This is the original style heater valve from a mid mileage TR6.  Note the bottom of the rivet showing at the center of the
valve, where the top and bottom are twisted together with the over lapping tangs.  This keeps it from turning itself off or loose.

Another view of the opposite side.  As you can see, the top twists off like a jar lid after the rivet is removed.

The clip on the top will have to come off, but first it's time to drill out the rivet.

I prefer to clamp things in a press vise to keep them aligned, as I hate to have a drill slip and ruin the hole size.

This requires a 1/8" or .0125" drill and come off very easily.

The rivet is out and I've begun to turn the top so you can see two tabs that held the rivet bottom from turning.

The shaft retaining clip is also removed from the top of the cover so it will lift of when released from the tangs.

You can see that it's about a 45 degree twist across the base to release all of the tabs.

Off comes the top and the diaphragm and shaft are shown in the base.  This just lifts out.

And this is the top with the lever, bushing (hidden) and the clip for the top.

And the top side before taking it apart.

These parts just slide out.

Now for the bottom of the diaphragm.

Side view, but you will see it better down the page after it's cleaned.

So here's all of the pieces ready for cleaning / plating / rebuild.

Here's the top of the diaphragm with the lid off showing what I've been told as hard water corrision.

And the bottom, with what I thought was a rind under the bottom plunger.

This view shows the bottom casting with the shaft hole for the plunger and the exist hole to the pipe which goes to the heater core.

After some discussion on 6-Pack, I decided to soak these parts overnight in  50/50 mix of CLR and water.

Bottom views of the same parts, but look at the diaphragm.

There is a spring under the plunger that was collapsed and stuck together or bound up.

I wonder if this is when these valves start to become VERY hard to close and open rather than just plain hard to open?

After a few minutes on the bench polisher, this one isn't too bad.  More on this later.

Here's the remainder of the parts after an eight hour soaking in the 50/50 CLR/Water mix.  Not too bad at all.

And this is after about five minutes of polishing on the bench polisher. 
I've got some work to do to get rid of the marks, but it will happen when I have the time.

Once I get a reply from Peter at NOS Imports, my parts will be polished, chrome plated or sent as is for their work to improve the valve.

NOS Imports aka
World Wide Auto Parts of Madison, Inc.
2517 Seiferth Rd. ­ Madison, WI 53716
Local (608) 223-9400 ­ Fax (608) 223-9403 ­ WATS (800) 362-1025