Evaporator flush procedure

Hi all,

I have a 2006 Tacoma V6 4.0L and will be replacing the expansion valve which I'm hoping I can do through the engine side firewall.

Since I'm doing this I wanted to flush the evaporator. From what I can tell once the expansion valve is out there will be two female hose connections on the evaporator sitting back a couple inches behind the firewall with just a small opening to get at these.

I've got a flush gun and was going to try to flush with brake cleaner and then blow out with fairly dry compressed air but didn't want the old oil and junk in the evaporator blowing out all over the place.

I'm wondering if it would be possible to get a couple clear water type hoses pushed into the female connections on the evap and have them seal off good enough.

Anyone got any experience on doing this job and what setup you used.

Thanks

I'm no

 

Flush with 90% rubbing alcohol instead of brake clean. Cheaper and way better.

 

The dash has to come out.

 

Did you have a catastrophic compressor failure? If no major failure of machanicals, the flush is really not needed...as well as the x valve.

 

I’ve looked at several exploded views, you might just be able to go through the firewall. If you can that would be awesome, pulling the dash sucks.

 

I wanted to "like" this post, but who would "like" pulling the dash...

 

I’ve pulled a dash it’s a lot of work.

 

@Orbang

OP, yes indeed you can flush the evaporator from the engine compartment side of the fire wall without having to remove the dash.

I had a spare of the 2-tube connector piece used to connect the expansion valve with the high/low hoses and adapted a couple of clear hoses to the nipples. Careful you don't scratch the nipples as you will need to reuse.

However, before you proceed make sure you are serious about the need to flush the evaporator. I would not consider it unless the AC compressor grenaded and/or you found a bunch of debris in the tube-microscreen at the expansion valve, even then I would reevaluate the situation. After all that screen is there to catch debris. And if you decide to proceed make sure it is flushed from both directions.

The suggestion about using alcohol above is good and can be had in a gallon size from a home improvement store. The clear hoses can help see if all the AC oil is removed. Warning: this can be a lengthy job and the real pros often recommend using a pulsating-type flush gun.

In the end you want the inside of the evaporator totally dry. I rented a nitrogen tank and regulator from a gas supply place and let the gas run through the evaporator over night.

 

Nope, It doesn't:

https://www.tacomaworld.com/threads/a-c-filter-screen.482864/#post-24272716

 

Thanks all for the input. In the end I decided not to flush the evap. I couldn't get two hoses on the male connectors good enough to be confident that a high pressure flush would work and I was concerned I would end up with the evap having flush liquid heing left in it.

I did find a little bit of metal shavings in the high pressure line screen at the evap. But my thinking is that it shouldn't have got past that filter into the evap. I did flush out all three lines and I am replacing the expansion valve, condenser and compressor so that will be all clean.

Didn't get much oil out of the lines. Probably 1/4 oz. Not sure what is left in the evap. I put the 4 oz in the compressor and will probably put 1/2 oz in the condenser. The whole system for a 2006 v6 4. 0 l should take 5 oz so I think I will be good.

Still waiting on a rad so will get back to this job in a bit. Will let everyone know how it goes.

 

Snip.

Suppose I should read a thread completely before replying. Lol.

On that note, what jimmyh said.