OK, the War Dept wants me to fix the air in our '97 F-150 (auto, 4.6, 2wd) before we go on a weeks vacation.

I can find a evaporator (the part in side the cab) @ AZ/discount auto) but was wondering if anyone had some tips other than the Haynes manual.

Looks like a nightmare.

Maybe someone has an excerpt out of a regular manual I can read.

Thanks,
Jim

Sorry, got confused in the subject line. I need to replace the IN CAB unit thing....evaporator

 

It's a nightmare.

The whole dash has to come out, or at least be mostly disconnected and moved back.
You might as well change the heater core while you have it that far apart, and check the blend door too.

The heater core went in my 97 a few weeks ago, $750 total.
$80 for the core, which you can probably get for half that yourself....

I paid to have it done because I didn't really want to do it myself.
I told the wife it was because I didn't want to mess with the airbags.
I have done 4 on my Mustang, and one on my T-bird...I'd really rather have a root canal than ever do that job ever again.....

 

Wow, root canal. That stinks.

 

It' about that much fun......sorry.
That's why I paid someone else to do it.

I took comfort in knowing my mechanic won't be homeless for another month....

 

?
can I cut the box housing and get to it, then use A/C silver tape and shoot it black. Not like U will C it.

 

No. If you are going to do it, do it right. Cutting the box can lead to all sorts of grief. Removing the instrument and MVAC case is not "fun", but it's not bad if you have the manual and take your time. The job isn't "hard", it's just time consuming. Take lots of pics.
+1 on replace the heater core while you're in there.
I have the 97 Truck Service CD. PM me.

Are you absolutely sure the evaporator is bad? How do you know? I guess it could happen, but it's uncommon on those trucks unless they're starting to fail now due to age. I'd hate to see you tear it apart just to find the evap is good.

 

Yep, pulled the fan an stuck a air hose to blow it out and the evaporator is clogged big time like the freon leaked down from the top. Will hold a can or two for a couple days but will bleed down and I can't get air flow across the condenser. I don't think it would be anything else??

Will send PM, thank you very much.

Jim

 

Jim,
Is the debris oily looking/feeling? If so, yep, that's probably the leak.
Do some detective work first, though. Like I said before, I'd hate for you to pull the evap if it's not really leaking.

Debris plugged evaporators are common and you could very well have 2 totally separate issues. I've seen it before.
Every bit of the unfiltered incoming air goes through the evaporator regardless of Temp or Mode settings. So does all of the dust, dirt and debris pulled in from the outside air or from the passenger side footwell. It gets plastered against the wet evaporator and sticks to it. Being in FL, the evap will always be saturated with lots of condensed humidity to help trap the debris. The collection of "skundge" will usually start from the top and go down the face of the evap until the it's plugged. Once that process starts, it will continue even long after a separate issue takes out the refrigerant loop and the evaporator is no longer "wet" from humidity.

Your system will have UV dye in it from the factory. Since you can actually see the evap, go to Auto Zone or your other local "chain" parts store and get a UV leak detection kit (or a black light if you happen to have one left over from the 70's ) and the cool yellow glasses. Pull the blower motor and shine the UV light around. If the debris glows bright green, that's your leak.

If not, don't be so quick to replace the evaporator. Leaky evaps don't normally collect up enough crap to restrict airflow before the system quits, and evaporator debris doesn't usually just blow out easily. It clings like cement until you hit it with some type of detergent and water. Remember, you are blowing in the same airflow direction that got it there in the first place.Clean it through the blower opening with Simple Green from a spray bottle and your garden hose sprayer multiple times. Yep, it will make a really big, wet mess in your passenger floor. Keep the shop vac handy, and with a little scrubbing your passenger side carpet will look better than the rest of the carpet in the vehicle. It's only water, not grease, oil, or poison. It will dry quickly, especially there in FL in mid Summer. Be sure the evaporator drain is open when you are through.
After that, shine the UV light on all of the AC line crimps, connections and the front of the compressor. If there is foam wrapped around the accumulator "can" near the firewall, peel it back and look with the light. Any bright green is a leak.
.
Have your buddy add some oil and dye (from the kit) to the system and recharge it one last time. Shine the UV light on the evap again.

 

Haha, I have one and glasses

What blower opening are you referring to that I can get a garden hose through? I did have the blower out I have to turn into a pretzel to get to it. I do have a pressure washer I could blast it with .

I did add some stop leak and checked the under hood components w/a black light but didn't find anything and this was years ago (the air hasn't worked since 2004ish) and this is why the War dept is on my case to get it done before we go camping for the week in a few weeks. Hum, maybe it is just a clogged evaporator, not sure. In any case I could blast it clear, fill it, drive it, keep a can and repeat for the ride home but then again i have to deal with the War Dept.

 

Look what I found. WOW. Paying someone might be the way to go but in these hard times it might end up in the salvage year first.



Also someone suggested these:

 

This link will take you to a word document with detailed instructions for replacing the heater core. It should get you to the point needed for the evaporator too. Good luck!

http://my.voyager.net/~sscully/F-15097HtrCoreRepairF150_Exp_002.doc

 

Thanks John, I'll look into it.

 

Wow. It's easier to take a saws-all and cut a BIG hole in the dash or cut 1/2 the dash off. LOL

Good info John, not sure I can be a pretzel for 10hrs. Will look it over again, and again.

Thanks,
Jim

 

I can not take the credit for that document, I just book marked it if I ever need it.

 

I understand. I thank ALL of those who were involved.