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Replacing the Air Conditioner Condenser
 
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Pelican Technical Article:

Replacing the Air Conditioner Condenser

Mike Holloway

Time:

30 minutes30 mins

Tab:

$210 to $856

Talent:

**

Tools:

Phillips head screwdriver, 10mm socket wrench, 10mm open ended wrench, universal socket

Applicable Models:

Mercedes-Benz R107 (1972-89)

Parts Required:

AC condenser, may also require sensors

Hot Tip:

Remove any component to provide more room

Performance Gain:

A properly cooled car

Complementary Modification:

Replace the existing refrigerant with R-134A

Before you do any work on your car it is important that you wear safety glasses, work gloves and dispose of all fluids in a safe manner. Coolant is poisonous and should be treated as such. Animals and small children have been known to die from ingesting coolant. If you have to jack up your car, make sure to use jack stands and chock your wheels as well as applying the parking brake. Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability. Always wear eye and hand protection and disconnect the battery.

The air conditioner not only cools the airflow but it also reduces the humidity. The air conditioner works by a system of 4 processes: Evaporation, Condensation, Compression, and Expansion.

So here is how the whole process works in your car:

Step 1) The AC gets turned on.

Step 2) The compressor pumps the refrigerant (R-134A) to the condenser. The R-134A is under high pressure. A belt driven by the crankshaft powers the compressor.

Step 3) The condenser converts the gas into liquid because of the high pressures. This also generates heat during the process. The condenser looks like a radiator and actually acts like one. The circulation and the fins of the condenser help cool the R-134A.

Step 4) The liquefied R0134A moves to the receiver/drier accumulator, which is a small reservoir. This removes any water that may have leaked in. When there is moisture present it can form ice that reduces flow or worse, it can create damage to the compressor.

Step 5) After the liquefied R-134A leaves the receiver, it goes through an expansion valve. This valve opens up the volume for the liquefied R-134A to become gaseous.

Step 6) The gaseous R-134A is pumped to the evaporator. The evaporator looks very similar to the condenser or the radiator. The evaporator is where the real cooling takes place. As the cold, low pressure R-134A flows into the evaporator, it vaporizes even more so and pulls heat from the air circulating throughout the cabin. A fan pushes air over the fins of the evaporator so that cold air is circulated throughout the car.

Step 7) the process continues because the R-134A flows back to the compressor to start the refrigeration cycle all over again. The expansion valve regulates the degree of chilliness.

A word of note before you start: The AC system is charged with a refrigerant that is both dangerous and illegal to discharge into the atmosphere. If you are going to be working on the system make sure you have the refrigerant properly evacuated and reused or disposed of. Discharging, evacuating, and charging the AC system must be performed by properly trained and certified technicians, in a facility that has a recovery and recycling system that adheres to the SAE standards.

There are a couple important facts about the refrigerant that you should be aware of. First it is really cold. If it contacts your skin it will give you severe ice burns. Another consideration is that if the refrigerant comes in contact with an open flame it becomes very toxic and even a small whiff can be fatal. Do not apply any heat to the system of any hardware located near the AC system. It is best to check and see if there is any refrigerant in the system. This will be the first thing covered. You will need to remove the drive belt, shroud and radiator before beginning this job. Please see our article radiator removal for further assistance. For additional information on the AC system, please see our articles on: Replacing the AC Evaporator and Replacing the AC Receiver/Drier Accumulator and Replacing the AC Belt.

Before you start, check the system for refrigerant. This is done by pressing in the Schrader valve and seeing if any refrigerant comes out. There are two Schrader valves on the AC lines. These valves are almost identical to the valves used on tires. Using a flathead screwdriver, depress the valve to see if the system has been evacuated. The refrigerant is going to be very cold so make sure you are wearing gloves and eye protection. Just depress the Schrader valve quickly to see if there is any refrigerant in the system. If there is, always make sure you have the refrigerant properly and professionally evacuated. Most places will give you a credit or store your refrigerant until you can place it back in the system later. They may also charge a disposal fee. You will have to have them charge the empty system.

