how much $ to flushc a/c & convert r-12 to r-134a?
06-26-2005, 04:08 PM
#31
Burning Brakes
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Thanks, Jim. I drive a lot of long trips in weather like we are having now. I have ester. How do you feel about its ability to take the punishment of the compressor cycling on and off at freeway-speed rpms for hours at a time? My system is working great right now, but I would like to obviously minimize wear on the compressor; should I consider sucking it dry and going to PAG?
- Tony
- Tony
06-26-2005, 10:19 PM
#32
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Hey Tony,
Perhaps you were lucky, but Bad Things Can and Do Happen when you do a sloppy conversion.
When I bought my first 944, the PO had just had the conversion done... paid full price for it too, so as far as he knew, it was a proper "complete" conversion, no short cuts.
Only problem was, the guy who did do the conversion took the shortcut, didn't replace the parts he was supposed to, and *bang* compressor dead within 6 months (more like three if I remember correctly). I had to get it done again, properly this time, and had no further issues until the car was sold.
So you can think about it like "compressor roulette". These stories aren't made up. It's just that they are worst case scenarios, and although it is possible you might get lucky saving a few bucks on a shortcut conversion, where the "bad things" never manifest themselves, most reputable shops wouldn't even bother taking the chance. It's just bad business. Why would you risk a seriously aggrieved customer if all you are doing is saving _the customer_ a few bucks? OTOH, unfortunately there are the shops that will take the chance if it saves _the shop_ a few bucks, so beware, and shop around if you are getting the conversion done.
If you want to do a shortcut conversion to save a few a bucks, at least make sure the dollars that are saved end up in your pocket. And factor in the possibility that all the bad nighttime stories might actually come true...
-Mark
Perhaps you were lucky, but Bad Things Can and Do Happen when you do a sloppy conversion.
When I bought my first 944, the PO had just had the conversion done... paid full price for it too, so as far as he knew, it was a proper "complete" conversion, no short cuts.
Only problem was, the guy who did do the conversion took the shortcut, didn't replace the parts he was supposed to, and *bang* compressor dead within 6 months (more like three if I remember correctly). I had to get it done again, properly this time, and had no further issues until the car was sold.
So you can think about it like "compressor roulette". These stories aren't made up. It's just that they are worst case scenarios, and although it is possible you might get lucky saving a few bucks on a shortcut conversion, where the "bad things" never manifest themselves, most reputable shops wouldn't even bother taking the chance. It's just bad business. Why would you risk a seriously aggrieved customer if all you are doing is saving _the customer_ a few bucks? OTOH, unfortunately there are the shops that will take the chance if it saves _the shop_ a few bucks, so beware, and shop around if you are getting the conversion done.
If you want to do a shortcut conversion to save a few a bucks, at least make sure the dollars that are saved end up in your pocket. And factor in the possibility that all the bad nighttime stories might actually come true...
-Mark
06-30-2005, 02:01 PM
#33
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I just converted to 134a.
Bought a set of used R-12 gauges (Snap On for 40 bucks), cut the old connectors off, and replaced them with parts from a cheap refill kit (Low and Fill) or conversion adapter (high)
Bought a venturi vacuum pump at Harbor Freight- ten bucks on sale. Loud but functions reasonably well. You need a fairly large compressor to run one.
Bought dryer, adapter fittings, Freon, and some kind of "booster" (helps?) locally. Used low viscosity PAG oil as recommended for Nippondenso compressor.
How'd it go? Great. Air is cold. Filled to around 30 psi low, 225 high. A few "lessons learned:"
If you use a 134a/oil pressurized can, fill it first. You need to liquid fill (can is upside down) to get the oil in.
The Harbor Freight vacuum pump is loud and takes quite a bit of air. The vacuum fitting is R-12 size, not 134a so make sure you have a hose that fits.
Keep the 134a can in hot water or filling takes forever.
