Can I run R134a in my 1982 300SD if I get a newer condenser? - Page 3 - PeachParts Mercedes-Benz Forum

lorainfurniture · #31 06-29-2013, 06:10 PM

Quote:

Originally Posted by Squiggle Dog

I live in Phoenix, Arizona (it is 119F today), and this is my only running vehicle, so I want the coldest air conditioning possible (any at this point would be nice). If keeping everything stock and using R12 will be colder than modernizing all of the parts and then installed R134a, I will stick with R12. I just don't want to be stuck with needing a recharge and R12 being scarce and extremely expensive, or illegal to use.

It is NOT scarce, (look on ebay) Not expensive ($30 a pound if you pay retail) and is by no means illegal.

tbomachines · #32 06-29-2013, 06:10 PM

Hey Jooseppi I think that fan was swapped for a higher cfm unit. I know the white car had a circular shroud non-stock fan, I can't remember if I replaced that with the stock unit when I swapped over but I think we kept the aftermarket one. If the circular one is in there then you can cross that off the list.

Beastie · #33 06-29-2013, 08:58 PM

I may be wrong but I thought I read that the 85 SD had a different comdenser ?
Alan

Codifex Maximus · #34 06-29-2013, 09:26 PM

Quote:

Originally Posted by Squiggle Dog

I live in Phoenix, Arizona (it is 119F today), and this is my only running vehicle, so I want the coldest air conditioning possible (any at this point would be nice). If keeping everything stock and using R12 will be colder than modernizing all of the parts and then installed R134a, I will stick with R12. I just don't want to be stuck with needing a recharge and R12 being scarce and extremely expensive, or illegal to use.

With AC, if your system still has the R12 rated parts, you would be better continuing to use R12 in that kind of heat. Just make sure the system is clean and leak tested/vacuum holding is good.

You can always go to R134 later and absorb the cost after your R12 components fail.

Making components of the system more efficient never hurts but can be very costly.

I live in Texas and plan to go the complete rebuild route:
Sanden compressor, new hoses, parallel flow condenser, 2nd Gen Fan, new Receiver Drier, clean out the evaporator, replace the expansion valve and switch, check/replace the drain and temperature tube/sensor in the dash. It's gonna be costly and time consuming but I gotta do it. I plan to drive this wagon for a very long time.

TheDon · #35 06-29-2013, 10:15 PM

Quote:

Originally Posted by JamesDean

I concur. My 190E (ES12A)is cooler than my 300D (134A).

ES-12A is NOT meant to be charged into a vacuum evidently.
They make a variant that IS to be charged into a vacuum and they claim it will output cooler vent temps.

Eventually Im going to buy a vacuum pump and give the "industrial" Es-12A a shot.

So what, vac the system and then release the vac after drying out the lines? I'm doing an es12 install this week.

vstech · #36 06-29-2013, 11:01 PM

what I've read about es12, you do not HAVE to evacuate, but evacuation is wise for best performance. air does not condense... water will not affect the refrigerant, but it can affect the oil.

Squiggle Dog · #37 06-29-2013, 11:22 PM

My R12 components are all bad, anyway. I was thinking it would be wiser to install all R134a compatible parts (new condenser, compressor, hoses, etc) and then use R134a. But, if even using entirely new technology parts with R134a doesn't cool as well as the old technology using R12, then I guess there is no point in converting since it seems R12 will be available forever.

ROLLGUY · #38 06-29-2013, 11:41 PM

Quote:

Originally Posted by Squiggle Dog

My R12 components are all bad, anyway. I was thinking it would be wiser to install all R134a compatible parts (new condenser, compressor, hoses, etc) and then use R134a. But, if even using entirely new technology parts with R134a doesn't cool as well as the old technology using R12, then I guess there is no point in converting since it seems R12 will be available forever.

