Mercedes-Benz Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
79 Posts
Discussion Starter #1
Year: 1988
Model: 260E
Mileage: 124,xxx
Engine: M103

Hello,

I have a 260E that the A/C System has not been working since I owned the car. I converted the Low and High Service Ports to R134A Connectors and hooked it up to an A/C Service Machine (rather someone else did). They provided a vacuum test and determined what I thought was the issue that there is a leak or leaks in the system.

I am wanting to replace all the O-Rings in the system with brand new ones and then clean up the system to re-charge with R134a.

My questions are:

1. Do we have notes anywhere or a walk-through regarding all the O-Ring locations as well as all the steps that are needed to properly convert everything over to properly use again. 2. Do we have a part number or any information as to what kit I would need to purchase that would have all the O-Ring, preferably for our cars, not a generic kit.

Thanks in advance
 

·
Premium Member
2014 G550, 2000 SL500, 1995 E320 Cabriolet, 1980 TR8
Joined
·
1,326 Posts
While replacing the O-rings is laudable, unfortunately a more common source of A/C leaks on a W124 is a rotting evaporator. Before you do the O-rings I would, have someone with a leak detector (sniffer) rule the evaporator out as the cause. It is a long and painful job to replace it so you will have to decide if having A/C is worth it to you if it is leaking.
 

·
Premium Member
Current, 90 300CE, 92 400E (Sold 95 E320,70 250C, 91 190 2.6, 91 420 SEL, 95 300D, 87 TD)
Joined
·
1,744 Posts
Use ..lot of labor. A new evaporator is not that expensive if I remember.

What's a job that cost you a lot in labor.
I did it myself but it wasn't easy. Getting the radiator out is a breeze but everything else is a tight fit very hard to get out a lot of the bolts nuts and screws. I remember having to do a lot of finagling to get it out.
 

·
Registered
89 300E; 00 E320
Joined
·
2,519 Posts
Before you tear your dash out you may want to try a little stop leak and see if you can get enough refrigerant pressure in the system to see if the compressor will work and cool and find out exactly where the air blows at different settings. Maybe you get lucky and if fixes it entirely. And as Flooby suggested you could put some dye in there with the stop leak and refrigerant.

There is a different oil in the compressor for the R12 vs the 134A but some of the over the counter hydro carbon stuff would work with the mineral oil used in R12 and I would probably try that first before putting the 134 in there. Again, just trying to see if the compressor engages and compresses.

So, first find the problem. Maybe it turns out to be the o-rings, maybe the evaporator, maybe the compressor. I had an ac company quote me thousands for an evaporator years ago, it must have been a pin hole because it is still holding vacuum 10 years later. Try the stop leak, dye and hydrocarbon and see if you can get some pressure. Then you can remove or replace the compressor as needed, drain or add the mineral or pag oil and replace the o-rings too if you want. You will want to get a new drier and maybe an expansion valve.

Now as far as the fan goes and the vacuum pods in the dash, they work ok in the default position but direct alot of air toward the windshield. What this is about is that although you are able to get your ac to cool, you may not get the cool directed exactly where you want because the vents are controlled by those vacuum pods and their diaphragm, well they breakdown. And when they do the air flow is directed to the default, which is mostly toward the windshield so you can defrost or de-condensate. It's a safety first thing.
 
1 - 4 of 4 Posts
Top