seal is where the leak is occurring, there is no amount of tightening that is going to fix that problem. With the high cost of buying R-12 refrigerant, I would be inclined to find someone there that is familiar with air conditioning, and has the proper tools to both check for leaks and to service the unit. If the compressor is functional, then it might just need a new body seal. One thing to keep in mind is that the car is 35 years old, and that all the "O" ring seals are prone to failure at that point. If the compressor needs to be removed for servicing, you might as well also replace the rest of the "O" rings at this point. When freon leaks, it also carries off with it the lubricating oil in the system. For this reason, when the compressor is removed for service, the oil in the compressor reservoir will be drained and measured. The service manual has instructions for how much to add back based on what you remove. You will then need to have to have the entire system evacuated to remove all traces of air, and should replace the receiver / dryer. I have cheated in the past by evacuating the system for 72 hours, and not replaced the receiver / dryer. Many people say that this is a bad practice, but for me, it has worked, and was done more because of the fact that a replacement wasn't available at the time. I would also recommend that you not use any "sealer" in the system, since I have never heard a positive statement that they actually work.
Last year, I purchased a rebuilt compressor for a 1966 Cadillac, and it cost a little over $200 with a $10 core charge. I don't believe that the price has changed drastically since then. The R6 air conditioning compressor has been used for over 20 years, and even though they all look the same, there are many variations of the units. One change was made in the 1970's, where they changed from using SAE bolts to Metric bolts, and varied the mounting pattern slightly. I learned this when I tried to use a 1976 compressor on a 1975 car. The 1975 & 1976 bracketry looked identical, but the mounting holes were located differently. For this reason, I almost always keep the core rather than turning it in for the small core value. If you have problems in the future, you still will have the original unit for comparison or rebuilding.

SkylinesSuck

Thanks for the input guys! It's for sure not coming out of the fittings. It's coming from the seam between the backing plate and the main body. If I get under the car and reach up to the bottom/side of the compressor and run my finger over that seam, I can hear the hissing change. I also used a UV light and can see where the dye is coming out exactly. Here's a little "better" pic :-)

4-1.jpg

I tried tightening the backing plate bolts, but I could only get the one nearest the leak to turn ever so slightly because the fitting going into the back. I tightened the bolt going to them just for good measure as well to no avail.

Why should I avoid the autozone remans? I understand the overall lack of attention to detail, but i really don't have a lot of other options open to me. I'm already running R134a BTW, although R12 is probably slightly easier to get here than in the states. Autozone does free shipping here and that thing is heavy, so it really makes me want to go with them. The core charge is a non-issue since it would cost more to mail anything back than I would get.

I was considering taking it off/apart just to see if there was some kind of seal I could replace between the body and the backing plate. Is there a servicable seal in there? Are the O-rings for the fittings a weird special size or anything?

MDchanic

I wouldn't worry about the AutoZone parts - they should work, and they seem right for your situation.
I honestly don't know how to be sure you're ordering the right one out of a field of identical units, but I have found that sometimes there are telling details about capacity, country of origin, etc. semi-hidden in all the mumbo-jumbo. Also, sometimes you can google part numbers, etc. and find other manufacturer's or seller's pages that have more info.

Finally, I believe you can change that rear plate without special tools (to do the front you need to get the clutch and bearing off), and you should be able to order a compressor rebuild kit that contains the needed seals and just reseal it, then pull a vacuum and fill 'ER up with 134. There is an A/C sealant designed for O-rings called "Nylog" (if I recall), which you might want to use as well.

So you might want to order the seals, try to fix it, and then order the whole compressor if you can't.

Good luck!

- Eric

SkylinesSuck

I'm looking at the re-manned pumps on autozone.com and there are two kinds. One type looks like what I have and says it's got a new clutch with an "A6" pump. There are two versions of that. The $150 one that says R12, and the $320 one that says R12/R134a.



