Removing the evap coil

I'd recommend getting more opinions on how to clean it less invasively. What you're proposing will be very hard to see as practical. The refrigerant charge first needs to be safely drawn out and recovered. The lines need to be opened and sealed to prevent moisture ingress while you work. Then you'll be able to remove the evaporator, with not terribly many further steps once you are done removing the instrument panel. After you're done reassembling everything, the system needs to be resealed, drawn to a very deep vacuum, then properly recharged with refrigerant.

This is sort of a generic answer as you haven't indicated what your car is. I had an old Ford where the evap was accessible from under the hood, in fact, the whole A/C system, compressor, condenser, evap, and all piping, could be unhooked and lifted out (carefully, by a couple of people) without evacuating or unsealing the system at all. That was an uncommonly convenient design though.

If you are writing about a Toyota, and you're determined to put yourself through this, you can find the necessary steps in your service manual on techinfo.toyota.com. The equipment for evacuating and charging won't be cost-effective for you to buy for one job, so it would make sense to rely on a shop for those parts at least.

-Chap

 

Sure it'll work. You might have to duct-tape over some openings in the case. The A/C control might log codes.

If I were going to do that, I'd strongly consider taking out all the A/C parts, sealing baggies around the tube ends to help prevent moisture damage, and parting them out ... it's a lot of pricey stuff and somebody could use it (but you can't store it long, once you've had the refrigerant evacuated and the tubes open to air).

It sounds like a lot of trouble and a big resale hit on your car though ... are you sure you can't find somebody to do a better job of evap cleaning?

-Chap

 

Unless you are up to the task I won't pull the evaporator. Way too time consuming and expensive as the previous posters have suggested. I would consider the following as options: 1) Find a product like BG Frigi Clean and Frigi Fresh (Google it). I've self applied this product to all my vehicles except our Pri (it just hasn't exhibited any issues) with good success. It's a fairly easy DIY product, but not idiot-proof as in some evap cases you have to drill a hole in the plastic box to introduce the products. Just be advised. 2) Consider taking your car to a radiator-A/C specific repair shop, someone that specializes in auto A/C as they will likely have access to more effective specialized products/processes than a dealer.

Assuredly you have already replaced your cabin air filter as this can be a source of compromised air quality.

 

is the cabin filter moldy?

 

before you take the whole system apart (which is a giant job) pull the cabin filter and replace it with a charcoal filter, clean the cabin filter slot real good while you have it out, remove the small plastic door from you cowl tray and make sure the drain holes aren't clogged up, spray frigi-fresh into the cowl with the blower motor on full blast. make sure the evaporator case drain isn't clogged-- with the a/c on full blast on a hot day, verify there is condensation dripping under the car. if none of that helps then see if a shop you trust has any clue about sanitizing the evaporator box.

 

Toyota does that already (source: 2004 New Car Features Manual, page BE-97). Maybe the effectiveness drops over time?

If you think you might go to the work of removing the evaporator, maybe the thing to do is just put a new one in, which will have the coating at full strength. I don't think the part's actually that expensive, certainly not compared to the labor you need to get there.

I would be leery of adding any new thickness of any kind of coating to what's already there; it would change the heat transfer properties of the coil, and a whole A/C system is designed by doing that math very carefully.

-Chap