reassembly of the A/C and heater / was alarming ATF puddle, heater questions and a cold day in NOVA and aircon ignorance (1 Viewer)

[John Young]

Did you ever find out where this leak originated? I have one that looks just like it. My power steering high pressure hoses were replaced recently and I'm not losing fluid from the PS system. @BILT4ME - you mentioned a cracked dipstick O ring can cause this?

Hi Zack, no not yet. We got sidetracked by the heater core. Looking under the truck now the only puddle is from coolant that leaked when we disconnected the heater core:

Looks like a little drip from the transfer case area but nothing major:

The truck has not moved since December. I'm sure the alarming ATF leak will show up once I get it on the road again. I plan to check that dipstick o-ring idea.

 

[rolliges]

Cannot tell which gas by the fitting. If the fitting matches current US equipment, then the gas probably doesn't matter (but I am certainly no expert).
The expansion valve doesn't need to be done each time, but since you're in there you should. The receiver/dryer; yes, each time the system is opened.

 

[BILT4ME]

Did you ever find out where this leak originated? I have one that looks just like it. My power steering high pressure hoses were replaced recently and I'm not losing fluid from the PS system. @BILT4ME - you mentioned a cracked dipstick O ring can cause this?

Not me ( @Jgrauman ) but there is an o-ring where the upper section of dipstick tube meets the lower section about there. Maybe, but typical level is below that point.

 

[John Young]

Well, after a long Pandemic-induced hiatus, we are are back at the heater core. We took the plunge and depressurized the AC and once that was done we could get the AC box out (after what seemed like a dozen reluctant electrical connectors) and then the heater box came out pretty easily:

\

Victory at last!

Once we had the heater box out, the core simply slid out. My son noticed that the o-ring joint was rather loose, and for a moment there I was worried that that had been the only problem. If that was the only issue, we could have replaced the o-ring without pulling the AC or heater core. Thankfully, the o-ring was not the only problem. I put some water in the old heater core and it dribbled nicely out of the bottom proving that the core itself was bad.

While I have the heater and AC boxes out I am going to replace the degraded foam seals--all of which are just crumbling. I am getting a variety of foam tapes from amazon to do this with.

 

[John Young]

While we were doing this I've been trying to sus out what kind of refrigerant was actually in the truck. The only label I can find said R12. Now that I have the aircon box out I can see that it has a new expansion valve in it:

A little googling confirms that this is an R134A refrigerant expansion valve. The o-rings on this were of the new purple variety, so I think this was probably replaced in the recent past. What do you all think? Is there any point to replacing this.

 

[John Young]

I've been cleaning up the heater and aircon boxes. They were in good physical shape but the foam seals were absolute toast:

It just flakes off at a touch. I got some neoprene closed cell foam sticky tape from Amazon and I've replaced all the foam seals:

And I've cleaned up everything else:

One of the most tedious jobs was straightening the fins on the aircon evaporator. The aluminum fins are incredibly delicate and over the years it had gotten pretty beat up. But there was never any indication of a leak, so I'm not replacing it.

Now I've got to put it all back together. I've had a very difficult time finding good diagrams or descriptions after looking at the FSM's. If anyone can point me to a good exploded diagram I'd be most appreciative.

 

[John Young]

Some more progress today. Foolishly I had not taken enough photos while I was pulling things apart, so it took me quite some time to get the linkages vanes back in the right configuration, but I think I managed it.

I'd read here of others having difficulty with a leaking joint that Mr. T saw fit to put in the middle of the hot water intake pipe. I used a slightly oversized o-ring and also wrapped it with self vulcanizing tape (which I love to use).

Hopefully that will prove adequate.

Here are the two boxes fit together:

Unfortunately, when I was done I found I had not installed this:

If anyone has an idea as to where this ought to go, I'd be most grateful.

This is really learning by doing. One thing is for sure, I will have a lot more confidence if I have to do this with the other model 80's eventually coming from the Middle East. I also have a much clearer idea of what I want my mechanics in Dubai to do on the other trucks in this area.

I didn't use any lubrication on the pivot points for the vanes. It did not seem to need it and I was concerned about lubrication deteriorating the new foam tape I've put in. Maybe I should while it is out of the truck? I do have some white lithium grease. All the linkages seems to move nicely without it.

 

[John Young]

I did figure out where the mystery pipe went--on the left side sticking out towards the passengers. Must be part of the HVAC auto-climate control.

My older boy helped me place the heater box back in place.

Here is what the heater core pipes look like from the firewall side now:

They are much easier to access now. Extending them by a couple of inches more than stock was a very good idea.

Again with the help of my older boy we got the aircon evaporator box and the cross member in place. And most significantly, the steering wheel is now back where it is supposed to be:

I'm starting to think I might just possibly get this truck back together.

I don't see how one person alone can do a lot of these tasks. It really takes two people to position a lot of these items.

 

[John Young]

As per usual, I can't do things the simple way. I needed a vacuum pump to evacuate the system and check for leaks before putting the refrigerant in. I looked around on Craigslist and facebook marketplace and saw several suitable pumps for sale, and it came down to two: The first was a 2 stage pump from Robinair, which was modern, in good shape and a pretty nice pump, from somebody outside of Baltimore for 125 USD. The second was a strange old cast iron thing that looked like it was from the 1930s. Guess which one I had to have...

That's my older boy there. The pump appeared very little used, but it had funky oil in it. I took that part apart and cleaned it well and put in vacuum pump oil (which is special) and got a few fittings to adapt it to an A/C manifold gauge set. It makes the greatest sound when it is running. Kind of like what Fred McMurray's flying Model T sounded like in The Absent Minded Professor.

When I got to the point of connecting up the gauge manifold I found that the high pressure connector worked fine, but that the low pressure side did not have the quick disconnect fitting:

It had what looked to be an ordinary schrader valve. I was able to screw a hose onto it without too much difficulty.

It is pumping down now. I will leave it for a few more minutes and see how badly it leaks.

 

[John Young]

The patent for my new old pump was filed in 1939, so I'd expect that it was made sometime in the 40's

 

[John Young]

Apologies for how disjointed all my threads about this old Middle East truck have gotten. To sum it up, I figured out AC enough to pump down the system and refill it; I did a lot of wiring to clean things up, and I've gotten the truck back together again thankfully. I must have damaged a wiring harness or not plugged something in completely because now I have no 1st gear. So I'm going to have to tear the dash apart again and try to figure out what I did. Nevertheless we drove it a little during the last two days and it was very, very nice to have the truck back on the road, even limping as it is.

And just to make some of you jealous, the rear aircon is working fine now that I plugged in the switch in the dashboard.
And the factory Asin winch is working too:

Which thrilled my older boy who this truck belongs to--it was my college graduation gift to him.