It seems all low side R-12 fittins are the same but there are several types of high sid fittings. On my 944, both used the same AN style fitting (same as HF vacuum pump). Ended up buying three differend high side adapters and none of them fit. I left the high side non-adapted which was a blessing since I needed the hose for the vaccum pump. Later, I figured out that one of the high side adapters had the correct thread but was "too deep" to fit my car. I put the plastic cap on the adaper and used a hacksaw to cut of the bottom apron. Now it fits fine. This can be addes later because it is just a sleeve- you don't have to remove the schrader valve.
Total cost? around $150 including the gauges and a few "extra" parts.
Hope this helps,
Bill
Bought a set of used R-12 gauges (Snap On for 40 bucks), cut the old connectors off, and replaced them with parts from a cheap refill kit (Low and Fill) or conversion adapter (high)
Bought a venturi vacuum pump at Harbor Freight- ten bucks on sale. Loud but functions reasonably well. You need a fairly large compressor to run one.
Bought dryer, adapter fittings, Freon, and some kind of "booster" (helps?) locally. Used low viscosity PAG oil as recommended for Nippondenso compressor.
How'd it go? Great. Air is cold. Filled to around 30 psi low, 225 high. A few "lessons learned:"
If you use a 134a/oil pressurized can, fill it first. You need to liquid fill (can is upside down) to get the oil in.
The Harbor Freight vacuum pump is loud and takes quite a bit of air. The vacuum fitting is R-12 size, not 134a so make sure you have a hose that fits.
Keep the 134a can in hot water or filling takes forever.
It seems all low side R-12 fittins are the same but there are several types of high sid fittings. On my 944, both used the same AN style fitting (same as HF vacuum pump). Ended up buying three differend high side adapters and none of them fit. I left the high side non-adapted which was a blessing since I needed the hose for the vaccum pump. Later, I figured out that one of the high side adapters had the correct thread but was "too deep" to fit my car. I put the plastic cap on the adaper and used a hacksaw to cut of the bottom apron. Now it fits fine. This can be addes later because it is just a sleeve- you don't have to remove the schrader valve.
Total cost? around $150 including the gauges and a few "extra" parts.
Hope this helps,
Bill
07-01-2005, 01:45 AM
#34
Race Car
The A/C on these cars makes me mad....
My G/F's parents bought a 86 nissan 300ZX about a year ago. The thing had been sitting forever. Motor is excellent, needs clutch, paint work, good cleaning, etc. Low mileage, so it did lots of sitting. I hopped in it to move it the other day, and just for s*** and giggles, I pushed the A/C button, and to my amazement, I got almost instant ice cold air. Still had the original R12 charge in it from when it was built... (we know the original owners) Still works as good as when the car was new. And yet, here we are spending hundreds and hundreds of dollars trying to make our A/C work. Really, what's so different?....
I'm tempted to make my own hoses, buy a generic condensor (perhaps from a 300ZX!!!), and some generic compressor, maybe a sanden, and build some kind of kit, make everything standardized, easy-to-find fittings, normal sized hoses, etc. Maybe Porsche over-did it just a little bit, and it just keeps blowing up...
Gah, did I say the A/C on these cars makes me mad?!
My G/F's parents bought a 86 nissan 300ZX about a year ago. The thing had been sitting forever. Motor is excellent, needs clutch, paint work, good cleaning, etc. Low mileage, so it did lots of sitting. I hopped in it to move it the other day, and just for s*** and giggles, I pushed the A/C button, and to my amazement, I got almost instant ice cold air. Still had the original R12 charge in it from when it was built... (we know the original owners) Still works as good as when the car was new. And yet, here we are spending hundreds and hundreds of dollars trying to make our A/C work. Really, what's so different?....
I'm tempted to make my own hoses, buy a generic condensor (perhaps from a 300ZX!!!), and some generic compressor, maybe a sanden, and build some kind of kit, make everything standardized, easy-to-find fittings, normal sized hoses, etc. Maybe Porsche over-did it just a little bit, and it just keeps blowing up...
Gah, did I say the A/C on these cars makes me mad?!
