Servicing A/C that has R12
Thread Starter
Burning Brakes
Joined: Jan 2015
Posts: 875
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I was thinking of spraying it clean inside like when you clean a throttle body or something. But don't want to use unsafe products that would damage the compressor or the metal/plates inside.
Probably will pull the orifice first to make sure it's not covered in black metallic slim.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
That depends on the year and I don't know the capacity for your car.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The only thing I've found that works is 409 but I'm afraid the parts will rust if I use that. I don't know what kind of metal the various parts are made of. The pistons look polished and a magnet won't stick to them so they could be aluminum or stainless steel.
I read somewhere that you shouldn't use anything that is chlorinated.
Thread Starter
Burning Brakes
Joined: Jan 2015
Posts: 875
Likes: 76
I've been wondering the same thing. I have a Denso compressor in pieces on my bench. I've tried brake parts cleaner, carb cleaner, denatured alcohol and mineral spirits. None of them dissolves the mineral oil.
The only thing I've found that works is 409 but I'm afraid the parts will rust if I use that. I don't know what kind of metal the various parts are made of. The pistons look polished and a magnet won't stick to them so they could be aluminum or stainless steel.
I read somewhere that you shouldn't use anything that is chlorinated.
The only thing I've found that works is 409 but I'm afraid the parts will rust if I use that. I don't know what kind of metal the various parts are made of. The pistons look polished and a magnet won't stick to them so they could be aluminum or stainless steel.
I read somewhere that you shouldn't use anything that is chlorinated.
I guess at least do a dray wipe down if there is crap inside it. Then when together fill with oil. Turn it over for a while, then dump the oil and repeat.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
Only thing I can find is they say when flushing the A/C to NOT flush the compressor. But can't find anything about if you can use something to clean the inside of the compressor if you have it apart. I watched a video where the guy replacing seals on a 10PA said you have to wear gloves, as the oils on your fingers I guess can damage the plates inside it.
I guess at least do a dray wipe down if there is crap inside it. Then when together fill with oil. Turn it over for a while, then dump the oil and repeat.
I guess at least do a dray wipe down if there is crap inside it. Then when together fill with oil. Turn it over for a while, then dump the oil and repeat.
The 5 case bolts require a new copper gasket that comes in your seal kit, and need to be torqued to the proper value.. this I don't remember.
Thread Starter
Burning Brakes
Joined: Jan 2015
Posts: 875
Likes: 76
you don't have to chemically clean the inside of the compressor, drain it well, and wipe it down.. The only time it is critical to wear latex glove's is when you handle the "Shaft Seal" they are sometimes designed with a "Carbon" wear surface, and are ground perfectly flat for a good sealing surface. The new ester based lubricants act like a degreaser and can easily handle small amounts of mineral oil. Now your Accumulator needs to be replaced if you switch over to 134, it was designed for an R12 system and is not compatible with R134.
The 5 case bolts require a new copper gasket that comes in your seal kit, and need to be torqued to the proper value.. this I don't remember.
The 5 case bolts require a new copper gasket that comes in your seal kit, and need to be torqued to the proper value.. this I don't remember.
Melting Slicks
Joined: Jun 1999
Posts: 2,931
Likes: 127
From: Ashland Alabama
Another day of 38 degrees from the vents and 95 degrees outside cruising down the road with 134a in my r12 system with nothing done but the conversion kit.
$39.95 spent and zero problems.
As for ones done long term.
1984 blazer - 767,000 miles, 6 engines, original transmission. Converted to R134a around 140k miles. Still blows snowballs.
1985 trans am - Over 300k miles. Converted to 134a with the kit around 110k miles. Still works.
1978 Monte Carlo - Converted around 180k miles. Had 290k or so on it when I sold it and was still ice cold.
Ive converted literally 100's of cars and with no major failures from the conversion with just the conversion kit. I still top off cars for people all the time but the ones "leaking" were doing that before the conversion and the owners are to cheap to fix the system right. At least now they are just venting safe 134a in place of the r12 is one way of looking at it.
$39.95 spent and zero problems.
As for ones done long term.
1984 blazer - 767,000 miles, 6 engines, original transmission. Converted to R134a around 140k miles. Still blows snowballs.
1985 trans am - Over 300k miles. Converted to 134a with the kit around 110k miles. Still works.
1978 Monte Carlo - Converted around 180k miles. Had 290k or so on it when I sold it and was still ice cold.
Ive converted literally 100's of cars and with no major failures from the conversion with just the conversion kit. I still top off cars for people all the time but the ones "leaking" were doing that before the conversion and the owners are to cheap to fix the system right. At least now they are just venting safe 134a in place of the r12 is one way of looking at it.
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Thread Starter
Burning Brakes
Joined: Jan 2015
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Anyone had problems converting to R134? i.e. compressor failures?
It would be the best time to convert though since I'd be replacing the seals in the compressor and have to fix the schrader valve leak.
Could install the R134 fittings on the schrader valve, flush out the lines and condenser and evaporator and replace all of the orings and put in a new orifice and accumulator.
