Captain Obvious

Thanks bud. Appreciate the help. I did some digging around and I've turned up a couple of the cast iron versions. Now I have to wait a couple days while paypal uses my money for free. I didn't notice, but my acct had gone too low to pay for the wheel cylinders. As soon as they are done fondling my dollars, I'll buy some cylinders. I'm hoping the cast iron versions used the smaller hole seals. So in the event that I have to go through this again, I'll have the correct rebuild parts next time. @madkaw, Did your old ones turn up? Or did they leave the premises?

I put that wheel cylinder back together with my modified pistons and made it around the block, but I really have no idea about the longevity. I do know just from messing with them that the pistons really should be hardened, even if it's just a case hardening like the original. I know this because I had put a seal on the first piston just as a trial test fit, but when I took it back off, I could see the scrape marks from the tool I used to pry the seal off. With the machining modifications, I can now get the seal ON without tools, but I can't get it off by hand. Tools area required. The original hardened surface was hard enough to prevent those marks, but the softer underbelly beneath the hardening is not. So they may be fine until it comes time to replace the seals, and then I'm gonna scratch them up getting the seals off. So I'm going to order two new cylinders from the crapshoot that is rockauto, but the basic underlying mystery still remains... "The rebuild kits they sell do not fit the wheel cylinders they sell. WTF?" So a little more about the cast iron wheel cylinder you got. Guessing by the shape of the dust boot and the piston seal, it looks like the small seal design. I have a couple rebuild kits here that have boots and seals that look exactly like that. What brand cylinder were you ordering when you got that one? Of course, I have no idea if I would get the same version though. Even you didn't get two of the same when you ordered two of them!

Looks great. I bet mine looks like yours did. @zKars, So did your bearing fix result in the velvety smooth pedal feel you were striving for?

Yes, Granny... Sorry, I was talking to you. I saw the feet and got all confused. Thanks for the info. I suspect the cast iron units are older and have been knocked around. I think the aluminum casting versions are newer. In theory, form, fit, and function should all be the same. In theory. And Zed, I've actually got SIX cylinders and five of them leak. One good one on the car, and one leaker, and then four old ones hoarded away in a box on the shelf. I have a bunch of old dead seals there too, but the old dead ones are even worse than what's on my car. I looked everything over carefully trying to come up with a combination I could just run for a couple days while waiting for new replacements, but to no avail. However...... Because I hate to lose (well, that and some OCD), I figured I had extra pistons, so I chucked up a piston on the lathe and started cutting: First one turned out OK, so I did a second. Original pistons and seals on the left, modified on the right with the smaller hole seals: Put seals on the pistons, and they look great. Looks just like the one that Granny got: They slid nice and snug into the wheel cylinder, and while this is a temporary fix, I'm hoping it holds until new replacements get here. Someone may ask why it's just a temporary solution? Because during the machining, it was clear that the piston was case hardened, and I cut through the hardened skin down into the softer interior. If I were to heat treat the modified pistons, they could become a permanent solution, but I could probably purchase a lifetime supply of wheel cylinders for the cost of that heat treating.

Well I managed to force a small hole seal from one of the rebuild kits onto one of my pistons, and NFW is that gonna work. Here's the cylinder parts. Old original seal style on the bottom piston, and the newer small hole style on the top: And here's a closeup of the seals. You can clearly see that the seal on the top piston sticks out way to far. I did try and couldn't even get it into the cylinder bore. I couldn't even get that seal up over the piston rear without tools. I had to stretch it so far I was worried about tearing it. With lube, I managed to get it on with the help of two screwdrivers, but it's clearly wrong: This is killing me... I took the car down last Thursday with the expectation I would have it back together in a day. Slap some new seals in there, and put it back together. Done! Now it's one of the nicest weather weekends we've had all year, and I can't drive my Z because the stupid seals don't fit!!

And forgot... My spring is different too. Mine is straight and not tapered. And it doesn't "clip" onto the back of either piston. The raised bumps in the middle of the opposing pistons kinda locates it, but doesn't retain. It just floats there between the two.

Thanks for the input guys. Site, You ordered a pair and that's the pair that arrived? Mismatched from each other? So is that darker one that says "made in USA"... That one is cast iron? One of the rebuild kits I have (I think it's a new Wagner) has the same markings and shape on the dust boots. And it looks like the dark one uses the small hole seal. Can't really tell about the other cylinder. I think I'm going to force one of the small hole seals onto one of my pistons just to see what it looks like. I suspect it's going to bulge out so far there's no way it will fit into the bore. And madkaw, if you do manage to pull yours from the can before they get picked up... If they use the small hole seal design, I'd love to have them. I've got a lifetime supply of rebuild kits but nothing to use them on. Seems it's a potluck crapshoot of potentially mismatched castings from Rockauto.

