[jgajito]

1994 E320 W124 Sedan

What type of gas? R134, can I get one of those DIY from Kragen, Pep Boys, Autozone, etc... Recommendations on Do's and Don't?

Anyone ever done this by themselves have a link to a write-up?(DIY)

Forum is flooded with many posts, but too many to sift through.

Thanks in advance!

:thumbsup:

 

[Uboater]

Buy the higher priced bottle of 134 , with a pressure gauge / hose combo . This will determine how much you need to fill it , adding only what is required . Its easy to do .

 

[jgajito]

:thumbsup: Thanks, I saw those and wasn't sure if anyone else has used it before.

 

[GDC]

My '94 E320 uses R134, I would think that all of them do. Topping off is an easy job with the units with a gauge. If you need anything more than a top off, it can get much more difficult.

 

[Jayare]

Take care to not overcharge the system. R134 operates at much higher pressure than R12. Remember, our evap units (at least the older model ones) aren't the best in the world and can sometime costs more to replace than the car is worth.

Good Luck,

Jayar

 

[nalonge]

My '94 E320 uses R134, I would think that all of them do. Topping off is an easy job with the units with a gauge. If you need anything more than a top off, it can get much more difficult.

Do they all use R134, meaning all 124's? What's the easiest way to determine if it's an R12 or R134? My compressor won't engage so I was going to start with something cheap and try and charge the system myself.

Nick

 

[2phast]

1992 and up MB all use R134 (except W201). The pre-mixed oil/R134 cans work well and I have used them for many years. The cans with the gauge are nice but you can purchase the gauge's seperate if you choose.

Although I don't have a write up on this procedure, you can use the instructions that come with the refill kits.

Look at this picture, directly behind the ABS pump is a gold tube with the fitting sticking out of it, at the end of the fitting is a black plastic cap. This is the low side filler point for your AC on a M119 motor. The M104 and M103 motors should have a filler point in a similar location.

 

[Uboater]

Do they all use R134, meaning all 124's? What's the easiest way to determine if it's an R12 or R134? My compressor won't engage so I was going to start with something cheap and try and charge the system myself.

Nick
***************************************************

Nick as rule all gases have a different valve -fitting . 134 hose / cylinder only will attach to a 134 system . Even a converted 12 system will have POS adapter fittings and a sticker to show the tech what its charged with .

The gauged bottle lets you see the pressure , without guess work or buying an expensive hose manifold . If your flat -Zero pressure , its better to have a shop pull a vacuum and find the leak .

 

[Arnie2]

Static gas pressure depends on ambient temperature, so filling a system according to pressure is not the best way, especially as you cannot be sure how much oil is in the system already and how much more you might be adding. The ratio of oil to refrigerant is very important for the system to operate efficiently and for the oil to be able to lubricate the compressor.

All systems have a green sticker specifying how much refrigerant the system should contain by weight. You can see from the sticker that the tolerances are pretty tight. As an example, it might say something like 934g +/- 10 g. This is the only proper way of charging the system: to drain it and re-fill (using the same gas if necessary) it by weight. (If doing a complete refill, the charging cylinder can be placed on an accurate scale to determine how much gas has been transferred.)

 

[augapfel]

2phast, is your red 500 the one that was on ebay late last year or early this year. It was being sold out of Utah, I think. Can't be too many red ones around.

 

[nalonge]

Which One

I picked up a can of R134 with the guage. The connector on the gauge does not seem to fit on my fitting so I'm thinking I have the R12. Here's a pic...

 

[nalonge]

Ok, so I got the conversion kit and some R134 with the guage. I fitted the adapter and started filling the system. The compressor engaged (which is good news I think) but still no cold air. Do you think I need to add more R134, or is something wrong??

 

[edfreeman]

Ok, so I got the conversion kit and some R134 with the guage. I fitted the adapter and started filling the system. The compressor engaged (which is good news I think) but still no cold air. Do you think I need to add more R134, or is something wrong??

You did a conversion yourself? I can't see it too well, but it looked like you still had R-12, ie - there was no adapter fitting installed. I'm not sure what all they do to convert one to 134, but if you didn't do those things, I'd stop putting 134 in until you're sure you've covered all the bases.

 

[nalonge]

I thought it was a s simple as putting the adapters on. I didn't put in anymore R134 but does anyone know what else I need to do to convert this system?

 

[jephey]

I used a refill kit with guage, before I refilled the pressure was at 0, and I filled it up to the "Green" area of the guage, which I believe was around 40. The air worked great... but, in about 72 hours the air conditioner stopped working again and is presumably empty.

An insulated hose under the airbag/foot area of the passenger's side has a bright green colored gunk/liquid on it that I don't remember seeing, I guess this hose could be the leak?

 

[2phast]

Let me guess, your 1992 has a build date in 91? These early production 92 models still had R12, it wasn't till later in the build that they converted them to R134. There should be a sticker on the radiator support that says whether or not you have R12 or R134.

 

[Uboater]

jephey

If your system had zero pressure ,there is a good chance it has moist air in the system and need repair and /or a vacuum leak check. The hose maybe the main leak , but it could have a shot compressor too .

I would never attempt a charge / refill with zero system pressure , if the clutch wont engage BEFORE THE REFILL its most likely too low.

Any moisture will freeze in the expansion valve stopping the system . Pulling a vacuum and finding leaks is the most important first step with an empty system.

The quick and dirty compressor check , with some refrigerant in the system should have a hot & cold hose at the compressor while running on high .In some cases you can power the clutch with jumpers to charge the system. You can exceed the system pressure doing this ,its only to get the pressure up so the Min. pressure switch will engage.

Use a water hose to cool the condenser ( radiator ), while your working on it to keep the pressures low.

 

[jgajito]

Thanks for the help, it was all pretty simple, thanks!:thumbsup: