A/C recommendations for the MB vehicles - Page 21 - PeachParts Mercedes-Benz Forum

Air&Road · #**301** 11-30-2012, 03:15 PM

Quote:

Originally Posted by SuperCow

Im going to convert my airco to R134a
How much gas does it needs?

I bought a new sticker @ the dealer:

It states 0,95KG (950 grams)
I have a 190D 2.5
I believe the R12 amount was 1KG (1000 grams)

Isn't there a 80% rule? how about that?
My airco will be filled with a profession machine, does the shop even need to know the amount of R134?

I'm a little confused/worried about your post. You bought the sticker. Is it FOR SURE correct for your vehicle? If your car was originally R12 and you have no way of getting R12 and MUST use 134a, don't start with 80%. Start with about 60% and work up SLOWLY. I have had conversions work optimally with as little as 65% of the specified R12 volume in R134a. The least amount of 134a you can get it to work with is the best.

DON'T let the high side pressure run away. It is best if you can place a LARGE high volume fan in front of the condensor while charging and let pressures stabilize for five minutes before adding refrigerant beyond the 60% level.

Hope this helps.

SuperCow · #**302** 11-30-2012, 03:30 PM

Quote:

Originally Posted by Air&Road

I'm a little confused/worried about your post. You bought the sticker. Is it FOR SURE correct for your vehicle? If your car was originally R12 and you have no way of getting R12 and MUST use 134a, don't start with 80%. Start with about 60% and work up SLOWLY. I have had conversions work optimally with as little as 65% of the specified R12 volume in R134a. The least amount of 134a you can get it to work with is the best.

DON'T let the high side pressure run away. It is best if you can place a LARGE high volume fan in front of the condensor while charging and let pressures stabilize for five minutes before adding refrigerant beyond the 60% level.

Hope this helps.

I am not sure.
The W201 model doesn't have a R134 sticker in EPC
But however the R12 sticker number, is the same as of a W124 model.
And the W124 model does have a R134a sticker, so i ordered that sticker.
Thats why im also confused, and i don't know much about airco's

Air&Road · #**303** 11-30-2012, 03:37 PM

I would suggest that you do whatever research is necessary to find the specified R12 volume and work from that number. That said, in the case of a 134a conversion, it might not be that big of a deal anyway. Charging an R12 system with 134a is a mixture of rolling dice and black magic.

Start with a very low volume and work up SLOWLY.

Is it impossible for you to obtain and use R12? What have you done to prepare for the 134a conversion?

SuperCow · #**304** 11-30-2012, 03:43 PM

I just typed a small story about it. It sums it up.
http://www.peachparts.com/shopforum/diesel-discussion/329858-w201-2-5d-condenser-help-needed.html

scroll few posts down.

SuperCow · #**305** 12-01-2012, 06:45 AM

@Air&Road

On a dutch mercedes forum, a member converted to R134A with a detailed picture followup.

He has a 1986 W124 260E
They put 1080 grams of R134A in it

Het ombouwen van een Airco systeem naar R-134a

vstech · #**306** 04-13-2013, 06:36 AM

I figured I'd bump this thread to the top for the season.
enjoy!

MS Fowler · #**307** 04-13-2013, 06:51 AM

Thanks.
A/C is on my list after the paint and axles.

leathermang · #**308** 06-07-2013, 10:23 PM

Quote:

Originally Posted by SpecialDelivery

..... how the Sandens are supposedly so much more durable than the r4's. .....

The R4's do not have any oil sump. ALL the lubrication depends on proper system conditions which will move the PROPER oil around the system using the refrigerant...

The Sanden does have an oil sump.... so it is much more forgiving about less than perfect topside conditions.

Listen to Vstech.... I only posted because you used the word ' supposedly' .. because the actual units are probably equal in durability... it is only that in our old systems it is hard to provide the correct ' support' conditions the R4 needs.

ershelby · #**309** 08-07-2013, 05:07 PM

HELP MY 1999 E-300 TD AC IS NOT COOLING PROPERLY FROM BOTH SIDES OF VENTS, ONE SIDE IS WARM AND THE OTHER IS SLIGHTLY COOL WITH THE TEMP SET AT 61 FOR BOTH.

Whiskeydan · #**310** 08-08-2013, 10:04 AM

Quote:

Originally Posted by ershelby

HELP MY 1999 E-300 TD AC IS NOT COOLING PROPERLY FROM BOTH SIDES OF VENTS, ONE SIDE IS WARM AND THE OTHER IS SLIGHTLY COOL WITH THE TEMP SET AT 61 FOR BOTH.

You could have a stuck 'duo-valve'. I had the same issue as you on my SLK. The duo-valve was sticking on allowing hot coolant to flow on one side.

Simple fix.

big d · #**311** 06-08-2014, 01:00 AM

I bought new compressor,dryer and expansion valve for my 1991 350 SD.What oil and how much I need.What viscosity .I have new Denso compressor.Thank you.

vstech · #**312** 06-08-2014, 09:38 AM

What refrigerant are you using?

big d · #**313** 06-08-2014, 11:14 AM

I will use 134 a.

vstech · #**314** 06-08-2014, 12:39 PM

Then pag150 should be correct. 8oz.

ROLLGUY · #**315** 06-08-2014, 04:39 PM

Quote:

Originally Posted by vstech

Then pag150 should be correct. 8oz.

Is that amount correct if starting from scratch and everything flushed out and no oil in the compressor? In other words, 8oz total? The reason I ask, is that I have been taught that 8oz total oil is correct for these systems. I suggest that the buyers of my Sanden kits add an additional 2oz of oil/dye to the system, as 6oz is in the new compressors. Just trying to learn something here....Rich