Heater Plenum Issue

[Mike Wenrich]

Got everything together and now back under the hood with the realization that I did not mark the heater hoses location. Would appreciate someone looking under the hood on one of these third gens to tell me where the hose to the cylinder head is routed on the plenum. Top or bottom outlet on the heater core? I think it's the top but cannot recollect for certain. Should be able to test this rebuild soon after I get the info. Books/manuals that I have searched don't show this.

 

[Ozymandias]

Cylinder head goes to upper connection.

 

[Mike Wenrich]

Ordered two different pair of hose pliers but waiting for those and installed my new heater hoses today. Found out the new hose end clamp to the core is vulcanized to the hose. That made it difficult, make that impossible, to get it installed on the core. If I had the tool I might have been able to do it but I really doubt it given the terrible access to the core. I got three out of the four on and fought like hell with the last one that went to the bottom of the core. I even used a craft razor to remove the clamp so I could put them on one at a time. Got the hose on but no go on the clamp after trying no less than 15 different pliers I have. Then after a break and clearing my head I walked by my anvil and sets of tongs. One of the tongs has slots to hold 3/8 bar stock and grooves on the jaw sides to work metal at a right angle. Thought what the hell. Give 'em a try. 3 minutes later the clamp was in place. An hour of fighting reduced to 3 minutes.

Put anti freeze in and had an issue there. Separate post for that but while I was running the engine I tested the dual control functions and they work great. I'm getting more air out of the vents than I have in years. The blend doors were probably bad for a long time and I did not know as they failed gradually over time. I only found one broken but the piece I found that broke off does not make up all the damage on the door. So it was probably not opening/closing for a long time.

Only thing I noticed from my work is the brake lights are remaining on so I need to get back under the dash and see what adjustment needs to be made to bring the pedal closer to the switch. I know I reinserted it by twisting it into place but somehow made a mistake. Disconnected the batteries for the night. Oh...and I found a couple of those seemingly hundred little black dash screws left over. May have a rattle until I figure where I missed the spot for those. Once again I appreciate the help on this build. I have to do another one so hopefully I breeze through that one.

 

[BigPapa]

I’ve heard of people resetting the brake light switch, but I’ve never been able to. I’d suggest getting a new one.

 

[Mike Wenrich]

Replaced the switch today after seeing that a tang was broken off and THEN saw the print on the switch "Do Not Re-install". The switch had become dislodged when I was doing the work under there. Don't have any idea why that is but the local parts supply had one on the shelf and it's in and working. So you were correct BigPapa. The directions tell you to install it and then flip a tang to "adjust" it. Did that because after the install the lights were not coming on. It's not really an adjustment because you don't have a choice of position. It just clicks and then the lights worked. Directions say to follow the install procedure and do not remove. It's a one time, one chance to get it right.

 

[User113]

I'm not sure how they work, but I ignored that "do not reinstall" warning and didn't have any issues. Perhaps just lucky? Maybe I'll take one apart if I ever have to take it out again.

 

[Ozymandias]

As long as it stays in the same vehicle and nothing was bent or changed all is good.
The idea is to not swap it between vehicles or with changed main components from the assembly.

 

[Mike Wenrich]

I'm planning on taking mine apart to figure out why I can't move the adjust tang back and why the old one, when removed, had a shorter "throw" than the new one. That was the reason it did not work. It was at least 1/2" shorter than the replacement. Hope it doesn't self destruct and send debris all over the garage.

 

[BigPapa]

You probably pushed it in by accident. That’s how it’s made. It’s all the way out when you put it on, then it pushes in and self-adjusts. It will push in further, it just won’t pull back out.

 

[Mike Wenrich]

That makes sense now. I took mine apart and saw a metal sleeve that I was able to manually move with a screwdriver to get more extension but I could not figure out how it was set up when new. Nor could I get the outside adjust lever to lock in place like the new one. Since it goes to a fixed position I suppose that is why it says do not reinstall. Meaning in another vehicle. Or if you have altered the adjustment like I did. I'm pretty sure I pushed it in and pulled on it trying to see if was just stuck.

A neighbor with a 2015 truck told me last evening he reinstalled his with no problem. But his may be different because he mentioned his lights stayed on after he replaced the heater core and he was able to adjust it. Made a clicking noise when he moved it closer to the pedal arm so maybe it's on an assembly that can be manually adjusted.