When I acquired this car (98 E320) 4 years ago it had 66,000 km, very little use and the a/c was marginal, I presume it had seldom use and the system deteriorated.
I had noticed leaks of oil from the compressor and I suspect that would also leak freon. I do not believe it had dye.
If any hoses are leaking I should be able to detect that when I vacuum the system, should I not?
It appears to me I will have to flush the system before I continue.
I have read some condensers cannot be flushed and must be replaced, is that the case here?
Thanks
DougQ

 

The compressor very well may be the problem but with such extensive work to replace all the components, Id want to be sure there are no other areas of failure such as lines, valves. The vacuum will let you know if you cant achieve -27 inch or better but it will not direct you to where the leak is. Dye like shown in the link in the other thread above or possibly a sniffer will find others if any. The only items you can flush are the lines and evap. Condenser can not be flushed.

 

Oil A/C questions 98 E320 - almost ready to get this project finished.

I am replacing the comp (done), rec/dryer, and exp valve on this project.
I have flushed all of the system, and would like confirmation about the amount of oil and where to put it.
After I started this project I needed to drive the car before the A/C was functional, so I added oil to the new comp and installed it.
Obviously the clutch will not be energized as the sensors on the rec/dryer are disconnected and all hose connections covered.
Initially I removed the old comp, tried to drain oil (it had none), I also drained oil from new comp, which had very little.
Consulting a MB chart for the 210, I added 120 cc + 10 cc (rec/dryer) = 130 cc of pag oil to the comp plus a bit of UV dye I had on hand.
The charts are shown here:
https://imgur.com/a/1DZGy4q

So, after flushing the system I believe I have to add an amount of oil equivalent to installing new components.
By my calculations that is an additional 100 cc, if I am correct??
The second chart has an odd bottom line about the comp oil needed to be 20 cc??
When I first added the 130 cc to the comp I put it in the intake port and turned the shaft a few times.
The unit came with rubber plugs and caps which I re-installed.
So where should I add the additional 100 cc of oil?
Also in the intake port?
Or to the rec/dryer or the intake hose?
Is turning the comp by hand a few times sufficient?
I also found this gem on the net from a Denso web site:

Of course this time of year I might not need the a/c but I need to finish this project.
Thanks for any help.


DougQ

 

When I replaced the compressor, I filled the 120cm- spun the shaft. Didn't add the additional.

In my case I did replace the condenser (not sure if you did) so I inserted the amount into the condenser and oil into the separate replaced components respectively-I did the dryer last after everything else was filled and closed off. Added additional for the lines into the components to compensate for lines since I flushed those. I bought a cc syringe and squirted the required amounts into the parts while they were out. It will be difficult to squirt PAG into the evaporator in place due to space. You may need to use a bendable vinyl hose from the syringe into the evaporator.

Replace and lube al O rings. Be sure you add the right amount of refrigerant by weight.

 

Thanks for the reply tall giraffe, I do like your idea of adding the oil to the individual components,
Did you end up with the same total that I have calculated?
That is 230 cc?
DougQ

 

Yes

TG

 

Thanks TG

 

Has anybody run into an issue on when the heater is turned on, there is a major leak of r134a? The ac runs fine during the hot summer months, but as soon as that one day when it gets cooler, the heater turns on, all the r134a leaks out? Do you know what to look for to repair? I refilled with r134a and it’s fine but when heater is on, low in r134a again.

 

Put some dye in it.
When heating doesn't have direct connection with AC system, quite possible weak oring expands in warm weather and shrinks when cold.

 

Finally got my A/C back up and running.
I wish to thank Plutoe, Tall Giraffe and kajtek1 for their input.
As mentioned I have replaced the comp, rec/dryer and exp valve.
That exp valve was a lot of fun, totally buried.
I managed to get the water collector out without taking out any circuit boards.
I flushed all the system and learned not to use rubber hose for that.
I flushed a lot of solvent through the evaporator before realizing I was flushing the rubber hose on the output as it disolved.
I had a little dribble of oil as I was starting to add it to the evaporator input.
So I had to guess the ammount of dribble and put it in the output, where it stayed.
The system held 30 in of HG, over night, so I was confident it would not leak.
Of course the weather is not conducive to testing A/C, but we had a very sunny day that heated up the car and cold air was experienced at all vents.
Hopefully it will be the same next summer, and of course the dehumidifying effect will help during the wet months.
DougQ

 

Congrats! Im sure its a great feeling to get it working. In my case I stripped one of the allen bolts in the exp. which made the journey leading to it all that more fun at the end Also I had to go there twice since I had to replace the evaporator after a failed hope my evaporator was ok.

Im still surprised you actually flushed the condenser.

If you took your time and were thorough, you should have a long lasting system.