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Discussion Starter #1
Hallo after a long time! I need some help with the original air-condition of the ASCONA B. Firstly, does anyone know if I can find an original compressor for that? Does it operate on R12 freon?
Would it be better to fit another compressor "modern" which operates on R134a freon? If yes, from which car does it fit best? I suppose I have to change also the air-condition pipes, correct? Obviously, I will have to make a basis to mount the compressor on the engine, but this is easily solved. However I do not know if it is so easy for the belt.

Thanks in advance for any help!
 

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Idon't know what the B series Ascona had for a a/c compressor, but, it used the old R12 freon. You would benefit from going to a more lightweight/efficeint compressor from Sanden, and switch over to the R134a freon. I don't know if you have to change hoses, but, the evaporator has to be changed (I think), and there's an orifice somewhere in the system that needs to be changed.
Find a local a/c expert and they should be able to answer your questions more thoroughly.
 

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Idon't know what the B series Ascona had for a a/c compressor, but, it used the old R12 freon. You would benefit from going to a more lightweight/efficeint compressor from Sanden, and switch over to the R134a freon. I don't know if you have to change hoses, but, the evaporator has to be changed (I think), and there's an orifice somewhere in the system that needs to be changed.
Find a local a/c expert and they should be able to answer your questions more thoroughly.
I doubt if the evaporator will need changing and never have seen one that did on a conversion. But the dryer-receiver will need to be changed to one with the proper R134A desiccant. In some rare cases the condenser needs to be changed. But very rarely because the original one was borderline in size due to poor engineering. In most cases in an old system, the old hoses can still be used because they have become so saturated with the oil R12 type oil, they don't leak enough of the new R134A to mention. I converted my1963 Ford with factory air conditioning from R12 to R134A and only had to flush out the old lines and compressor with compressed air to blow out all the old oil and then replaced the oil with the R134 type. Replaced the receiver-dryer and recharged with about 7/8th the quantity of the old R12 charge with 134A and it's been working fine for 5 years now with only one can of R134A added last year to make up for the small amount of leakage past the old compressor shaft seal and what little gets through the 46 year old rubber hoses.

Like Gene recommends. Take it to an automotive air conditioner specialist if you don't have the special vacuum pump and r134A gauges and knowlege you will need.
 

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Discussion Starter #4
Thanks guys for the info. As I know the evaporator does not need to be changed, but the hoses do need.
BQS4 what exactly do you mean by the orifice? You mean the "choking valve" (if it is said so)?
Aardvaark what do you mean dryer-receiver? What exactly is this?
Thanks once again.
 

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It's my understanding, there's a metering orifice, or choking valve you call it, somewhere in the system. I don't know if this needs to be changed or made sure it's clear, but, a a/c specialist would know.
 

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Aardvaark what do you mean dryer-receiver? What exactly is this?
Thanks once again.
It's the part that needs to be replaced EVERY TIME the system is opened up for any length of time since it contains a dryer desiccant bag that removers moisture from the system to prevent corrosion to components.

One of either two types are used.
The 'accumulator-dryer' is located in the system between the vehicle interiors evaporator and the compressor suction and stores partially gaseous refrigerant and oil.
Or the 'receiver-dryer' is located after the compressor ahead of the evaporator and stores compressed liquid refrigerant and oil.


If a functioning system is opened up, the dryer of either type should be immediately plugged to prevent any air from entering, and it can then be reused then.
 

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It's my understanding, there's a metering orifice, or choking valve you call it, somewhere in the system. I don't know if this needs to be changed or made sure it's clear, but, a a/c specialist would know.
Some systems use the orifice with an inlet filter, and should be changed when the system is opened up or quits functioning because debris can clog the filter. Other systems use a thermostatic expansion valve instead of the orifice. Sometimes with a filter also, but not always. GM AC systems tend to use the expansion valve type. Many Fords use the orifice type. Just have to look to know or look it up on rockauto.com or other source.
But nothing is for sure. http://www.polarbearinc.com/PBPC/Homepage/Search/EX/EX_Orifice.html
 

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Discussion Starter #9
Thank you very much for your valuable information guys. The AC on the ASCONA B is a factory installed intergrated system.
 

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"The dryer/receiver is located in the system between the vehicle interiors evaporator and the compressor suction to store liquid refrigerant and oil prior to entering the compressor. It is designed to separate droplets of liquid refrigerant and oil from the gaseous refrigerant and oil before entering the compressor suction."



