evaporator

P38 AC Evaporator Removal &Replacement

Bad Evaporator

Introduction
Diagnosis
Parts Needed
Strategy for Accessing the Evaporator
Dismantling Tips
Re-Assembly
More Information & Related Operations

Introduction
The climate control system in the 4.0/4.6 models is a considerable improvement over that in the Classic, but like any A/C system it will eventually get worn out and develop leaks. Scott Kirn had this happen to his 1995 4.0SE, and the leak appeared to be coming from the evaporator area. Scott kindly submitted the following report on the process of removing and replacing the evaporator, to help others with the same problem.

Photo: Bad evaporator after removal from vehicle

Diagnosis
Scott's AC system was not holding a charge. The last time he had it recharged, his local shop put a leak detector in the refrigerant, that when viewed with a special light, allowed them to see where the refrigerant was leaking. When it ran out again (after two days), the special light was used to find the leak. If you put the light up behind the glove compartment, you could see the leak detector glowing there, right where the evap sensor is mounted in the heater unit. Since there is no reason for Freon to be swirling within the housing on its own, this meant that most likely the evaporator itself was leaking within the housing.

Parts Needed
Scott purchased a used evaporator from Roverland Parts (www.roverlandparts.com) for $150. At the time of this writing, a new evaporator is about $600.

Preferably, you should also replace the 20 wheel liner clips (part# ANR2224) as these plastic items are weakened by removal. I have removed and replaced my wheel liners during other operations and re-used the old clips, but found that the sagging of the old clips caused some rubbing on the wheel liners.

Overall Strategy for Accessing the Evaporator
Unfortunately, the AC evaporator is located within the heater unit, which is located behind the middle of the dash, which can only be accessed by removing the entire dash (or fascia) assembly (see photo below). Some of this process is also outlined on the fascia panel removal page, which describes replacement of the fascia trim panel when it is warped. However, replacing the evaporator requires considerably more dismantling, ending up with everything removed from the front of the interior (see photo below). Scott found the entire operation took him about 12 hours for removal and 10 for reassembly. With the help of Scott's tips and instructions below, your time should be less!

To remove the entire dash, the manual has you backtrack four or five steps before you even get to the evaporator removal. Scott has kindly summarized those steps and put them in their correct order to facilitate searching through the manual. The following major components need to be removed, and in this order:

In removing these components, you have the option to take advantage of access previously hard to reach components, and preemptively replacing them now to ensure many years of trouble-free service. The access you have to these components is nothing short of amazing. Here is a list of components that you may consider replacing during this project:

Dismantling Tips
Scott offers the following illustrations and hints to ease the dismantling process. The descriptions assume a RHD NAS model Range Rover with 2 point SRS; however most of the procedures apply to other models.

I found it easier to remove the side panels by applying a sudden, strong downward force to disengage the sprag clips. This part is pretty durable, so I wouldn’t be concerned breaking anything. The only other note I have here is that on my ’95, I only had one screw securing the selector lever.

First, make sure your wheels are pointed straight ahead. This will allow the bolts to be accessed much easier. Also, I found that removing the wheel well liners here make access much easier. I used a crowbar to remove the wheel well liner clips. You will need to replace these.

Soak the lower universal joint and splines with penetrating oil of some sort to ease in removal. I could not slide the universal joint up the splines as the manual suggested, mostly because I could not get enough leverage to apply the force needed. I ended up moving on to the next step of removing the steering column, which then allowed the intermediate shaft to be removed. If you do move on, I would recommend tying up the intermediate shaft so it doesn’t fall once you remove the steering column.
Steering Column

You will need a small Torx wrench to remove the wiper components. Other than that, this part was pretty straightforward. Make sure you pull the steering column straight out and do not turn the steering wheel. If you haven’t already removed your intermediate shaft, you should hear it drop at this point.
Windscreen Side and Lower Finishers

Again, this part was straightforward. The scariest part was removing the lower windscreen finisher, since it is held in by plastic clips and takes some force to disengage. Get your fingers right next to each clip before pulling upwards and you should be fine (see photo below).

The only discrepancy I found here is that my driver’s side panel had a ground wire going through the grommet, which prevented me from removing the panel altogether. But I found that these panels do not need to be removed, and instead can just be moved aside.

I listed this as a step, but found I didn’t need to remove the motor or linkage at all! Just removing the scuttle side panels gave me the access I needed for the following steps.
Fascia Assembly
Here is the fun part. None of the steps are particularly difficult; there are just a lot of them! Step 22 mentions removing some BeCM multiplugs. You may find the rear multiplug difficult to access. If so, use a Torx wrench to remove or at least tilt the passenger seat. (Hint: you will probably find yourself doing the same for the driver’s seat later on, so you might as well do it now.) You then pull these wiring harnesses out from under the trim molding. Step 27 mentions removing the SRS multiplugs. This is located directly under where the cubby box would be, probably hidden by the carpet (see photo below). There is a weird part on the red connecter that you slide out, which allows the multiplug to be removed from the box.

The SRS crash sensors are located under the air dryer unit and the battery box respectively. Follow the yellow wiring harness to locate them. You then pull these sensors back through the wheel wells and into the cabin. This was not hard at all.

Finally, step 40 mentions removing the 4 tube bolts. I actually had 5 tube bolts, with the 5^th being located directly behind the steering column. I removed it only to find that it wasn’t attached to the fascia at all. I do not know what it attached to.

Step 44 mentions removing the rubber seals from the air intake ducts. This is where the pollen filters were. Just reach inside and unseat the lip of the seals from the fascia, then they pull right out.

After removing the last couple of bolts, the fascia is ready to be removed from the vehicle. I would recommend moving the gearshift lever as far back as it can go to give you room to maneuver the fascia. However, since you have no power to the vehicle, the solenoid interlock will not allow the gearshift to move. You will need to push the interlock mechanism manually with a screwdriver. Check out “Selector Lever Assembly” in the manual on how to do this, but basically you just push aside the piece of metal locking the gearshift in place. I would also recommend removing the bolts securing the drivers seat and tilting it all the way back.

The manual recommends a second person helping you remove the fascia, and I would agree. It is somewhat heavy, but generally very awkward. Pull the fascia away from the windshield so that the 4 bolts clear the holes in body. Then just maneuver the fascia out of the driver’s side door the best you can. Rest it on a table right side up, just as it is in the truck. You should be able to rest it directly on the 4 metal supports. The hard part is over now (see photo below, which is a view of the back of the entire dash once it is remoced from the vehicle).

I found that removing the nuts securing the passenger and driver’s side blower motor allows you to disengage the ductwork much easier. You don’t need to remove the motors, just the nuts so you can move the motors aside. Have someone hold the fascia when you pull the heater unit out. The heater unit is not heavy (see photo below).

Evaporator
The manual tells you how to remove the evaporator housing, but not how to access the evaporator itself. To access the evaporator, you need to remove 2 screws securing the two housing halves together. Then use a screwdriver to pry off the many, many gold clips. Pull the two housing halves apart, and you are staring at the evaporator.

In my case, I could see a lot of leak detector residue on one corner of the evaporator, which must have been the problem (see photo below). I also noticed that my passenger side drain tube was clogged, even though I clear them out regularly from underneath vehicle. My theory is that this caused the water to back up slightly in one corner of the housing, resulting in the evaporator essentially sitting in water more often than it should. This may have caused it to fail prematurely.

Just as the manual says, reassembly consists of reversing your steps. However, I took this opportunity to do a do a few things which may help re-assembly. The first step recommends taping the rubber seals to the blower ducts. I used some weather-stripping adhesive to hold the rubber seals to the lip of the ducts, and then folded the rubber seals inside the duct, using tape to hold it in place (see photo below). I also taped the wiring harness and SRS wiring together and then taped it down on top of the dash to keep it out of the way.

Moving the fascia back inside the vehicle is awkward, but not impossible. A third person would really help in aligning the heater and evaporator pipes through the firewall while the other two people do the lifting. I found that the metal bracing by the steering column kept getting caught when trying to fit the fascia in place, so this is a place to keep an eye on. Once you fit the bolts through the fascia, you are home free.

When replacing the lower windscreen finisher, I found it easiest to snap in one clip, then use a screwdriver or something similar to align all the other plastic clips with their holes before seating the rest of the finisher. This minimizes the amount of bending you need to do to see under the finisher (see photo below).

When refitting the steering column intermediate shaft, I would recommend cleaning the splines which will help in reassembly. Also, I found that I had much better access to the intermediate shaft and the universal joint that connects the shaft to the steering column by accessing it from under the vehicle.

The rest of the reassembly process is pretty straightforward, if not a bit tedious. The manual does help, as long as you follow the steps closely and in order.

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Page revised February 2, 2012