Captain Obvious

I haven't checked my car, but my assumption is that it's not a Canadian thing and my car has one as well. Smells like maple syrup maybe?

Its not cosmetic or fumes. (It's not sealed, and you can't see it normally). I'm guessing some sort of safety agency requirement. Something like "there must be a metal layer between anything containing fuel or vapor and the occupant interior." maybe? Only other guess would be noise reduction?

That rubber cap simply covers the adjustment screw for the throttle opener regulator. On the radiator end of that device there is an adjustment screw* to control the setpoint at what differential vacuum (manifold - atmospheric) the throttle opener pulls on the throttle linkage. * At least there is on later years... I don't know if such an adjustment was brought out to the user on such an early car.

If everything is working properly, the pistons should be hard to lift with a finger, but should fall easily. So the one that lifts easy has a problem. Something is wrong with the check valve jiggly bits on the end of the screwed-in stalk. Also, I'm not sure what you meant when you said that the rear carb has a return spring... If you are talking about the spring pushing the piston down, then they should BOTH have springs under the dome. Other thoughts? I don't like the looks of at least one of your needles. It looks like it's installed too deep into the piston, and it also looks chewed up and worn some at the hilt where it has probably been rubbing against the nozzle. The nozzle looks to be worn oval as well due to that contact. Dome/Piston/Needle/Nozzle alignment is very important, and the three screw round tops can be a problem if someone has cut off or dug out the dome alignment nubs (as has been done to yours). @Bruce Palmer Can describe the process necessary to align the domes (and hence the needles to the nozzles), but remember that each and every time you loosen or remove a dome, you must go through the same alignment procedure again. Here's your pic with the needle that looks worn: And here's your pic with what looks like a non-round nozzle hole that has been worn by contact with the needle:

Agreed. The most difficult part of the whole thing would be material selection and heat treat spec. The shims pictured were cut off as disks and then the groove in the bottom was cut in with an end mill, not ground. You can see the tool swirl marks and the line near the middle from the two pass process to remove the bulk material. My assumption is... Cut off raw material to rough length. Mill groove. Heat treat. Grind flat side to final thickness. Laser etch the thickness marking. Coat if necessary.

The Four Seasons 74604 is vacuum controlled. Normally closed. Here's a snippet from the Four Seasons catalog:

Fantastic job with the autopsy! So if that plunger and lower seal cannot be pushed out the bottom, then I'm not sure about the assembly process either! It's certainly possible that they soldered the assy together after putting the plunger and seal inside, but I consider that unlikely. Next time I have that box in hand, I'm gonna see if I can find my old valve. Maybe the plunger just needs a little persuasion to be pushed out the bottom?

Yeah, that's a really slick setup that Mike put together. But I think the brass bodied valve would be the only part I would look into doing different. The new all plastic ball valve types (like the Acura, Honda, Toyota stuff) just moves so easily, doesn't use a rubber seal to block flow, and will never corrode. If I were going to put a valve under the dash (where it wasn't easy to get to in the future), I would really try to use one of the all plastic varieties. That Four Seasons valve is nice because it has the cable anchoring point built in, but that is a surmountable issue. Heck... In fact, those plastic valves move so easily, if it were that close to the control lever, I might even be willing to try no second anchoring point at the valve at all. With that short of a cable, just the one anchor at the head unit might be enough.

Nice work Mike! Still a rats nest under there, but at least it's now a completely new rats nest. Should last quite some time! I had mentioned before that I was positive there was a way to do the Escort core and still keep the valve inside, and thanks for the confirmation. And I like your metal patches on the heater core cover. I just used hockey stick tape. If I go in there again, I may do something a little more elegant in the future.

There's simply no way that little girl looked like that just four years later. No way.

I'm looking forward to the autopsy. I love that sort of thing. As for what valve you find at the wreckers... Now that I've been through it once, I don't think you need to narrow your scope to that fine of a net. The 'best" option would be one that flows in the designed direction while having the control lever on the comfortable side and having the action in the proper direction. But since they are pretty much just ball valves inside, I'm really not sure how much the flow direction really matters. I'm thinking if you can find one with the control lever and actuation direction on the correct side, I wouldn't worry too much about the flow direction arrow. I don't remember the flow direction, but all the 96-2000 civics used a similar valve. And it wouldn't be a wrecking yard without having at least ten of those. Also, the mid-nineties Corolla (and Geo Prizm) used a right angle valve if you want to mess around with one of those as well. I didn't try one, but you might find it makes the plumbing easier.