You will be amazed at how much better a Sanden does even with everything else stock. A PF condenser will give even better results. If you can get R12, it would be better regardless of what equipment is used. It is also my experience (and that of others), that maximum air flow across the condenser is needed when running 134a. I like to have the aux fan running whenever the compressor is engaged, and not rely on the thermal switch (it comes on too late, and takes longer to cool things down)....Rich

vstech · #39 06-29-2013, 11:44 PM

there is a thread on here where a member redesigned his ac to use an orifice tube, and it has massive air flow, and it's COLD!!! and it uses 134a, so it's possible, the stock system is designed for cooling... not superchilling the vehicle.

ROLLGUY · #40 06-29-2013, 11:56 PM

Quote:

Originally Posted by vstech

there is a thread on here where a member redesigned his ac to use an orifice tube, and it has massive air flow, and it's COLD!!! and it uses 134a, so it's possible, the stock system is designed for cooling... not superchilling the vehicle.

That is great, but not everyone can do that. With the 100+ degree temps we are having this weekend here in the So Cal desert, my 240 is very comfortable inside after a few minutes of driving (it takes a few minutes to cool the hot cab after sitting in the sun). I am just saying that a Sanden upgrade is well worth the $ and effort, and will give much better cooling than the R4 ever thought of giving. A Sanden with R12 would be even better....Rich

Doktor Bert · #41 06-30-2013, 04:42 PM

Quote:

Originally Posted by vstech

there is a thread on here where a member redesigned his ac to use an orifice tube, and it has massive air flow, and it's COLD!!! and it uses 134a, so it's possible, the stock system is designed for cooling... not superchilling the vehicle.

I have made an aluminum block that replaces the expansion valve on some vehicles that contains a drilled orifice and a port for a cycling switch.

Nowadays I think you can simply purchase the blocks online to convert to a CCOT system...FWIW

Doktor Bert · #42 06-30-2013, 04:44 PM

Quote:

Originally Posted by ROLLGUY

I am just saying that a Sanden upgrade is well worth the $ and effort, and will give much better cooling than the R4 ever thought of giving. A Sanden with R12 would be even better....Rich

Hmmmm....I get 33-35°F i the vent on my W116 in the SoCal desert with R-12 and the same R4 I have been using since the 1990's.

Although smoother running and requiring less HP to operate than the R4, I doubt the Sanden would make the system any colder....FWIW

upshift · #43 06-30-2013, 06:06 PM

I have converted at least five Mercedes to R-134a from R-12, and frankly I think the notion that R-134 fails to sufficiently cool the car is way overblown.

I blow out the oil, replace the o-rings, replace the receiver drier, pull a deep vacuum on the system for a few hours to boil off contaminants, then charge the system with Ester oil and fill with 80% of the R-12 capacity.

I have tested the air vent temperature of the cars after doing this and many of them will come awfully close to freezing temps - yes, even with an R4 compressor.

Several of these conversions are now over three years old, used almost daily, with zero issues. I see no reason to spend a fortune changing hoses, compressors, condensers, etc until something breaks.

ROLLGUY · #44 06-30-2013, 06:19 PM

Quote:

Originally Posted by upshift

I have converted at least five Mercedes to R-134a from R-12, and frankly I think the notion that R-134 fails to sufficiently cool the car is way overblown.

I blow out the oil, replace the o-rings, replace the receiver drier, pull a deep vacuum on the system for a few hours to boil off contaminants, then charge the system with Ester oil and fill with 80% of the R-12 capacity.

I have tested the air vent temperature of the cars after doing this and many of them will come awfully close to freezing temps - yes, even with an R4 compressor.

Several of these conversions are now over three years old, used almost daily, with zero issues. I see no reason to spend a fortune changing hoses, compressors, condensers, etc until something breaks.

Agreed. Except that my experience with many R4's has been horrible, and that is why I developed the Sanden retrofit kit. I have not used R12 in any Sandenized 'Benz yet. Your methods described above are EXACTLY the way I have done my conversions, with the only exception being the changing of hoses to work with the updated compressor. A few have used a PF condenser, but only because the factory unit was bad (no sense replacing it with the same old technology).....Rich

ohiomike · #45 06-30-2013, 06:50 PM

I used "Enviro Safe" that absolutely mixes with both R12 and 134a..I put it in over 6 years ago and it will freeze you right out of the car. You have to buy the adapter for 134a if my memorey is correct. Great stuff.