I believe you use ester oil for conversions, which I believe is 8oz you put in a flushed system.
I believe the A/C hoses used in 89 are okay to use with R134? I recall reading the type of hoses used in earlier years won't work with R134 because they are more porous. I forget the year though.
It would be the best time to convert though since I'd be replacing the seals in the compressor and have to fix the schrader valve leak.
Could install the R134 fittings on the schrader valve, flush out the lines and condenser and evaporator and replace all of the orings and put in a new orifice and accumulator.
I believe you use ester oil for conversions, which I believe is 8oz you put in a flushed system.
I believe the A/C hoses used in 89 are okay to use with R134? I recall reading the type of hoses used in earlier years won't work with R134 because they are more porous. I forget the year though.
Thread Starter
Burning Brakes
Joined: Jan 2015
Posts: 875
Likes: 76
Also read of people changing the low pressure switch from an R12 (25 PSI) switch to an R134 (22 PSI) switch.
This is an interesting readings:
http://www.misterpeachy.com/VetteStu..._to_Denso.html
http://tech.corvettecentral.com/2008...4-ac-retrofit/
Instructor
Joined: Apr 2003
Posts: 204
Likes: 9
From: Ocean Springs MS
[QUOTE=colter;1589921544]Did you put in a different orifice? I've read of GM R12 to R134 conversions where people change the orifice to a blue Ford orifice instead of the GM white orifice.
Also read of people changing the low pressure switch from an R12 (25 PSI) switch to an R134 (22 PSI) switch.
I used the standard GM replacement orifice from the parts store when I replaced the compressor. I have heard of the Ford orifice swap, but never tried it. Didn't feel like having to go back in there if it didn't work right.
I left the original low pressure switch on the accumulator. I have seen the aftermarket ones with the R134 calibration, but the R12 switches have the same adjustment screw between the terminals, so they can be recalibrated for 134 also. It is possible the R134 switch could give better cooling.
My plan was to leave everything stock, see how it worked, and make changes or adjustments if needed. As it turned out, it seemed to work fine, so I left everything alone. That was 5 or 6 years ago, and it still works.
Also read of people changing the low pressure switch from an R12 (25 PSI) switch to an R134 (22 PSI) switch.
I used the standard GM replacement orifice from the parts store when I replaced the compressor. I have heard of the Ford orifice swap, but never tried it. Didn't feel like having to go back in there if it didn't work right.
I left the original low pressure switch on the accumulator. I have seen the aftermarket ones with the R134 calibration, but the R12 switches have the same adjustment screw between the terminals, so they can be recalibrated for 134 also. It is possible the R134 switch could give better cooling.
My plan was to leave everything stock, see how it worked, and make changes or adjustments if needed. As it turned out, it seemed to work fine, so I left everything alone. That was 5 or 6 years ago, and it still works.
Thread Starter
Burning Brakes
Joined: Jan 2015
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I'll probably just look at converting it to R134 since I'll be tearing it apart anyways. Hopefully the compressor is still good as it's probably be running on low oil. Mine is 89, so I think the hoses are good for R134 as I think they went to barrier hoses in 88.
I'll probably tear it apart to flush it out, put in new orings, dryer, and orifice tube, add oil, and change to R134 fittings. And then take it to a shop to put a vacuum on it and add the R134.
I'll probably tear it apart to flush it out, put in new orings, dryer, and orifice tube, add oil, and change to R134 fittings. And then take it to a shop to put a vacuum on it and add the R134.
Instructor
Joined: Apr 2003
Posts: 204
Likes: 9
From: Ocean Springs MS
That should work. But if you're able to do all that you might as well get a harbor freight vacuum pump for $99 and some Big Lots R134 for $7 a can and charge it yourself. Probably still cost less than paying a shop.
Thread Starter
Burning Brakes
Joined: Jan 2015
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The problem is knowing how to charge it. Been doing some reading on the change over process, but they don't really go into depth in how to charge it up where you don't over charge it or under charge it. Still doing some reading, so may be able to understand it. Was thinking a shop would know how to properly charge it. I know you are supposed to do something like 80% of the R12 charge.
Instructor
Joined: Apr 2003
Posts: 204
Likes: 9
From: Ocean Springs MS
You can do it. Pull a vacuum, dump a whole can in upside down (liquid), start the engine and dump another can in and see how it cools and check the pressure. Usually takes about half another can to get the high side up to around 250 and it should be good.
Thread Starter
Burning Brakes
Joined: Jan 2015
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I'll be getting a tank of R12 and R12 manifold gauges. Looks like you can't really find adapters for the gauges to connect to the 3/8 and 7/16 A/C ports.
May just get R134 manifold adapters, and put R134 quick connect adapters on the A/C lines.
May just get R134 manifold adapters, and put R134 quick connect adapters on the A/C lines.
Race Director
Joined: Mar 2015
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Look on ebay and buy the valve tool remover kit that you remove the valve stems without looseing freon it come with all the connectors and very handy. Mine has paid for itself many times over. I never charge but they are so happy they tip.