2nd Gen Non-Engine/Transmission Changing the Evaporator

[GotDiesel]

I am fixing to change out the dreaded evaporator coil and I have armed myself with all the info that I can pull out of these threads. I do have a question though since I am tryin to make it better than it was, JSimpson made mention of epoxy coating the coil, can anyone explain what he was talking about? I tried to PM but he is not accepting them. What type of epoxy? Wouldn't that prevent the coil from working if you coated it, it does have to flow air right? Anybody out there knows any answers PLEASE post back as I am starting this project in about an hour. I will try to keep a good log of progress and post accordingly. Thanks in advance for any answers I get.

 

[parcher]

My experience has been that when you take the evaporator out there will be a small pile of rotting leaves in the box right where the coil has leaked. Did the leak cause the leaves... ... well, NO! Did the leaves cause the leak?... . BINGO! Find a way to keep foreign material out of the heater/ac box and you should be fine. I personally would not entertain the idea of coating an evaporator coil but that's just my opinion, I COULD BE WRONG!

 

[GMocanu]

Do not coat the evaporator with anything. If your evaporator has a leak then it is either from rubbing agianst something or a defect in the coil. BTW, leaves decomposing will not cause the coil to develop a leak.

 

[parcher]

Remind me to take a few digital pictures the next time I replace an evaporator.



GoMocanu, What is your statement based on? Mine is based on direct observation of about 100 or so evaporator replacement jobs in the course of 20 years as an auto tech.

 

[GMocanu]

Originally posted by parcher

Remind me to take a few digital pictures the next time I replace an evaporator.



GoMocanu, What is your statement based on? Mine is based on direct observation of about 100 or so evaporator replacement jobs in the course of 20 years as an auto tech.

My job is heating and air conditioning as well as electrical and plumbing. There is no way that anything other then a defect or something rubbing a whole in the evaporator in a '99 truck could cause this. Simple corrosion will not eat through a good coil in such a short period. The most likely reason for most of those 100 or so coil replacements is vibration causing a whole. You can put copper, untreated, underground and it lasts a long time so a few rotting leaves can not make a good coil go bad.



Now bad copper is a different story. Bad copper will develop leaks all on it's own with no outside influence. I have seen this first hand but then that would fall under the category of a defect. Also 100 or so evaporators or 20 years, when compared to how many cars you've worked on, could easily fall into the expected percentage for bad coils or vibration holes. Think about it, if leaves could cause this then most every evaporator would eventually have to be changed. After all, if it happened within 4 years on his truck wouldn't it also happen on many new cars before you even got done paying for them?



Parcher, please don't take me the wrong way. I'm just listing a few ideas for you to consider.

 

[parcher]

I found the difference in our opinions, automotive evaporator coils are for the most part ALUMINUM, not copper.

 

[GMocanu]

Originally posted by parcher

I found the difference in our opinions, automotive evaporator coils are for the most part ALUMINUM, not copper.

The fins attached to the coil are aluminum but are you saying that the coil itself is also aluminum?

 

[parcher]

The ENTIRE thing is aluminum, lock,stock and barrel !

 

[krs]

Now that we've got that settled can either of you offer any assistance to GotDiesel which might make his task easier for him?

 

[GMocanu]

Originally posted by KRS

Now that we've got that settled can either of you offer any assistance to GotDiesel which might make his task easier for him?

Well he should be done by now. Also both of us agreed that he should not apply anything to the coil.



As far as settling "the issue" goes, even with an all aluminum coil decomposing leaves will not cause a leak especially in a 4 year old coil. We have different opinions as to the cause of the leak but if he does what he can to protect against foreign objects entering the area that the coil is in and protects against something rubbing the coil then he should be in good shape.



I would also recommend trying to get a copper coil if he can.

 

[GotDiesel]

ITs FINISHED!!! YAY

I got it done finally, it took me a total of 10. 5 hrs. Sorry I didn't't post any pics. Lots of debris in the evap, leaves and such and I don't even park under any trees! I can only imagine what my wifes car looks like under there since she parks on the driveway under the trees. I did come across a few easy ways to probably knock off a couple of hours of unneeded labor.

First when the service manual says to remove the steering column, don't. All that is needed is to drop the column. Be sure to reconnect the gear indicator. On my 99 and I don't know if this holds true for any other years there is a piece of steel at the bottom of the dash that bridges the gap under the steering column, it removes with 5 screws then you can just drop the column down and not have to disconnect it under the hood. Believe me getting that shift rod off is a muther of a job. No room to get your hands in and lots of sharp objects to cut yourself on.

Second don't remove anything on the dash itself, there is no need because it comes out all in one piece, really cool IMO I remember working on some older GM cars and removing the dash was ten times worse.

The whole project cost me @ 300. 00 to complete. A lot cheaper than the $975. 00 I was quoted! Now what to do with all that money I saved???

 

[GMocanu]

A question or two.



Did you pull a vacuum before charging?



Could you locate the hole?



Oh yea, congrates on finishing. Now you can justify another $600 in bombing!!!!!

 

[GotDiesel]

I took it to a reputable shop and they did the vacuum and recharge. That was included in the parts pricing(65. 00)



Thanks for asking



Joe

 

[MDW]

Finally, Now I can borrow your truck again