08-09-2005, 05:33 PM
#35
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quick questions:
1) when you evac the system do you use the same inlet as you do when you fill the system?
2) when you evac the system the pump evac the freon and the old oil at the same time?
3) how do you add the new oil to the system?
4) I've been told that my condensor is leaking, how or where are the condensor seals located?
1) when you evac the system do you use the same inlet as you do when you fill the system?
2) when you evac the system the pump evac the freon and the old oil at the same time?
3) how do you add the new oil to the system?
4) I've been told that my condensor is leaking, how or where are the condensor seals located?
08-09-2005, 06:40 PM
#36
Hey Man
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I just converted the BMW to 134a about a month ago. The system pressure was low on both sides. Here's what I did. Rather than assume everything needed replacement (dryer, hoses, etc) I did a flush and ran it for a few minutes. I put a venturi type vac pump (Harbor Freight) on and pulled a 26 hg for 40 minutes. Reconnected the manifold and determined it would hold vac for at least 30 minutes. I bought one of those conversion kits on sale for $25 that come with the oil, can tap, fill fitting adaptors, and 36 oz. of 134a. It took about 28 oz of coolant and has been blowing @42-46 deg. at the vent ever since, even in hot weather. The only drawback to the 134a conversion is it's less efficient at idle or with low air flow over the condensor. For $25 I wasn't going to waste my remaining stock of R-12.
Paying $400 to convert to 134a is a ripoff unless all your seals and hoses were replaced.
Paying $400 to convert to 134a is a ripoff unless all your seals and hoses were replaced.
08-09-2005, 07:02 PM
#37
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Originally Posted by KuHL 951
I just converted the BMW to 134a about a month ago. The system pressure was low on both sides. Here's what I did. Rather than assume everything needed replacement (dryer, hoses, etc) I did a flush and ran it for a few minutes.
08-09-2005, 11:39 PM
#38
Hey Man
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'Flush' is probably the wrong term, it wasn't a true flush like pulling the compressor, flooding it with solvent, and rocking it back and forth to get the old oil out. I figured most of anything in the system was old oil with no residual refrigerant. I had an almost full can of 134a left over from another car and drained the can just to get some flow moving and to move the old oil through the system, pressures changed a little bit but no real cooling but the compressor kicked on at about 3/4 of the can. I just let this run about 5 minutes to circulate and then evacuated it all through the vac pump, no recovery (go ahead arrest me). A paper towel on the vac pump exhaust showed some clean oil but not much else, no gunk. I never broke seal anywhere and it held a good vacuum so I gave it a shot. The kit I used (Quest) provided a PAG oil compatible with any remaining mineral oil and had a mild sealingr additive.
When I bought the car the PO had just replaced the drier and one hose at the condensor due to a section of fan blade that broke off and damaged the hose so I figured it was free of any R-12 by that time. He never got around to re-charging the system.
If it makes it through the Summer I'll be happy as that was my only intent at the time...as in quick fix, it's 105 deg. and I was dying. I'm not advocating everyone try this but it's still putting out good cold air with no freeze up yet. If it starts to fade after a few months I'll add another charge for a few bucks. During the Winter I'll address any problems or leaks that might develop if needed. I only have about 8 cans of R-12 left and wanted to keep that for the 951 as it's starting to drop off in efficiency after 2 years.
When I bought the car the PO had just replaced the drier and one hose at the condensor due to a section of fan blade that broke off and damaged the hose so I figured it was free of any R-12 by that time. He never got around to re-charging the system.
If it makes it through the Summer I'll be happy as that was my only intent at the time...as in quick fix, it's 105 deg. and I was dying. I'm not advocating everyone try this but it's still putting out good cold air with no freeze up yet. If it starts to fade after a few months I'll add another charge for a few bucks. During the Winter I'll address any problems or leaks that might develop if needed. I only have about 8 cans of R-12 left and wanted to keep that for the 951 as it's starting to drop off in efficiency after 2 years.
