Post by HardRocker on Nov 25, 2008 9:22:47 GMT -5
Replacing your auto A/C Compressor:
Here's a great 'step-by-step' or 'how to' guide to replace your auto A/C compressor.
If you're not doing the work yourself, this information will provide you a much better
understand what the auto service shop is trying to explain
Potentially one of the most costly auto A/C repairs is when you have to replace the
A/C compressor. If you're facing that situation now, it's really important that you
understand all the steps that must be followed in order to do the job properly and get
warranty on your replacement compressor. Keep in mind that the 'steps' we talk about
apply to either new or remanufactured compressors, so there is no difference. You will
also find this information of interest if you're having the work completed by a service
shop (or if you're shopping for a service shop). We'll try to eliminate all the technical
terms to make it easier to understand.
What's really important to understand before you start is that the A/C system is just
that... it's a system! That means it's only as good as the weakest link. It also means
that all the components in the system must work together.
To start, let's have a look at some of the components you should really pay attention
to when you're replacing the A/C compressor. They are:
1) the condenser
2) the accumulator or receive drier
3) refrigerant or compressor oil
4) orifice tube or expansion valve (also called a TXV)
5) hose or line assemblies
6) Before you finish, you must flush the A/C system.
You should also give serious consideration to having an in-line filter installed. (More
about that later) and you may still have to retrofit the A/C system too!
Let's start by understanding what happens when the A/C compressor fails and how it
effects the different parts of the system. We will detail the functions of these various
parts and also explain how a blown or seized A/C compressor can effect them. That
way you'll have a real good understanding of how to go about the replacement of the
compressor or be able to better understand what the service shop may be trying to
explain. Remember, we're going to keep the technical jargon out so it's going to be
easy to follow, ok?
To start, remember that the A/C system is a sealed system. When a compressor fails
(usually because of the lack of oil flow to the compressor) the internal parts of the
compressor 'break up' and are pushed throughout several parts of the system. This
contaminates the system and those parts. Before replacing the compressor, several
other A/C parts have to be checked or changed. Here's why.
The Condenser:
The A/C condenser performs pretty much the same function as an engine radiator, but
the condenser cools the refrigerant (or freon) in the auto A/C system. Typically, the
A/C condenser should be flushed to remove any debris. The flushing of the system will
remove contaminated compressor oil and debris scattered throughout the system.
In more current vehicle applications using high efficiency
condensers, you should understand that they may not
be able to be flushed. Why? The passages are simply too
small and much of the debris gets lodged into the tube
openings. In short, it's just impossible to remove all the
debris from these condensers designs. The photo on the
left shows a 'cut away' cross section of a typical high
efficiency A/C condenser. You can see for yourself that
the tube openings are extremely small.
SERVICE Required: Depending on the actual design of
the A/C condenser, it may have to be replaced. If it can
be flushed, it's best to use approved flushing agents that
evaporate quickly and do not leave any residue in the
A/C system. The ability to flush a condenser has to be
considered on a case by case basis.
The Accumulator or Receiver Drier:
Accumulators and Received Driers are not
interchangeable, but they perform the same functions.
This component is in the A/C system to
1) trap, remove and hold moisture
2) filter particles or debris
3) also acts as a reservoir for compressor oil and
refrigerant
Typically, the accumulators are located on the LOW
pressure side of the system. Receiver driers are almost
always on the HIGH pressure side, usually in the liquid
line that runs between the condenser and evaporator.
It's important to remember that one of the main functions of the accumulator or drier
is to absorb moisture from the A/C system. Therefore they include a desiccant
material. Desiccants are typically made from silica gel, and because of their affinity for
water, they make great drying agents. Additionally, accumulators and driers have
filter screens to trap any debris. After a compressor failure, these filter screens
can easily get plugged with debris. KEEP IN MIND.. some of the components that flow
refrigerant through the system work with openings of less than .050" (fifty
thousandths of an inch). It takes LESS THAN 1/10 of A TEASthingy OF DEBRIS to plug
these components and cause a failure.
SERVICE Required: Typically, the desiccants have been proven to become saturated
after three to four years of service. Once saturated, they can no longer absorb
moisture. Additionally, there is no way to check the filter screens for contamination. It
is very common for the debris from the compressor failure to contaminate driers
because the debris is carried throughout the system. Therefore, as a standard
practice, accumulators or receiver driers should be replaced whenever you are
replacing the A/C compressor. Consider that it's much the same as an oil filter on you
engine. You change the oil; you change the oil filter. Like any filter, there is a 'fixed'
capacity for how much debris and contamination any filter can hold. Additionally, if the
accumulator or drier is not replaced, you probably are going to 'void' your compressor warranty.
