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AC = Major Mistake

Big T

Big T

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OK, now I'm thinking this was a major mistake to take on this project.

So I'm going through the system. Found and replaced the orifice. Went to remove the dryer and that's where I ran into problems. What appears to be a nut on the pipe coming from the firewall is just the pipe. So now I've kinked that pipe trying to remove the dryer. Worse yet, the new AC Delco made in China dryer ends up in the 9 o'clock position when snugged tight. In the normal 6 o'clock position it swings freely. It's looking like I f'd this up but good. Do I put the old dryer on? Do I double up on seals? If I twist the pipe at the firewall anymore, it's going to break.:rolleyes5:
 
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buddy said:
If you opened the system you should always purge/evacuate and replace an old dryer anyway.
Click to expand...

The new dryer only fits snug in a position where the radiator overflow tank sits. So it's not going to work?????????????????????????????????????????
 
Big T said:
What appears to be a nut on the pipe coming from the firewall is just the pipe. If I twist the pipe at the firewall anymore, it's going to break.:rolleyes5:
Click to expand...

No, you just have a major problem. The nut is in fact a nut and is rusted to the evaporator. A minor leak there will mix the gas and condensed water to form acid. major rust results in what you have. I am surprised you even got the dryer off.

:grouphug: Oh what the hell, the old evaporator is likely plugged up with years of dirt and could use replacement anyway. Not a fun job, but with the rusted stuck nut you are there.
 
Yeah, they make a repair kit where you can cut the tube and compression fitting on a new end but that is for the orifice side of the older ones and they only work with limited sucess. Your screwed. Replace the dryer. Suck to do on NBS truck bigtime. Piece of cake on OBS. If you put enough force on that to twist it, it's junk.
 
probably a dangerous idea to do in vehicle, but i had to melt the orifice tube out of my blazer's original Evaporator since it was so badly stuck in there. I did this in the garage, with a bottle of water handy in case I set something on fire. It worked save for a little flamage when the orifice tube came out and burst into flames from touching the torch flame. A side effect of heating the aluminum tube with a handheld propane torch, was that the nut at the end, which is figured didn't turn, spun slightly and then spun freely after a few more quick sessions with Mr. torch.

I do not recommend this in the vehicle. How badly have you kinked the evaporator tube? If it's bad I'd replace it. The last evaporator i bought from the junkyard was the replacement for my blazer. Anyone who's seen the evaporator's for the 80s GM trucks knows they are huge. Out the door it cost me $20. A new evap was anywhere from $90(made in china junk) to $130(made in USA).
 
WarWagon said:
No, you just have a major problem. The nut is in fact a nut and is rusted to the evaporator. A minor leak there will mix the gas and condensed water to form acid. major rust results in what you have. I am surprised you even got the dryer off.

:grouphug: Oh what the hell, the old evaporator is likely plugged up with years of dirt and could use replacement anyway. Not a fun job, but with the rusted stuck nut you are there.
Click to expand...

Where is there?

Please explain how I replace the evaporator?

BTW I could not get the fittings off the condensor either. I guess this is my reward for buying a truck from Illinois? I assume that I should get a new condensor while I'm at it?

Here's some pics for amusement:



Rockauto shows two AC Delco evaporators:

ACDELCO Part # 156948 {#52481081}
EVAPORATOR,AUX A/C OEM PRODUCTION INSTALLED, Used Together With 52406098
Price: $184.99

ACDELCO Part # 156794 {#52464036}
EVAPORATOR,A/C
Price: $192.79

Which one do I get?

WHILE I'M ORDERING, ANYTHING ELSE I NEED?

Looks like the margaritas will be extra strong tonight.
 
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yup evap's junk.

You could try warming the fittings with a propane torch on the condenser if your feeling lucky.

My fittings weren't that stuck on a system that's twice as old. There should be 2 fittings. one on the condenser, another on the line in the case of the condenser. IT will be teh same anywhere else a line/hose is threaded into something. Put a wrench on both to help with removal. A wrench on one will bend the tube on the side with no wrench as it will just want to twist around. It's the only sure fire way of not twisting a line, however with enough force and a poorly fitting wrench(or not using a line wrench) you can cause the fitting to round off. Then your really screwed.

That being said, I didn't use line wrenches on any of my fittings. I even used adjustable wrenches on the accumulator fittings, however the adjustable i have was made in the 30s or 40s and is an inch thick at the jaws and weighs probably 10 lbs so i know it's a damn good wrench. Don't use cheap wrenches either as the jaws can spread on the inferior chinese crap and it'll slip.
 
Think of the evaporator as a sort of hear core but it makes cold instead. And we know how much fun heater cores are to change...Basically you have to pu8ll the dash and pull the HVAC box out of the truck. I have never done one on NBS so someone else can chime in on that. I know the dash tips forward.
 
Acesneights1 said:
Think of the evaporator as a sort of hear core but it makes cold instead. And we know how much fun heater cores are to change...Basically you have to pu8ll the dash and pull the HVAC box out of the truck. I have never done one on NBS so someone else can chime in on that. I know the dash tips forward.
Click to expand...

I've done heater cores on a '73 Bronco and that was no fun.

Yes, I need the dash removal for dummies lecture here. I'm waiting and I'm going to be mixing some strong drinks.:redneck:
 
Did this on a 96 a few years back. I was helping an experienced mechanic and it took over 8 hours. Yes, go ahead and replace both the heater core and the evap. core while you have it exposed.

Have fun!!

Todd
 
iamdave0887 said:
yup evap's junk.

You could try warming the fittings with a propane torch on the condenser if your feeling lucky.

My fittings weren't that stuck on a system that's twice as old. There should be 2 fittings. one on the condenser, another on the line in the case of the condenser. IT will be teh same anywhere else a line/hose is threaded into something. Put a wrench on both to help with removal. A wrench on one will bend the tube on the side with no wrench as it will just want to twist around. It's the only sure fire way of not twisting a line, however with enough force and a poorly fitting wrench(or not using a line wrench) you can cause the fitting to round off. Then your really screwed.

That being said, I didn't use line wrenches on any of my fittings. I even used adjustable wrenches on the accumulator fittings, however the adjustable i have was made in the 30s or 40s and is an inch thick at the jaws and weighs probably 10 lbs so i know it's a damn good wrench. Don't use cheap wrenches either as the jaws can spread on the inferior chinese crap and it'll slip.
Click to expand...

I did use two Craftsman wrenches and still got the result you see in the pictures. The evaporator pipe was the path of least resistance.
 
It shouldn't have twisted like that if you were using two properly fitting wrenches. maybe it was weak before you started?

I agree on changing the heater core as well while your in there. If you don't you know it's going to leak the second you get everything back together. Damn that Murphy and his law. :prrr:
 
I've got the same issue going on with the condensor: Nuts are rusted in place and I cannot break them apart with the big wrenchs. Do I apply heat there? Or do I just get a new condensor? Will I need new lines going into the condensor?

I really need a complete parts list so that I can get to work on this next weekend. I travel/work in Chicago during the week and do not have the luxury of running down parts during the week. I need them shipped to my door. Looking for help here guys as my weekend time is very limited and I need this rig for towing my boat. It's tournament season.
 
iamdave0887 said:
It shouldn't have twisted like that if you were using two properly fitting wrenches. maybe it was weak before you started?

I agree on changing the heater core as well while your in there. If you don't you know it's going to leak the second you get everything back together. Damn that Murphy and his law. :prrr:
Click to expand...

No they were properly fitted wrenches. That nut is basically welded in place. The evaporator pipe was just the weakest point.
 
I replaced condenser on my 98 Suburban because I finally got the lines off, but twisted the pipes to it. But more importantly, the nuts on the hose lines had been filled with the threads of the condenser lines after I broke them loose(lots of PB Blaster). I tried to clean the threads, but to no avail. New condenser @ rockAuto for $84. got new hose lines @ the local part store at around $25 each. PITA to get off.
And the nut at the firewall is a nut and should turn. Still was a PITA to get the dryer to thread to it. I do believe I'll NEVER touch AC systems again if I can help it. Good luck.
 
use a very small dab of anti sieze on the pipe shaft where the nut rides and on the nut threads. DO NOT get ANY near the Oring or in the A/C system.
 
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