To clarify, actually, the receiver-dryer is not located in the suction line to the compressor. It is located in the high pressure (discharge) part of the system just downstream of the condensor, and it is filled with a liquid-phase freon, not a gaseous phase. It is located here to clean the stream of any trash or moisture before it enters the expansion valve at the evaporator and to serve as a storage well of high pressure liquid freon to feed the expansion valve as it needs it. HTH
 

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"The dryer/receiver is located in the system between the vehicle interiors evaporator and the compressor suction to store liquid refrigerant and oil prior to entering the compressor. It is designed to separate droplets of liquid refrigerant and oil from the gaseous refrigerant and oil before entering the compressor suction."



To clarify, actually, the receiver-dryer is not located in the suction line to the compressor. It is located in the high pressure (discharge) part of the system just downstream of the condensor, and it is filled with a liquid-phase freon, not a gaseous phase. It is located here to clean the stream of any trash or moisture before it enters the expansion valve at the evaporator and to serve as a storage well of high pressure liquid freon to feed the expansion valve as it needs it. HTH
I knew that, doh! I was thinking of an ac accumulator/dryer. Brain hiccup. Accumulators-dryers are on the low side vs a receiver-dryers being on the high side. Both do similar functions and contain a desiccant.
 

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Opeler
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I knew that, doh! I was thinking of an ac accumulator/dryer. Brain hiccup. Accumulators-dryers are on the low side vs a receiver-dryers being on the high side. Both do similar functions and contain a desiccant.
Yes, given your background, I knew that was what you wanted to say, but didn't. Just wanted to clarify it before it got filed away. I'd gloat a little if I hadn't done the same thing myself before.

Bob
 

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A few more diagrams

Here is an example that uses the receiver-dryer.

Bt the way. If you are not aware of him, Anthony Drosos http://www.opelgt.com/forums/members/alpharm.html may be able
to help you find parts or someone who can help you with the ac on your Ascona.
 

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More Opels than sense
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Hallo after a long time! I need some help with the original air-condition of the ASCONA B. Firstly, does anyone know if I can find an original compressor for that? Does it operate on R12 freon?
Would it be better to fit another compressor "modern" which operates on R134a freon? If yes, from which car does it fit best? I suppose I have to change also the air-condition pipes, correct? Obviously, I will have to make a basis to mount the compressor on the engine, but this is easily solved. However I do not know if it is so easy for the belt.

Thanks in advance for any help!
The original compressor is a GM R4 unit - they were fairly common on American cars in their day, but they're getting harder to find now. Your local air conditioning shop may be able to find you one, or you can try an online parts supplier in the US.

Any replacement compressor you get these days will be able to run on R134a.

I've got air conditioning in 3 B-Mantas, one is still running on R12 (and uses a Sanden compressor) but the other two are on R134a (and use GM R4 compressors). All the systems work OK, although the one with the Sanden really needs 1500-2000rpm for the air to get truly cold. The ones with the R4 compressor get cold at idle. Personally, I'd stay with the R4 rather than swapping to a different compressor.

To retrofit to R134a you will need to replace the accumulator at least. I would also recommend replacing the orifice tube (in the evaporator inlet pipe) with a variable orifice (a "VOV"). My local air conditioning shop recommends using ester oil when refilling rather than PAG oil.

I've heard that you need to use barrier-type hoses with R134a, which is what you're probably referring to when you ask about replacing the pipes. On one of my cars has a mix of original Opel hoses and new barrier hoses and I've not seen any leakage yet (and it was last filled 8 years ago), so I'm not convinced that it's a problem.

In the same way, I've also heard that the black O-rings used by Opel may leak with R134a. I have an Opel Monza that's been converted to R134a and it still has some of the black O-rings, but again I've not seen any leakage (after 7 years), so I'm not convinced that's needed either.

The evaporator and condenser will be fine, although I recommend you modify the wiring to bring the condensor fan on when you move the air conditioning lever to the blue star or white star position (i.e. when the A/C is actually on). That will put more air over the condenser and make the air cooler. R134a is less efficient than R12, and this will help restore cool air on really hot days.
Cheers,
Nick
 

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Yes, on 2 of my Mantas I use R4 compressors and R134a. One car has been running like this for 8 years, the other for just 2 years. No problems so far.
 
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