News: - The #1 resource for our W116! Established 2004

Main Menu

450SEL AC cooling issue

Started by bnunes39, 07 June 2024, 11:56 AM


Hi, I have got 450 SEL , the AC cooling is very weak,I had replaced the compressor with a used unit, the low and high pressure are within tolerance, gas level ok , but if driven during the day with outside temperatures at around 41°C , there is no cooling felt, the refrigerant used is R134, as the originally used R12 no longer available, if any ideas please advice.
Thank you.


Not to burst your bubble too much but most older German cars are not exactly known for their stellar AC performance. In actual fact a lot of cars sold in Germany back in the day did not even come with AC.  Not sure if they saw this as a luxury or maybe it did not get hot enough in Germany back then but I'm sure now with summers boiling Europe they have changed their tune...

All this to say in the UAE with 41+C ambient you are asking too much of the system I'm afraid.
1977 450 SEL 6.9 - Astralsilber


R134a does not cool as well as R12.  People use "Envirosafe" which is essentially propane/butane which cools much better.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'21 E450 Cabrio