When mine died, it did the same thing... Hot at all times. When you pushed your plunger way in and it finally sealed... It's not simply a problem with rubber that isn't flexible enough. I took mine apart too, and I went a little further than you did. Unbend the clips and the top plate comes off: Take off the cotter pin and brass support hat and the top seal will come off.: With that top seal off, it looks like this: And that's as far as I went. Now it's been several years since I was in this valve and I don't remember the details, but I'm positive... If it was easy to go further than this, I certainly would have. So my assumption is that it was NOT easy and I tossed it into a box in the garage somewhere and forgot about it. At that point, it was clear it was going to be easier to just move to something completely different than try to fix that one, so I bailed. I'm assuming there's a rubber seal on the bottom end of that rod that pushes against a machined seat down inside the valve in order to close the valve off. I also assume that rubber seal is completely turned to dust and doesn't seal anymore and that's why it flows at all times. Lastly, I assume from the fact that I didn't go any further than the above, that the assy has been pressed or brazed together making that seat impossible to get to without a torch or a saw. I'm sure someone has cut one completely open, or if not, I'd be happy to do it if I can find my original.

I reloaded the pics in the heater valve relocation thread. I'm sure there are easier ways to get a new valve in there, but here's what I did: https://www.classiczcars.com/forums/topic/44009-heater-water-****-valve-relocation-project/

Reloaded pics: The heater in my 77 always blew hot regardless of where I put the temperature slider and I tracked the problem down to a faulty water cokk valve under the dash. I had the capillary style valve (http://www.classiczcars.com/forums/thread46448.html) and spent a little time looking into a direct replacement, but after spending that kind of "quality time" working under the dash, I decided that I never wanted to go through that again. So I changed over to a ubiquitous newer style water control valve which I relocated up in the engine compartment instead of under the dash. I grabbed a bunch of different valves from the junkyard from various Honda and Toyota products, trying to find one that had the correct flow direction, had the lever on the proper side, and opened when the cable "pushed" instead of "pulled". I kinda lost track of which was which, but I believe the one I finally used was from a 2000 Acura TL. Here's the valve I used. Flow direction is left to right when lever is on the side pictured, and it's CW to open again with lever as pictured. That means I can mount it on the return line from the heater core and it's push to open. Note that I also had to make a new control arm for the valve to get the ratios correct between between the travel distance of the control slider and the travel distance of the new valve: I'm sure there are much simpler ways to mount a valve and connect to it but here's what I did. I made a mounting bracket for the valve which also included the provision for attaching the cable control: Here's the whole thing painted, mounted, and plumbed in the engine compartment. I attached it to the mounting bracket for the brake lines and fed the control cable through an existing hole in the firewall. I believe this hole is where the vacuum line goes for the HVAC system on cars with A/C. The hole location was a little higher than optimum, but since I don't have A/C, this hole was unused which saved me the trouble of drilling a new hole only to find out that the whole project was a mistake: It wasn't a mistake! It works great and will be a breeze to work on in the future if necessary.

And I was simply following his lead. I didn't even read your original post.

Sorry... I wasn't clear enough. There are other problems besides the soldering iron melting. The missing flapper door at the bottom won't do you any good without the front hinge mount. It's supposed to be part of the heater core cover as well, but that corner of the cover has been gnawed off. And there's material removed from the main air box in the same area. Like the front screw to hold the heater core cover in place stripped out and they chewed off the corner of the cover and air box in that area in a non-gentle way to get that cover off. Speculation. If that doesn't make sense, let me know and I can post some pics. In any event, I believe the main air box could be salvaged, but I think you're in the market for a replacement heater core cover. Or... You could just silicone that side flappy door shut with silicone. Here's the thread about installing the water control valve in the engine compartment. The pic links are all dead because of photobucket's extortion, but I'll upload new pics when I get a few more minutes. In the meantime... Here's the link: https://www.classiczcars.com/forums/topic/44009-heater-water-****-valve-relocation-project/

Thanks for the pics. Again, it seems the only problem cylinders (so far) are those "L" marked aftermarket versions. Both of those cylinders are brand new. I just think Wagner was private labeling the Tokico parts (at some time). Not really sure why since they had their own casting, but that's what it looks like to me. I have no idea which came first... Did Wagner private label the Tokico for some time and then decide there was more money in building their own mold and cutting Tokico out? Or did they build their own mold and offer a cast iron variety for a while before deciding for some reason that they didn't want to do that anymore and started private labeling the Tokicos instead? Mysteries that may never be solved, but the bottom line for me is that both of these cylinders can be rebuilt, while what I have on my car currently, cannot.