77-78 Rear Brakes - A couple years ago, one of my rear wheel brake cylinders started leaking so I bought a pair of rebuild kits (WAGNER F96618) from Rock Auto. Problem is that when I took my cylinders apart, I discovered that the rebuild kit would not work for my cylinders because the piston seal was a different design and would not fit. Here's a pic showing one of my pistons, and the seals. Old (leaky) one on the left with the large hole, and new one from the rebuild kit that doesn't fit my piston because the hole is way to small: At that time I gave up and just bought a new pair of wheel cylinders (AUTOSPECIALTY / KELSEY-HAYES W51104) and put them in. Problem is that one of those cylinders is now leaking, and I'm back to the same problem again. The rebuild kits don't fit the wheel cylinder. They could use different piston designs inside, but here's what my cylinders look like from the outside: And there is this snippet from the 77 FSM. Seems it may have been a manufacturing source difference, but I don't know who won the contest: So, anyone have any insights? I know I could just purchase yet another pair of wheel cylinders... I mean, they're cheap enough! But the ones on there are so new, there's nothing wrong with them except the seals are leaking. A rebuild kit would be perfect. Problem is that all of the rebuild kits on Rockauto have pics of the seals with the small hole, and I've not found anything anywhere that looks like it has the large hole seal. Despite the fact that the new CYLINDERS you buy use the large hole style! At this point, I'm not even confident that I could purchase a pair of wheel cylinders and rebuild kits from the same manufacture at the same time and have them even be compatible! Anyone ever seen a rebuild kit that has the large hole style piston seal??? Any other ideas?

I understand completely, and I'm not telling you not to. Just bringing it up. Do whatever you need to do to finish the race! On a related note... I wonder how much heat the damper rubber can deal with. According to Loctite: The red thread lock "For removal, it may require localized heat (>550°F/260°C), hand tools, and disassembly while hot" And you've got quite a lot of thermal mass there. So hopefully once it's on, you won't have to ever worry about damaging the damper rubber because you just won't have to mess with it! And I hope I never have the problem you did!

There was a bunch of TVV discussion in this recent thread starting here: https://www.classiczcars.com/forums/topic/59296-bringing-a-1977-z-back-life/?page=12&tab=comments#comment-548626 And I believe @Av8ferg did find a suitable replacement for sale, but I don't know what the source was. Note that 78 is different than the earlier years.

Maybe it's because I've never had a damper come loose, but I don't think I would use red Loctite on those threads. I'm thinking thread lock blue would be enough? And when you said green on the bore... Are you talking about their sleeve retainer? If so, I wouldn't do that either. That's like belt, and suspenders. And nails, and screws, and bungee cords, and duct tape. If you use sleeve retainer on the bore and red on the threads, it's gonna take a lot of torch to get that stuff apart if you ever need to. Of course, all of my opinion might change if I ever had one come loose like you did, but that really sounds like a bit much. YMMV

And about getting the stock heat control valve out without pulling the dash or cutting the capillary tube? Sorry, but no way. Here's a relatively recent thread where we were talking about such things: https://www.classiczcars.com/forums/topic/58410-heater-valve-copper-thermostat-wire-do-i-have-to-remove-the-dash/

Been there. Done that. Not an absolute requirement, but you're right... It does help make things a little easier to work on. I figured I had the bead roller built anyway:

Could be. I was looking at mine installed on a seat, and I didn't go sticking anything through it to see if there were tiny holes. But do you think the holes are just molded in, or do you really really think it is a woven material made from thing strands interlaced? I still think it's one molded sheet, and as (anecdotal) evidence, I've seen 280 seats with that portion split open, and it did not fray into strands like a weave would. Or maybe it is really interlaced, but they heat bonded the strands together after weaving? I mean, this is a tiny, very unimportant piece of Z trivia though!

