2 Attachment(s)
Confirmed: you cannot change the hot water control valve from just under the hood.
Someone said they've done it, but I don't see how. You might be able to somehow remove the screws by rotating the tips of the screws out, but there's no way in the world you could get them back into position without taking apart the whole footwell. I've changed all the vacuum lines before, but they've been on cars where everything worked. Nothing worked on Al's '57, except the antenna, No wipers, no spritzers, no heater controller and no vacuum advance.
When I pulled the engine to get to the trans I bought a kit, installed half of it and it cured nothing. I get 20 inches at the manifold tap and 12 inside the car. I bypassed the pump and got 18 inches at the tube at the left-front of the engine. That seemed strange I used a wire through two short bends and a long one. Some debris came out but not much. From that tube it jumps across to a T on the chassis with a hose branching off to the washer bottle and another to bring vacuum to the firewall where it branches off to the wiper motor and then feeds the inside of the cabin. I'm beginning to wonder if the lowest tube is rotted out from the inside as I found it with washer fluid in it.
My real discovery today is that you can replace the vacuum valve from just inside the passenger compartment, but it tricky, and likely where this car gets a reputation for being difficult to work on. It would be a ton easier to have both sides open, but much easier without a hood, hinges and fenders, which means you have to take the front bumper off to get to one tiny trim screw that let's you take the grill out.
Attachment 29583
Working from the inside the whole left footwell has to come apart. The packaging is so tight you have to take two things apart to get to a hidden screw. The diverter box has to come off and detached from the cable. There is a screw below that's easy to miss. That gets you to the duct where the thermostatic device is mounted with two screws from inside. That sets the device almost free. It's still restrained by the control cable that secured by a screw only accessible from under the hood. However, if you take out the center console and free up the cable end at the console control you free up an extra inch of cable. Now you can pull it out of the duct. The vacuum lines will have detached by now. The last thing is to rock the clip off the rectangular arm the wire loop is over. It won't spin off as it has a rectangular hole.
Attachment 29584
Examining it I see that it's a simple on off vacuum control that has a cam that operates a cage that a piece of bi metal fits into. The cam brings on the vacuum valve that draws on bellows in the hot water valve coming off the engine. Once the ductwork reaches the variable temperature the bi-metal bends, shutting off the draw of vacuum and the spring-loaded water switches close in unison. The the bimetal cools it allows the flow of hot water to begin again.
The switch I have has failed. I have Al looking for another. If you have a working or refurbished device please PM me. I reinstalled the unit with new vacuum lines that fit, sliding the coiled end of the cable blind and then wiggling the retainer back on was a feat, but it was a total 5 minute operation. I pulled back on the control wire and both vacuum lines until I could see the clips through the holes. Installing the screws was the easiest thing, from the inside. I put direct vacuum to the water valves and found he'll have plenty of heat.
My hand vacuum pump broke just before I finished troubleshooting. I hate it when that happens. It's only 40 years old.
I rehabbed the whole wiper system while it was apart. Cleaning them sonically in mineral spirits worked follow by a bath in alcohol, blown dry and relubricated with my wife's jewelry cleaner filled with oil.