Here's that recent thread about the clutch pedal pivot pin: https://www.classiczcars.com/forums/topic/60310-squeaky-clutch-pedal-and-clevis-pin/

Well there's certainly some questions to be answered there. Both that heater core cover and the main airbox itself look to have been "modified" at some point. That cover looks like it was melted with a hot poker, and the whole front mounting screw area has been sawed off. You know... The section that originally contained the front hinge for the flapper door at the bottom. Without that hinge, someone might resort to completely removing that door and silicone-ing the whole door shut permanently and cutting a small hole above it instead. On the bright side of things... The cars that did not have A/C are a whole lot simpler than the ones that did. You don't have any vacuum controls or related solenoid valves, etc.

Haha! Well if someone wants to set something up, I'd be happy to participate! Not sure I'm qualified, but I can twiddle some knobs and stuff!

And my old "L" logo cylinders... I bought that pair from Rockauto some time ago, and they were AUTOSPECIALTY / KELSEY-HAYES W51104 and while there are no markings on the cylinders themselves, the box said "Made in China". Oh, and forgot... The other side of the Tokico has "Japan" cast into it.

Where were they made? Interesting story... The labeling on the one box which contained the Tokico cylinder looks like this. Has made in Japan on it in a couple locations. On both the UPC label with the Wagner P/N: And another sticker elsewhere on the box: The OTHER cylinder... Made by Wagner in a Wagner box. Clearly has "Wagner U.S.A." cast into the cylinder body: And interestingly, there is no "made in Japan" sticker on the back of the box, and the UPC label looks like this: I you look at that UPC sticker at the correct angle under the correct light, you can see that it says "Japan" under the black marker. I don't know who obscured the label, or how many years ago, but it's certainly interesting.

What's with the hole in the heater core cover? Looks like someone cut the cover at one time? Presumably to use a different heater core with a tube in a different location maybe?

I agree 1000%. I never ever realized the huge list of small refinement changes that were made along the way until I started hanging out here and learning. I assume all the refinements did come with a weight penalty, but I'd be curious as to how much that really was. Couple hundred pounds maybe? So about the heater valve... That valve is stock and that copper tube is a temperature sensor. It works in conjunction with the valve to limit the upper end of temperature. I don't know what temp they had it set for, but they were trying to regulate the temperature of the air and cap it at an upper limit. As the air heats up, it heats up that coil inside the air box. And the gas trapped (or was trapped at some time) inside that tube expands. When that gas expands, it closes down the valve a little, thereby regulating the temperature. My original valve was dead (as yours is probably as well), and that's why I went with the generic ball valve. As part of that whole process, I found the ball valve (which opens to a full bore flow) passes way more water than desired and the heater core gets way hotter than necessary. I found that I always used the bottom 10% of the temperature control, even on cold days. That's why I put a second valve that I set and forget to limit the upper end.

Update... I purchased a couple wheel cylinders off ebay, and at this time I've got a Tokico (which uses an aluminum body) and a Wagner (which uses a cast iron body). Interesting to note, however that both of these cylinders were in Wagner boxes, even though one of them is a private labeled Tokico. Here's a pic of the two with one of the pistons pulled out of each: And looking closely at the seals they used, both of these cylinders could easily be rebuilt by the plethora of rebuild kits available everywhere. I didn't pull the seals off the pistons because of the damage risk, but here's a close-up where you can see how deep the seal goes onto the piston. They clearly use the smaller holed seals. This is the Wagner branded piston: And this is the piston from the Tokico branded piston. Note the dried up crusty grease from sitting on someone shelf for decades: So... As far as the whole rebuilding process, it's starting to look like many of the wheel cylinders out there can easily be rebuilt with the ubiquitous rebuild kits, and so far the only ones that CAN'T are the ones that are (and were) on my car. I don't know who the manufacturer is of these cylinders with the "L" logo, but they are the only ones I've found so far that will not work with the rebuild kits. If you want to be able to rebuild your cylinders in the future, avoid these made in China versions: