When a failed BMW compressor is replaced by a new BMW a/c compressor, it is so important to have the lubricant
distributed evenly across the BMW air conditioning compressor and the a/c system before engaging the system for the first
If this is overlooked and the BMW air con compressor is engaged immediately after is has been charged with
refrigerant, it may happen that all the oil in the BMW a/c compressor will be pushed out all at once while there
is no oil yet to enter the BMW air conditioning compressor on the other side. This is caused by the fact that it takes some
time for the oil to spread across the system and mix with the refrigerant. Eventually the BMW ac compressor
may be damaged because of a lack of lubrication during the first few minutes of operation.
This will of course be more problematic after the system has been flushed, this will mainly be the
case after the BMW air con compressor has suffered a catastrophic failure with metal particles from the BMW a/c compressor
being spread across the entire system.
A rule of thumb guide when installing a new BMW air con compressor is to manually turn the BMW a/c compressor pulley
to make sure that the oil is distributed through the BMW air con compressor evenly. Experienced engineers will
normally turn the BMW ac compressor 10—15 times to ensure that oil has been pushed around the system.
There is still more to do to prepare the BMW air con compressor, knowing and following the procedure will be of
great importance if a newly installed BMW air conditioning compressor should fail after a short period of time and within
its warranty period. There is no bigger disappointment than having a warranty claim denied because
something as simple as the following procedure has been overlooked.
Generally new BMW a/c compressors are supplied charged with oil, but it is always recommended that you
check this by draining the new BMW air con compressor to check the amount of oil in the BMW air conditioning compressor.
Then once you have removed the old BMW a/c compressor you should do the same again, empty the old BMW ac compressor
of oil to see how much oil was in it and then fill the new BMW air con compressor with the same amount
this is to avoid over charging the system with oil.
1, Open all air louvers at the dash board, 2, Start the engine and let it stabilise at idle speed 3, Set the
blower at maximum speed, 4, Engage the a/c system and operate it continuously for 2 minutes at below
After the two minutes the BMW air con compressor oil will have distributed evenly throughout the a/c system.