Putting in a replacement L-28

[SteveJ]

17 minutes ago, Captain Obvious said:

At quick glance, I think the way you had it first may be correct?

Based on the design, the inlet leg on the temp control valve should be the straight leg, and the outlet side should be the one that comes off sticking out the side.

And on the engine... The connection pushing water into the core is the one at the back of the head, and the connection returning to the water pump is the longer hose running near the oil filter. So with that in mind, you ought to be able to determine which hose goes where?

a) Head outlet to vacuum cokk inlet.
b) Vacuum cokk outlet to temp valve inlet.
c) Temp valve outlet to heater core inlet.
d) Heater core outlet back to water pump.

 

Are you thinking it's documented wrong in the parts manual and FSMs?

[Av8ferg]

Oh crap…. I hope you are wrong Bruce. I just got the whole thing reinstalled. I found a link to a guy who documented the changing of the heater core. He puts it back together like the FSM states. Doesn’t mean he’s right but more community confirmation?

http://www.maplesoft.net/datsun/repairandupgrade/heatercore/index.htm


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[Barefootdan]

@Av8ferg You're going to be a master HVAC installer for this chassis by the time you're done! Don't panic yet 🙂 

[Captain Obvious]

5 minutes ago, Av8ferg said:

Oh crap…. I hope you are wrong Bruce. I just got the whole thing reinstalled.

Actually, this might answer the question... I found this pic that indicates the flow direction through the temp control valve is actually opposite of what I said above. Shows what I know, right?  :

So carry on and don't panic? 

[Av8ferg]

Whew….I really didn’t want to pull that out….again.   Thanks 

[SteveJ]

7 minutes ago, Av8ferg said:

Whew….I really didn’t want to pull that out….again.   Thanks 

Do we ever? 😉 

[Av8ferg]

Like so many things on this car, you become almost an install and removal expert when you do something 3 times.   I’ve stopping tighten things down until the last minute because I’m all 100% sure I’ll be removing the screw or bolt in short order.   It almost like you have to do it 2 or 3 times to figure it out,  .   

[Captain Obvious]

1 hour ago, Av8ferg said:

almost like you have to do it 2 or 3 times to figure it out,  .   

That's what I mostly do.

But why stop at three?    

[Av8ferg]

Getting close to getting everything reattached so I can re-install the new dash.   When putting the heat box back in I has to push the heater controller back and while doing that the cable the connects to the heater control valve pooped off the end on the control panel.   Now if can’t figure out where it attaches.  My assumption is it would connect tot the temp lever but I don’t see a connect point.  See pic below.  In the pic I’m holding the cable.  The other end is connected to the heater control valve.   This has all be en apart about 6+ weeks so I can’t recall every connection.  I also see a cable connection to the right side of the blower motor.   This must be the fresh vs recirculate switch.  I don’t even have this cable so I’ll need to find or make one.  
 

Edited February 28, 2022 by Av8ferg

[Captain Obvious]

1 hour ago, Av8ferg said:

 the cable pooped off the end.   Now if can’t figure out where it attaches.

Man I hate when that happens.

So here's a pic of the temp control lever. It's on the underside (the radio side) of the assembly. That might be why you can't find it. I don't have a good pic of it in-situ, but here's the lever solo. The cable connection point is one of the small holes at the top in the pic:

And here's a pic of the whole airbox assy. The temp cable is the one that comes out at the 6:00 position. The jacket is supposed to be held in place by one of those ubiquitous cable clamp thingies:

 

 

[Captain Obvious]

And about the fresh/recirc control cable... Don't worry about it because you don't have one.

The vacuum control actuator "takes care of that for you". They always switch over to recirc when you hit A/C. One of the flaws (IMHO) in the system, but that's how it works. There is no provision for you to switch over to recirc unless you turn the A/C on.

[Av8ferg]

Thanks Bruce. You heater controls and box look very clean compared to mine. I now see where the cable goes , thanks for the pics. I just need to find the metal clips that hold the sheathing of the wire to the frame. There are 4 total in the system and I’ve misplaced 2. I guess that means it’s time to give the shop a full cleaning. I have lots of craps all over.
I’m so close yet still far away. This whole HVAC…(heater core, valve rebuild) was an unexpected set back in this project but with a new dash it was better to find out now then after install.
Before I install the dash I’m going to start the car and check for leaks just to make sure I don’t repeat another task.