Sagging rear O/S Airspring/bag

[MrW212]

Hi All,
My first posting. I have a 2010 W212 estate and last February I had to have the driver's side ride/height sensor replaced
and as the o/s bag was sinking over a few days and the car being 12 years old I asked the mechanic to replace both bags
with non oem German replacements. After a few days the rear left was still dropping so the distribution valve was replaced
as the soapy water spray showed up no leaks. No joy, same issue so both supply lines and the one from the compressor were all
replaced but no cure. After months of moaning the mechanic replaced the bag and that sorted the sagging for 3 weeks.
Another bag was fitted and after a month the left rear started to sag again. Another mechanic has it in his place for the last
fortnight and he tells me he can't find the leak and suspects the compressor. The n/s also drops a little but I reckon it is
the left side pulling it down !! Is the distribution valve switched off when the car is switched off. ? Any ideas as I am running
out of options.

 

[MrW212]

Hi All,
My first posting. I have a 2010 W212 estate and last February I had to have the driver's side ride/height sensor replaced
and as the o/s bag was sinking over a few days and the car being 12 years old I asked the mechanic to replace both bags
with non oem German replacements. After a few days the rear left was still dropping so the distribution valve was replaced
as the soapy water spray showed up no leaks. No joy, same issue so both supply lines and the one from the compressor were all
replaced but no cure. After months of moaning the mechanic replaced the bag and that sorted the sagging for 3 weeks.
Another bag was fitted and after a month the left rear started to sag again. Another mechanic has it in his place for the last
fortnight and he tells me he can't find the leak and suspects the compressor. The n/s also drops a little but I reckon it is
the left side pulling it down !! Is the distribution valve switched off when the car is switched off. ? Any ideas as I am running
out of options.

Update!!
The mechanic just phoned to say he found the source of the leak. Soapy water didn't highlight any leaks but as a last resort he removed the distribution valve and dunked it in a bucket of water and bubbles emitted from the base of the valve, the bit that sits on the chassis. First mechanic said he replaced it!!!
New part on its way from MB spares so should be 100% in a day or two.