Now that you have the HH out what are you going to do with it? Most guys I know will go ahead and spend the money to just replace it. All that I have read says these parts can not be rebuilt. Pesonally I take that as a challenge. Here is my thinking (and again there will be plenty of you out there to tell me I'm wrong and I'm wasting my time, it's my time so deal with it) I can spend $400 on a new HH or I can waste 3 hours of my time to pull it out, redo it and put it back together. I have way more time than money and if it's bad then what's the harm.
I took the HH down to my dads house, this is where we have rebuilt a few items that we were told couldn't be done. As you can see in the pic my plunger was stuck up and wasn't coming down for anything. A lot of WD40 and a few taps with a drift and the plunger moved down. lubed it up and tapped it back up to see if it would move freely, and of course not. So we decided it was best to take it apart, and yes it can come apart very easily. The plunger must be down, do not force it too far down there is a retaining plate holding it from going too far and it's the same plate that rotates it with the gear. When the plunger is down collapse the spring and remove the 2 spring retainers. These are no different than if you were looking at the top of a valve. When those come out off comes the spring and the bottom plate. Now you can see the gear and the plunger retaining plate I was talking about. Tap the plunger up and use a drift to move it the rest of the way up if needed. The button fell off the bottom of mine and forced the plunger too far up on mine sticking it in place, that caused it to not be able to spin and therefore cracking the retaining plate into 2 pieces. You would also brake the retaining plate if you pushed the plunger too far down. Now you should have the Head, plunger, coild spring, bottom spring plate, top spring plate, 2 spring retainers, button, 3 finger spring that holds the button in place and the fuel shut off plate.
We looked at all these parts for a few minutes and I thought for sure I was going to need a new HH because of the cracked plate. However, thank to Gimp, I now have that retaining plate on the way. I was also still dealing with the fact that my plunger would not move freely in the head. Well my dad being the old Air Force mechanic and shade tree mechanic that he is pulls out a tube of lapping compound and we got to work. Using a small dab of compound and a drill we relapped the plunger into the head. If this is something you decide to do, make sure you change directions of the drill freaquently and move it up and down, do not stay in one place for any length of time. Just did it enough so the plunger is snug but movable. That plunger needs to be able to move up and down as well as spin in the head, so snug is good loose is bad. Also make sure to spray cleaner into all the journals of the plunger and the head to get any debry out of them. And when spraying into an injector port note that it will come out of the port 180* from it and it does not taste very good. When all done and all clean use some fresh oil to lube the plunger and pu it all back together. Best of luck that it will now work for you. I have to wait until I get the retaining plate from Gimp to put mine all back together and try it. If you look at the included pics on this post you can see all the parts that we removed as well as the broken retaining plate. If anyone has a "bad" HH they would be willing to send me, next I'd like to remove the set screws from one and see what's inside of it. Or maybe you want to know if this will help fix yours but just aren't able to try it, maybe I can help.
I can't tell you for sure yet that this is going to work, but I see no reason why it won't. Either way I will be sure to post more pics and results of my testing when I get the part in and get it all back together.
O-Ring Sizes:
Large O-Ring: 2.484 x .139 = -230 or 230 (depending on which standard)
Small O-ring: 2.109 x .139 = -227 or 227 (depending on which standard)
Actuator O-Ring: .426 x .070 = -013 or 013 (depending on which standard)