| Let's
remember that most of the A/C compressors that
Mercedes Benz have used do not carry their own
onboard oil supply. The refrigerant oil is delivered
throughout the system via the refrigerant. |
|
| Just
as you would not run your engine without oil
people attempt to run the air conditioning compressors
without oil. How does this happen? Underneath
the hood of your car is a pretty hostile environment
subject to all kind of heat, cold, and vibration.
Over time refrigerant may be lost through the
various seals and out the front of the compressor.
Since the refrigerant carries the oil it stands
to reason that when you lose refrigerant you
lose the oil at the same time. If you fail to
replace the oil when you add new refrigerant
you might as well log on and start pricing a
new compressor. If you are not doing the job
yourself, do not assume that refrigerant oil
has been added. You must ask and make sure.
It will be cold when you pick it up but not
for long. |
| |
| Preventive
maintenance goes a long way. When you open the
hood do a visual inspection of your Mercedes
air conditioning system. Check your air conditioning
hoses, Mercedes compressor, and Mercedes condenser
for signs of leaks, that is oil residue at any
of the joints or on the parts. Failure to repair
the problem may damage or destroy the compressor
since you are losing the oil that lubricates
the moving parts of the air conditioning system. |
| |
| If
your Mercedes air conditioner is not working
properly do not use it until you can check it
out. This may prevent further damage. Remember
that your compressor turns on when you turn
on the defroster too so do not assume that it
can wait till spring to have it repaired.
|
| |
| Oh
No, My compressor is bad! |
| Ok,
now you realize your Mercedes A/C compressor
is kaput so let's fix it right the first time.
No use crying over spilled milk. The key now
is to get you cool again and make sure you do
not have any more problems. |
| |
| Do
not just bolt up another compressor without
trying to analyze why this one went bad. Check
for signs of leaks and make sure the auxiliary
fan works. If the compressor clutch is white
or shows signs of being subjected to extreme
heat you can figure the compressor was intermittently
locking up. This is due to lack of lubrication
or internal breakage or both. Whatever the reason,
shrapnel from the compressor was introduced
into the system. Failures to remove this shrapnel
will grenade your new Mercedes compressor. This
is not covered under the warranty. |
| |
| You
must change the receiver drier when changing
your new compressor. Just consider the receiver
drier the oil filter for your air conditioning
system. Some of that metal will be found there.
By the way, if you do not change the drier the
manufacturer will not warranty the compressor.
|
| |
| Another
item that we recommend changing at this time
is the expansion valve. These for the most part
are easy to change and very inexpensive. The
expansion valve allows the refrigerant to be
sprayed on the evaporator. The orifices are
very small and easily clogged by debris. You
are not going to clean the valve so just change
it now so you can assure yourself that when
you install the new components described above
the system will blow really cold air. It is
a shame to redo the whole recharge over a part
that costs approx $25.00 for many applications.
|
| |
| One
last thought. If you are going to use a refrigerant
other than what came in your vehicle check to
make sure the refrigerant temperature switch
you have installed on your drier is the right
one for the refrigerant you are using. R134a
uses a different switch than R12. The switch
with the pigtail is the refrigerant temperature
switch. These are temperature switches not pressure
switches. Different refrigerants operate at
different temperatures so double check your
application. |
| |
| Ps:
It has been our experience that when the clutch
is bad on your Mercedes compressor, it failed
because of the scenario above. Don't waste your
money just replacing the clutch. Change the
compressor. We can argue that point till the
cows come home but that is our opinion and we
are sticking to it. We have seen to many people
try it and lose. Why take a chance, besides
when you see the price of a clutch versus the
price of a compressor with a new clutch it becomes
a no brainier. |
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