I put my second (rarely adjusted) valve in the return line back to the water pump inlet. It lives above my oil filter, and I adjusted it once or twice when I first put it in, and then took the handle off to save space. I put mine there because it was out of the way and the support clamps along the block keep that hose (and the valve) tucked up tight against the block. Now, the only caveat about putting the valve that far up the return leg is if you still have water flowing through the intake manifolds (as shown on that diagram you posted), then that flow will be cut off as well if you close the valve. Now, on my 280, I did not have that return leg around the back of the head, so the only thing that valve restricts is the heater core. If your 240 has flow around the back of the head, you should probably put it directly in one of the legs going only to the heater core. Doesn't matter which one though. I don't have any pics of my second valve, but when I get a chance, I'll snap a pic or two and post them. I used a brass bodied ball valve for PEX plumbing. I found the ends on it were a good fit into the 5/8 heater hose. Couple clamps and done. Like you said, whole thing is a couple inches long. Handle lives in the console now that I have it adjusted where I want it and I use the cable controlled valve for temp control of the heater.

Yes. Plugging the elbow nipple on the back corner of the head is the same thing as closing the water temperature control cocck. And if you are putting in a manually (hand) controlled ball valve, it doesn't matter which side of the core it goes on.

Beautiful. Take your time. If I were where you are, I wouldn't be in a hurry to get back!

Site, I've got two valves up in the engine compartment. One of them is cable controlled by the temp slider on the dash, and the other is a small PEX brass ball valve from the big home improvement store. I closed it about halfway and then took the handle off. I put that one in because the core got hotter than I really needed and I found that I only used the bottom 1/4 of the temp slider adjustment. With that additional (fixed) restriction in series with the temp control valve, I now use about 3/4 of the adjustment range. Which valve are you looking for pics? BTW - The temp slider valve was documented in a thread, but of course, the pics are gone because Photobucket extorted them out of existence: https://www.classiczcars.com/forums/topic/44009-heater-water-****-valve-relocation-project/

LOL. That intake looks great. Next time I'm in Toronto, I'm bringing all my aluminum parts to your place.

Yeah, I'm positive it's possible to do the Escort core without moving the water control valve out into the engine compartment, but it's tight. Just like the original system was tight. Little rats nest of short hoses and a whole bunch of leak sources. That's why I moved my water control out to the engine compartment in the first place. However I do believe the new plastic ball valve water control valves are way more reliable and leak resistant than the original brass things. I would be much more comfortable with a new style plastic valve in the interior than the old styles. You guys know... If you don't use the heat a lot and don't mess with the temperature other than twice a year, you could mount a small valve in the engine compartment without a remote cable connected to it. Open it up in the fall, and close it off in the spring? You'd have to open the hood and adjust the valve, but if you only ever use "full heat" or "full off" for your two seasons, then you could do that. Then you modulate the rest of the temperature with the air speed for the few days between "seasons".

Yes, the AAR is actuated by temperature alone. Some of that temperature is internally generated with an electrical heating coil, and some of that temperature is externally applied by the coolant running through the heating plate under the AAR, but yes... temperature alone. The colder it is out, the longer it takes to warm up. No computer control, but it works. And as Blue mentioned above, the "normal - once warmed up" idle air comes through a passage built into the throttle body. It's the large headed spring loaded screw on the throttle body. You can see it in the very very bottom left of this pic:

And here's a pic that may help both you and Jim. I never finalized the hose connections,, but I did test fit the Escort core with the original temp valve and vacuum shut-off. The one connection (right side in this pic) should be easy. The other end is more of a problem though. But this pic should help you on your way:

Understood, and admirable.

On the cars without factory air, that vacuum valve is not present. In fact none of the vacuum valves are present at all. The non-A/C cars (like my 77) have all manual cable controls and do not use vacuum at all. And although you didn't ask, that rarely ever stops me... Yes, the reason they put that vacuum shut off valve in place is to shut off all the water flow to the core whenever the A/C is on, but it's a little more complicated than that... The temperature control slider lever not only controls the temp for the heater, but it also controls the temp for the A/C by cycling the compressor. So if you want to be able to use that same control lever for both functions, you have to cut off the water when the A/C is on. Unfortunately the desired temperature ranges for the two functions are so wildly different that they couldn't use the same simple slider to do both controls without completely disabling the function that wasn't being used. Did I say that right? Does that even make sense?

Mike, Full disclosure, I did not actually install that version in a car, but I did place the blower assembly and connecting duct into place to verify that there was no interference. So, while I cannot guarantee with absolute certainty that I did not overlook something, I have a very high degree of confidence that it fits fine. Here's some pics of that version with the blower and duct in place. Top view: View from the firewall looking backwards: View from the interior looking towards the engine: