A/C questions and ramblings

[shadango]

Well, I just talked to the air conditioning guy.

He said he has everything back together and everything works great.

Said it's blowing nice Cold Air.

However, he was losing a little bit of coolant. So he used a sniffer looking for leaks.....everything is leak free....then he stuck the sniffer in the drain hose for the heater box.... He said he found "a small leak" from the evaporator.

He says he is going to try some sealer in it. He called it "Red Angel" I think...says its $50 a bottle....professional stuff....he says he usually doesn't like stuff like that sort of thing...better to repair the problem...BUT he used it before in his brother in laws car in a similar situation and saw good results. using it just on the evaporator from what I understood....Will ket it cure til this afternoon, refill the system and see if it leaks.

If the sealer doesn't work, we need to change the evaporator. And of course if it does work, then we're done.

But we are now in "plan for evaporator swap" mode.....anyone know what brand evaporators and heater cores will fit properly? Saw elsewhere here that some were having fitment issues with the chinese stuff.....which is everything now....

This guy will recore, would cost around $150 each unit and several days......

I have told my son to enlist the help of his fellow gearhead buddy and plan on figuring out removing the heater box.

I figure remove the front seat for one...the more room the better.....seat is easy to yank.

 

[78VOLAREWAG]

The ’80 uses the ’80-89 FMJ style Evaporator case design – which is way different from the ’76-79 design.

I have removed the evaporator cases on a ton of these cars – and in my opinion, it is not hard to do.
Taking the dash apart and keeping the screws separate (as well as not lost) is the big job.

I would agree with Aspen500 and get the A/C system leak checked first. These evaporator cores are not known to be big leakers as some other carlines are. No need to remove and replace something that is not needed to.

Also, I recommend converting to R-134a if you can, for R-12 is not easy to find. The A/C systems on our cars work fine with R-134a – providing you get all traces of old refrigerant oil out of the system, first.

My recommendation is to take car to shop that does A/C work. Have them perform a leak check on car. If a leak is found, then have then evacuate your existing refrigerant and document how much was removed. You go attack the source of the leak, then take car back to them to have the evacuation and recharge performed.

The evacuation and recharge is the part most people don’t have the equipment to do.
The rest of the A/C work I have confidence you can do.

If a problem if found, let us know and we can get you instructions to “get it done”.

Note: most A/C jobs both of you can do. Matter of fact, dash work is great for two people. One on each side of dash. One person doing the screwing then onto the next person. The non-busy person with Ziploc baggies and a marker marking down where screws came from, and so forth.
Great for father/son time.

I can remove an evap. case assembly in about 30 minutes, by myself, and about as much time to re-install (not counting evac/recharge). First timer - I would say about triple that time.
BudW

I wish it could be done that quickly on my 97 Ram.

 

[78VOLAREWAG]

Well, I just talked to the air conditioning guy.

He said he has everything back together and everything works great.

Said it's blowing nice Cold Air.

However, he was losing a little bit of coolant. So he used a sniffer looking for leaks.....everything is leak free....then he stuck the sniffer in the drain hose for the heater box.... He said he found "a small leak" from the evaporator.

He says he is going to try some sealer in it. He called it "Red Angel" I think...says its $50 a bottle....professional stuff....he says he usually doesn't like stuff like that sort of thing...better to repair the problem...BUT he used it before in his brother in laws car in a similar situation and saw good results. using it just on the evaporator from what I understood....Will ket it cure til this afternoon, refill the system and see if it leaks.

If the sealer doesn't work, we need to change the evaporator. And of course if it does work, then we're done.

But we are now in "plan for evaporator swap" mode.....anyone know what brand evaporators and heater cores will fit properly? Saw elsewhere here that some were having fitment issues with the chinese stuff.....which is everything now....

This guy will recore, would cost around $150 each unit and several days......

I have told my son to enlist the help of his fellow gearhead buddy and plan on figuring out removing the heater box.

I figure remove the front seat for one...the more room the better.....seat is easy to yank.

Red Angel is supposed to be the best stuff, AND, they offer a money back guarantee, if it doesn't.

 

[shadango]

What a day.

Got back from picking up the car from the shop....

Was working when we left the shop, and guy said he should drive the car for 15 miles or so and circulate the Red Angel.
So he and I went our separate ways.

After I am half way home he texts me and says he hears a leak and is headed back to shop…..I call him and tell him I will meet him there. I get there and I see him pulling off in the distance. WTF..lol...he got there before I did and the shop guy said just drive it and see what happens.

I caught up with the kid and by that time the sound stopped and the system was pumping out 50 degree air…..not bad. I watched the compressor cycle etc….

We went our separate ways again…got a text from him a half hour later saying Ok so far, 45 degrees….
He drive about 50 miles......came home, sat an hour , then went and put another 45 miles on it......got home at 3:30pm and all was well...still pumping cold air. 48 degrees.

So we were blissfully hopeful.

Just now, some 4 hours later, he goes back out to grab us dinner....well that was a short lived success.….nothing. No compressor action, nothing. Blowing hot air.

Dammit.

I guess the next step in the evaporator. Lovely.

I was so hoping that red angel would do the trick. He is so disappointed....like a cruel joke,....all day nice cold AC and then NOTHING....and we have heat wave coming, temps in the mid 90s....LOL

Sigh.

 

[BudW]

Most A/C leaks are either massive (major split in a hose, fractured line, bullet hole somewhere, etc. – or slow leaks (like bleeds out over one-plus months).

IT sounds more like an electrical problem to me, in this case.

If you have a multi-meter, I would perform an ohm test (for resistance) on the A/C clutch. If ok, then test to see if you have current going to other components from the A/C switch. With engine off, it is not common to have power going to the A/C clutch in many cases.
If you have access to a wiring diagram, then I would dig it out.
BudW

 

[shadango]

Most A/C leaks are either massive (major split in a hose, fractured line, bullet hole somewhere, etc. – or slow leaks (like bleeds out over one-plus months).

IT sounds more like an electrical problem to me, in this case.

If you have a multi-meter, I would perform an ohm test (for resistance) on the A/C clutch. If ok, then test to see if you have current going to other components from the A/C switch. With engine off, it is not common to have power going to the A/C clutch in many cases.
If you have access to a wiring diagram, then I would dig it out.
BudW

I just went out and put my AC pressure gauge on it...no pressure at all. Even tried manually depressing the valve , thinking my gauge could be bad....nothing....also tried depressing the schrader valve on the low side...nothing.

We snooped around, including a UV light we have.....we found some trace splatterings of an oily substance on the rad hose and shroud, on the side of it mostly....and the splatters glow under UV......it may be remnants of dye he used to look for leaks.....but I doubt any NEW leask will glow....because he did that dye test FIRST and then ended up flushing the whole system afterwards...so maybe splatters from originally working with it.....I am gonna ask him about that.

Also found a trace of oil hanging on one of the metal fittings on the small pipe/hose that goes between the condensor and the drier.....he flushed all the lines and cleaned them up, so that must be a new leak IMHO. But enough to drain the system??? There isn’t enough splatters or spray near that hose for it to be the culprit I don’t think.

I guess at this point the only way to go would be to do the evaporator/heater core as well as replace the pipes and lines with the custom made ones at NAPA.

 

[BudW]

The dye can show up years later (under a black light) – but if old, will usually be covered in dirt/grime.
The way to tell is to wipe the area with a rag and look at the rag (to see if dirt or oil or whatever).
The dye will not just “wipe off”. It will under high-pressure water or scrubbing.

Most shops add a couple ounces of dye for A/C work for checking for leaks.
Note: it is not uncommon to get some small amount of splatter when removing the A/C gauges.

In your case, it does sound like an A/C part has “suddenly” failed. Now we need to find out what.

I can’t speak for other shops, but what technique I use on servicing a freshly repaired A/C system is:
Let vacuum pump (portion of the A/C charging station) suck system down until you get a vacuum reading of 26 in Hg for a couple of minutes. Close all valves and turn off pump. Let car sit for 5 minutes and there should not be any loss of vacuum. If there is a vacuum loss (any loss) – then keep looking for the leak.

If no vacuum loss, then either A: have vacuum pump run again for about 10 minutes – if system was only open for a short time OR B: have vacuum pump run for an hour – if system has been open for a while.

Water boils under a vacuum – so what you are doing is removing any/all water moisture from A/C system via the vacuum pump.
Note: 26-inch Hg. Is the magic number, for water to boil.

Once that is done, you dial in how much R-134a to add to the system and the A/C Charging Station pumps it right into the system.

A lot of technicians I know do not perform the vacuum test. They just run vacuum pump for a few minutes (not long enough) then just add the R-134a into the system, bypassing the vacuum test.
Note: since the A/C system is under pressure all the time – I have found the vacuum test is a great aid to know if a leak is still present – before adding the R-134a.
Also – depending on where leak is at, sometimes you can hear the vacuum leak (or pressure leak) for some leaks are noisier under vacuum (or the other way around). Sometimes not noisy at all.
You have a large leak and you (the shop) will find the leak pretty quick.

What parts did your shop replace on car already?

I wouldn’t just toss parts at it without knowing for sure if leaking or not. Chrysler evaporator cores made in this time frame are not known to leak much (if any). The gaskets for A/C system are known to leak and hoses are – but not so much for evaporator cores.
BudW

 

[shadango]

Also – depending on where leak is at, sometimes you can hear the vacuum leak (or pressure leak) for some leaks are noisier under vacuum (or the other way around). Sometimes not noisy at all.
You have a large leak and you (the shop) will find the leak pretty quick.

What parts did your shop replace on car already?

I wouldn’t just toss parts at it without knowing for sure if leaking or not. Chrysler evaporator cores made in this time frame are not known to leak much (if any). The gaskets for A/C system are known to leak and hoses are – but not so much for evaporator cores.
BudW

AFter the shop went all over the system and replaced gaskets , cleaned hoses. flushed condensor etc, they ised a sniffer and found what they characterized as a small leak from the evaporator box drain tube.....that is why the shop decided to try the red angel sealer.

When we picked up the car the other day from the shop and was driving it, my son heard a steady loud hiss from under the dash.....no way to know if that was a leak or something else but my son said it was very steady. Then it stopped. Yet the AC kept working. We figured the sealer did its thing. It worked for several hours as he drove around. But after sitting a few hours in the heat, it lost everything.....so we are assuming the sealer started sealing the evaporator leak (the hiss) and then held a bit, but then after the whole system was hot and it was hot outside sitting still and building pressure it let go again.

We looked all over everything under the hood and like you said, we figure we have a LARGE leak and therefore would see a good deal of oil. The tiny amount of oil we found on the one hose crimp doesnt seem "big" and the shop even said that some seepage is normal from the old hoses....the shop is confident its the evaporator.

I sure HOPE its the evaporator.....such a big job. My son is starting the teardown today. Parts wont be here til tomorrow /thursday but we have to work on it when he isnt working.

 

[shadango]

So the box is out of the car. Found some red from what we think is the sealer the guy used…and a mouse house.

Parts will be here tomorrow ....reassembly starts on the 4th.

I helped here and there with guidance, holding a light, etc….I disconnected the AC lines and the heater hoses…he did everything else….Proud of the kiddo! Its 1 pm now…we started at about 8:30

The foam on a couple of the air blend doors is shot…not sure if we can do anything about that. Back when I did my Cuda's box I was able to buy a kit with all the precut foam etc. But they dont make those kits for the F bodies far as I know. Any ideas as to what can be use instead?? Or just leave it as is and put it all back together?

 

[shadango]

pic

 

[shadango]

pic

 

[shadango]

pic...note the red dotes/marks on 5-7 tubes

 

[shadango]

wide open spaces

 

[shadango]

This guy on youtube uses hardware store insulating foam rolls to redo the doors in his project......will this wrok well and not cause other issues? The foam he is using looks way thicker than the stuff thats in there now...

 

[Poly]

I can give you some suggestions for replacing the foam.

Did the same dissassembly, clean, reseal on the heater box, no air conditioning a couple years back. The foam seals, like yours, dissintegrated upon removal. We used neoprene from a huge roll that we have. It's 1/8 inch thick and worked very well.

 

[shadango]

Thanks...unfortunately I dont have access to that sort of thing.

I found some rubber foam self stick stuff from Home Depot that should work...I hope. its 3/16" think but pretty compressible.

 

[shadango]

Got the new heater core today...a Spectra 94614...supposed to be the "right" one...

Its wrong as far as I can tell...

smaller in dimension by 1/4" or so in both directions, that may not be a big deal....

It doesnt fit the rubber frame that the old one set in completely right, and maybe thats not a huge deal..

But the pipes come out crooked at the top, and the plate where the lid is supposed to bolt to is all crooked too...

NOT HAPPY.

 

[shadango]

Original pipes and mounting plate.....

 

[shadango]

Spectra crap

 

[BudW]

The foam falls apart after about 10 years of use, it seams, even on the new cars. Go to a hardware store and get what you can. Sometimes a hobby shop might even have something - what to use is not critical.
All it does is help with (door closing) noises and helps keeping the hot air away from cold air (for passenger comfort).

Every time I overhaul an evaporator case – what kinds of foam which is available at the hardware store changes, it appears.

Also get some thick foam for the seal on top of evaporator case to cowl area (top corner) – for if that seal is leaking, it will allow outside air (hot or cold) into cabin all the time.

This is a picture of the ’80-89 FMJ evaporator case (birds-eye view).
All air travels through the evaporator core. From there air flow goes through the heater core, or not, via the blend-air door. Sense there is a much greater temperature difference between heater core and evaporator core (outside temperature to 180/210’ vs. outside temp to 40’) the hot air is easier to control (if that makes sense).

The air flow doors (defroster, floor and bi-level door – the foam on them is not important at all.
The Blend-air door is the one that is more critical – but even then, it can go without, if needed.

Even then, you only need foam on the edges where they make contact. The foam in the middle of door, that doesn’t touch anything - makes no difference.

Compressible foam is great.


Also check your vacuum motors (vacuum pods) to make sure they hold vacuum, before reinstalling.
Adding a touch (a little goes a long way) of wheel bearing grease at all the pivot points do make things “move” a lot easier.
BudW


Edit: make sure the seals around each core (heater and evaporator) are in place as much as possible. Any air passing either core, is counter-productive – especially with the evaporator core.