You will need to remove the front grille.

After the grille has been removed, the fan is in plain sight.
Figure 1

After the grille has been removed, the fan is in plain sight. The fan has to be removed in order to get to the condenser.

Using a Phillips Head screwdriver, loosen and remove the bracket located in the center.
Figure 2

Using a Phillips Head screwdriver, loosen and remove the bracket located in the center.

Using a 10mm socket, loosen the remove the bolts holding the cross beams.
Figure 3

Using a 10mm socket, loosen the remove the bolts holding the cross beams.

The electrical lines may have a cable tie holding them to the cross beams.
Figure 4

The electrical lines may have a cable tie holding them to the cross beams. These will have to be cut and replaced.

There will be a bolt under the condenser core, which has to be loosened and removed.
Figure 5

There will be a bolt under the condenser core, which has to be loosened and removed. A 10mm wrench must be used.

It is also possible to use the opened end of the wrench as well.
Figure 6

It is also possible to use the opened end of the wrench as well.

A 10mm socket can be used to loosen the bolts holding the AC condenser.
Figure 7

A 10mm socket can be used to loosen the bolts holding the AC condenser. You may choose to leave the bolts on at the top and remove the bottom ones and shift the AC condenser towards the engine bay. This will allow room to lift the fan assembly forward.

The grille under the front end must be removed as well.
Figure 8

The grille under the front end must be removed as well. This is done with a Phillips head screwdriver.

10Mmm bolts located under the AC condenser will also have to be removed.
Figure 9

10Mmm bolts located under the AC condenser will also have to be removed. All the bolts are the same size, which will reduce the amount of bolt labeling required.

The bolts at the top of the AC condenser only have to be loosened allowing the AC condenser to swing back.
Figure 10

The bolts at the top of the AC condenser only have to be loosened allowing the AC condenser to swing back. Be careful not to stress the AC lines.

There is a bolt behind the cross members that has to be removed as well.
Figure 11

There is a bolt behind the cross members that has to be removed as well. Use a 10mm wrench.

There is a 10mm bolt behind the AC condenser unit that also has to be removed.
Figure 12

There is a 10mm bolt behind the AC condenser unit that also has to be removed. Use a 10mm socket to loosen and remove.

The AC condenser can now swing backwards to allow room to remove the fan assembly.
Figure 13

The AC condenser can now swing backwards to allow room to remove the fan assembly.

There is an electrical lead that has to be unplugged.
Figure 14

There is an electrical lead that has to be unplugged.

After the lead has been unplugged, the fan is ready to be removed.
Figure 15

After the lead has been unplugged, the fan is ready to be removed.

After the fan has been removed, it is now ready to be replaced.
Figure 16

After the fan has been removed, it is now ready to be replaced. 

Remove the (2) two 10mm bolts holding the top of the evaporator to the frame.
Figure 17

Remove the (2) two 10mm bolts holding the top of the condenser to the frame.

The condenser is now free to be replaced.
Figure 18

The condenser is now free to be replaced. Installation is the opposite of removal.


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Comments and Suggestions:
Bob Comments: A lot of duplicate listings in the index
September 1, 2016
  Followup from the Pelican Staff: Thanks for the additional info. We appreciate it. I will have it updated.
- Nick at Pelican Parts
 
Bob Comments: in the index listing this is for the evaporator not the condenser
September 1, 2016
  Followup from the Pelican Staff: Thanks for the catching that. We appreciate it. I will have it updated. - Nick at Pelican Parts  
Banyan Comments: is this article about evaporator or condenser? this is very confusing...
May 30, 2015
  Followup from the Pelican Staff: Looks like a condenser to me. Thanks for catching that, I will have the tech article updated. - Nick at Pelican Parts  

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Page last updated: Fri 12/9/2016 02:47:36 AM