Here's a great 'step-by-step' or 'how to' guide to replace your auto A/C compressor.
If you're not doing the work yourself, this information will provide you a much better
understand what the auto service shop is trying to explain
Potentially one of the most costly auto A/C repairs is when you have to replace the
A/C compressor. If you're facing that situation now, it's really important that you
understand all the steps that must be followed in order to do the job properly and get
warranty on your replacement compressor. Keep in mind that the 'steps' we talk about
apply to either new or remanufactured compressors, so there is no difference. You will
also find this information of interest if you're having the work completed by a service
shop (or if you're shopping for a service shop). We'll try to eliminate all the technical
terms to make it easier to understand.
What's really important to understand before you start is that the A/C system is just
that... it's a system! That means it's only as good as the weakest link. It also means
that all the components in the system must work together.
To start, let's have a look at some of the components you should really pay attention
to when you're replacing the A/C compressor. They are:
1) the condenser
2) the accumulator or receive drier
3) refrigerant or compressor oil
4) orifice tube or expansion valve (also called a TXV)
5) hose or line assemblies
6) Before you finish, you must flush the A/C system.
You should also give serious consideration to having an in-line filter installed. (More
about that later) and you may still have to retrofit the A/C system too!
Let's start by understanding what happens when the A/C compressor fails and how it
effects the different parts of the system. We will detail the functions of these various
parts and also explain how a blown or seized A/C compressor can effect them. That
way you'll have a real good understanding of how to go about the replacement of the
compressor or be able to better understand what the service shop may be trying to
explain. Remember, we're going to keep the technical jargon out so it's going to be
easy to follow, ok?
To start, remember that the A/C system is a sealed system. When a compressor fails
(usually because of the lack of oil flow to the compressor) the internal parts of the
compressor 'break up' and are pushed throughout several parts of the system. This
contaminates the system and those parts. Before replacing the compressor, several
other A/C parts have to be checked or changed. Here's why.
The Condenser:
The A/C condenser performs pretty much the same function as an engine radiator, but
the condenser cools the refrigerant (or freon) in the auto A/C system. Typically, the
A/C condenser should be flushed to remove any debris. The flushing of the system will
remove contaminated compressor oil and debris scattered throughout the system.
In more current vehicle applications using high efficiency
condensers, you should understand that they may not
be able to be flushed. Why? The passages are simply too
small and much of the debris gets lodged into the tube
openings. In short, it's just impossible to remove all the
debris from these condensers designs. The photo on the
left shows a 'cut away' cross section of a typical high
efficiency A/C condenser. You can see for yourself that
the tube openings are extremely small.
SERVICE Required: Depending on the actual design of
the A/C condenser, it may have to be replaced. If it can
be flushed, it's best to use approved flushing agents that
evaporate quickly and do not leave any residue in the
A/C system. The ability to flush a condenser has to be
considered on a case by case basis.
The Accumulator or Receiver Drier:
Accumulators and Received Driers are not
interchangeable, but they perform the same functions.
This component is in the A/C system to
1) trap, remove and hold moisture
2) filter particles or debris
3) also acts as a reservoir for compressor oil and
refrigerant
Typically, the accumulators are located on the LOW
pressure side of the system. Receiver driers are almost
always on the HIGH pressure side, usually in the liquid
line that runs between the condenser and evaporator.
It's important to remember that one of the main functions of the accumulator or drier
is to absorb moisture from the A/C system. Therefore they include a desiccant
material. Desiccants are typically made from silica gel, and because of their affinity for
water, they make great drying agents. Additionally, accumulators and driers have
filter screens to trap any debris. After a compressor failure, these filter screens
can easily get plugged with debris. KEEP IN MIND.. some of the components that flow
refrigerant through the system work with openings of less than .050" (fifty
thousandths of an inch). It takes LESS THAN 1/10 of A TEASthingy OF DEBRIS to plug
these components and cause a failure.
SERVICE Required: Typically, the desiccants have been proven to become saturated
after three to four years of service. Once saturated, they can no longer absorb
moisture. Additionally, there is no way to check the filter screens for contamination. It
is very common for the debris from the compressor failure to contaminate driers
because the debris is carried throughout the system. Therefore, as a standard
practice, accumulators or receiver driers should be replaced whenever you are
replacing the A/C compressor. Consider that it's much the same as an oil filter on you
engine. You change the oil; you change the oil filter. Like any filter, there is a 'fixed'
capacity for how much debris and contamination any filter can hold. Additionally, if the
accumulator or drier is not replaced, you probably are going to 'void' your compressor warranty.
HardRocker 
