Trail Maintenance: 5th Gen 4Runner A/C Refresh

Trail Maintenance: 5th Gen 4Runner AC Refresh

A/C Smelling a little bit funky? Time to kill some microbes: How to Refresh the AC on a 5th Gen 4Runner

Summer is here and most of us are probably running our A/C. Over time this weird funky smell develops and sometimes this smell lingers and never leaves! This usually means that there are some mold, bacteria, fungi, and micro-organisms (for simplicity I’m just going to refer to these as microbes) growing within the A/C evaporator housing causing the funky smell.

These microbes grow in the A/C evaporator housing due to the moisture build-up caused by condensation. Toyota addresses this issue with their A/C Refresher Kit which when used kills the microbes growing within your A/C unit.

What is an AC Refresh?

The A/C Refresher service is a two-part process. … The second stage is where we apply a conditioning spray directly into the vents and intake ducts. Again, this is to capture and clean out any contaminants in your system, leaving you with a fresh, clean, scent-free vehicle. – Toyota

What You’ll Need

Trail Maintenance: 5th Gen 4Runner AC Refresh

Tools & Materials:

Find it Online:

Step 1. Locating the AC Evaporator Drain Hose

Trail Maintenance: 5th Gen 4Runner AC Refresh

Turn the steering wheel to the left and turn off the vehicle, this will maximize the workspace. Using the plastic pry bar remove the top two plastic clips on the aft splash guard.

Trail Maintenance: 5th Gen 4Runner AC Refresh

Locate the A/C evaporator drain hose. It’s the 90 degrees hose located right behind the rear plastic clip. If you are unsure water will drip from it if the A/C has been running.

Step 2. Extending the drain hose to the drain pan

Trail Maintenance: 5th Gen 4Runner AC Refresh

This step is optional but highly recommended. Since the drain hose points straight down towards the frame it’s a good idea to use a 3/8 barbed connector and hose to extend the drain hose down past the frame and towards the drain pan to keep the mess at a minimum.

Step 3. Dispensing A/C Power Foam Evaporator Cleaner

Trail Maintenance: 5th Gen 4Runner AC Refresh

Connect the AC Power Foam wedge adaptor to the drain tube extension. Push the wedge into the tube securely, it should be tight enough to where once you start dispensing the cleaning foam it stays put.

Trail Maintenance: 5th Gen 4Runner AC Refresh

Shake the can vigorously before dispensing the cleansing foam into the A/C evaporator housing.

You’ll want to dispense about half of a can worth of cleaning foam into the evaporator housing. Keep shaking the can as you dispense the foam.

The foam will expand once it leaves the canister and the pressure from the expansion will likely dislodge the wedge adaptor (wear eye protection to prevent this stuff from getting into your eyes) if this happens it is likely at the halfway point.

Trail Maintenance: 5th Gen 4Runner AC Refresh

After it expands the cleaning foam will liquify. Position the drain pan under the extension hose and let it drain for about 10 minutes. And then repeat the process again for the remainder of the cleaning foam.

Trail Maintenance: 5th Gen 4Runner AC Refresh

This is what came out of after cleaning my evaporator, yuck.

Step 4. Dispensing ConditionAire Ventilation System Refresher

Trail Maintenance: 5th Gen 4Runner AC Refresh

Close all the windows and remove anything living from the vehicle. Open the glove box and remove the cabin filter once the filter has been removed reinstall the cabin air filter cover (white one). Start up your vehicle and make sure the engine is running for this next section, doing this will prevent the battery from dying.

Trail Maintenance: 5th Gen 4Runner AC Refresh

Set the A/C Settings to the following:

  • FAN: HI
  • A/C: OFF

Close all windows and doors before the next step.

Start with the fan position set to “BODY” spray the ventilation system refresher into the cabin intake vent on the passenger side (under the passenger wiper blade) for about 30 seconds (the can says 45 seconds but that will leave you empty for the DEFROST step). Then set the fan position to “FLOOR” and repeat the process again. Finally set the fan position to “DEFROST” and spray the remaining content in the can until it is empty.

Trail Maintenance: 5th Gen 4Runner AC Refresh

Step 5. Venting the cabin

Trail Maintenance: 5th Gen 4Runner AC Refresh

Roll down the windows and allow the fan to run for another 6 minutes. Cycle thru the fan positions (BODY, FLOOR, and DEFROST) every two minutes

Step 6. Reinstall cabin filter

Trail Maintenance: 5th Gen 4Runner AC Refresh

Check the condition of your air filter if it needs replacing the part numbers for the air filters are 87139-YZZ10 or 87139-50100.

Reinstall the cabin air filter and turn the A/C to “ON”, drive around with the windows down until the smell from the spray is tolerable. The smell will eventually subside after a few drives.

Final Thoughts

I typically do this once a year during the summer months when the A/C is used a lot. This really helps with cutting down the microbes growing inside the A/C evaporator housing. However it doesn’t eliminate the funky smell completely, but it does cut down on the intensity and duration at startup. By doing this annually you are keeping the microbes from reaching critical mass smelling up your cabin which will ensure more pleasant drives to come!

Tip: I find that the best way to minimize this is to turn off the A/C compressor and run the fan on “HI” 5 minutes prior to arriving at your destination this will bringing the evaporator closer to the ambient temperature and reduce the moisture build-up once the car is off.

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7 months ago

Great write up…THX! Easy process that took less than an hour. Funk smell is GONE. One tip, make sure you let the ‘Step 1’ foamer fully drain before you turn on the fans…otherwise it pulls the foam up and spays out the vents. I put a beach towel on the seats just to make sure no splatter hit the leather.

7 months ago

I just did this and it works well with Toyota kit. I paid $28 for my but found that same Subaru kit is only $15. For those who does this each year it might be worth looking at. Subaru part # SOA 868V9315.

8 months ago

i see on the forum some people recommend to do this through the blue plug on the evap box on the driverside footwell. Is there a difference?

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