The other is shorter and uses and "R4" compressor. There is a $200 one that says it's R12/R134a compatible. A different one of the same type says "New with clutch With R4 compressor. Compressor may differ in appearance from OE. Please refer to installation kit provided"


http://www.autozone.com/autozone/par...89_14236_3513_


Has anybody used this shorter looking one before? It says it's aluminum instead of cast iron. I'm assuming they provide the stuff to make it bolt right up, but I think I would need new hard lines, right?



Also, where can I find an accumulator/dryer? I can't find one on any parts site. Unfortunately, having working a/c here is about as necessary as having headlights at night.


One last question. How can I tell if my system has been "recalibrated" for R134a? There is a very old sticker saying it was converted, but I get one of those stickers with the cans of 134a I buy, so I'm not real sure. It doesn't blow super cold now (when it is charged all the way up.)

MDchanic

I don't know the details of converting from the A6 to the newer R4 compressors, but I believe that the A6s have more capacity, and I'm 90% sure the R4s have metric fittings.

As for the accumulator, try searching "receiver/dryer."
That's what they were called - the newer ones were called accumulators.

Finally, if your system won't blow cold, it probably wasn't converted right.
I doubt there's much you could do about it over there - your entire system probably has to come apart, be flushed, and be reassembled with proper O-rings, a better condenser, and a recalibrated POA (or be put back to R12).
There will be a variety of opinions on this, but I would say that if you're somewhere where you NEED A/C, 134 won't blow cold enough without some big changes.

- Eric

Junkman

Just saw this Google ad at the bottom of the page......

SkylinesSuck

I'm reading a lot about a "VIR update" and found something on ebay with a compressor and CIR update package:

http://cgi.ebay.com/ebaymotors/73-74-75-76-77-CUTLASS-C-Compressor-VIR-Package-/180486407989?pt=Motors_Car_Truck_Parts_Accessories &fits=Make%3AOldsmobile|Year%3A1975&hash=item2a05d 40735

Something I should look into? Is there a big difference in cooling efficiency? At $400 it's spendy, but if it fixes my leak and makes the system blow colder more efficiently with R134a, it might be worth it. I'm still trying to figure out if that silver cylinder pictured is the dryer or not.

*Edit, I just noticed that is a stock VIR they are including in that kit, not an "eliminator." I'm going to give them a call Monday night (my time) and talk their ears off asking them what I should do :-)

MDchanic

VIR was an alternative cooling arrangement, with a bunch of different parts, that was used on the mid-seventies. It stands for Valve In Receiver, and I believe it was a version of the POA system, just with the valve assemblies included in a single block on top of the receiver, which was attached to the firewall air box, instead of to the condenser.
It's sort of a precursor to the next configuration that's still in use, except (I believe) it doesn't cycle the compressor clutch.
If you don't have it already, I don't think it's relevant to your system.
I'm not sure whether it worked any better.

- Eric

SkylinesSuck

LOL, that auto correct is killing you!

So are there pre-calibrated parts I can buy and swap in to make my system more R134 friendly?

66ninetyeightls

Unless you replace all the parts with R134a specific components a converted R12 system will never blow as cold with R134a in it.

Doesn't really matter either way since R134a will go the route of R12 within the next 5 years.

SkylinesSuck

Do you have a list and location where I can order these parts from? Remember, everything needs to get shipped to japan. Just getting a replacement compressor and slapping it on is starting to seem like the only cost effective option.

SkylinesSuck

This is all I can find, but I was expecting some kind of metal cylinder.

http://www.autozone.com/autozone/par...9059_146689_0_



I just ordered this A6 compressor seal kit from ebay:

http://cgi.ebay.com/ebaymotors/ws/eB...m=290558553068

I'm going to give a shot at replacing the seals before I drop the coin on a new compressor.

MDchanic

This is the receiver / dryer they list for my car ('73 88). $16.00



If yours has the receiver up front attached to the condenser, it may be yours too.

Here is a seal set for your compressor - ten bucks - not bad.


You can definitely buy recalibrated POA valves, and new receivers and 134 condensers, but I don't have an immediate suggestion as to where, as I'm not an expert in this, and also I'm not sure what fits your car, as the '73-'76 series is a bit of an orphan, or, as they say nowadays, is no longer supported .

- Eric