Loose parts inside KL4?

I have had minor intermittant problems with my L4, couldn't figure out why..
Yesterday I was cleaning the contact in the KL4 with an eraser, and I noticed the whole thing was moving like a loose tooth.. The contact and the black thing that houses it are both far from secure, is this easy to tighten? I see a steel ring deeper inside that seems to be slotted for removal, but I don't want to stick anything in there in case I have to send it back (I do not want to send it back), but if it's that simple, I have the tools nessasary to fix it up..
Could this be the cause of my intermittant problem?

The module that houses the driver board to which the LED and heat sink are connected to via wiring could be loose if the bezel sections aren't screwed down all the way until the module is snug in its compartment. Is there a considerable gap between the two bezel sections? I would say a gap larger than 1mm would be considerable. The KL4 can be dismantled and reassembled more easily than other Surefire LEDs. Proceed with the following steps at your own risk though:
1) Heat tap water in a pot until boiling
2) wrap KL4 in cling wrap or inside a ziploc bag with all the air removed (so that the bag doesn't float in water)
3) Immerse the KL4 while wrapped in plastic in the boiling water for 5 minutes.
4) After 5 minutes, remove the KL4 from the plastic.
5) Use two large rubber bands for grip to twist the two sections of the bezel open.
6) Once you have the bezel sections loose, you can retighten them after inspecting the threading for any obstructions that would keep the two sections from tightening properly, thus eliminating the looseness.

Here are some pictures:

That looks easy enough.. Thank you.
The part that is loose is the contact inside the head, the actuall part the battery touches, and the plastic part around it.. The gap between the two parts you have shown me seem to be the way they always were..
Are you saying I need to dissasembe this to tighten that part? If so, I will.

That silver metal ring that you are seeing inside of the head is the ground contact. If the two parts of the head came loose, then the ground lip of the body will have trouble making proper contact with the ground ring.

The first thing that you should do is to put the head on a body and make sure that you have about a .01" gap between the head and the body. If you don't and the lower portion of the head is flush with the body, then there is your ground problem. The head, when fastened to the body should contact the body at the ground ring, not the lower portion of the head.

If the head just came loose, then all you need to do is tighten it. You shouldn't need to go through any measures to "break" the factory seal, since it should be loose already.

I've worked on over 40 or so KL4s and I have noticed that a little play in the converter housing is pretty normal. The thing to check for is the gap between the body and the head.

BTW, if you do wind up needing to break the seal, I do all of my "seal breaking" in a toaster oven. 170 F usually does the trick for me. Just be sure to preheat the oven for about 15 minutes before you stick the head in there. Most ovens spike the temp at start up to get to the preset temp more quickly. After preheating, 7 or 8 minutes should do.

When you open the head up, just take care. I've seen quite a few shabby (weak) solder joints on the KL4s and some will break if you just tug on it a little.

Chop.. happy to see your input!
I will take it all apart tonight, and confirm the ground..
Hitting that switch only to hear a non lit up "click" sucks.

Yeah, take a look at it. If you're unsure, send it to me, if you don't mind the postage. I'll fit it in between mods. The KL4 is really simple and repairing them to stock form is usually pretty easy. This is, of course, assuming that the converter is in tact.

When I put it back together, assuming I can get it apart, what do I put on the threads to keep the waterproof properties?
Also, can I check the bin with it apart?

Pydpiper said:

Also, can I check the bin with it apart?

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You won't be able to check the bin because the KL4 has an emitter, not a star. The emitter doesn't have any bin markings on it, unlike a star.

grnamin said:

You won't be able to check the bin because the KL4 has an emitter, not a star. The emitter doesn't have any bin markings on it, unlike a star.

Click to expand...

Eeek.. Just when I thought I had this luxeon thing figured out..

Ok, I opened it.
As I started to unthread it (1/2 turn) I noticed a thin washer was starting to protrude from the gap, it was warped and in poor shape in general.
Once it was opened I noticed there was a greasy substance on the ground contact.
I can recall 2 specific times this head was heated up, the latest I found it beside the couch turned on, it was there a minimum of 20 minutes. Almost too hot to pick up, I put my Raytek to it, to the tune of 152 degrees. So now I am thinking the grease inside the head is a result of overheating my thread lube and it seeped onto my contacts.

After cleaning it up and leaving the broken/deformed washer out it fits tighter, the looseness in the head is gone as well.
What was the purpose of the first washer? The head now seems to function better (although I have spent far more time with this message than trying the KL4 ).
So far so good..
Thanks for the guidance.

Pydpiper said:

What was the purpose of the first washer?

Click to expand...

Um, , I figured it out..

That thin washer was the seal. There should also have been some brittle black stuff. The brittle black stuff is what used to be the sealant. The gooey stuff, also black, is what Surefire uses as sort of a potting. They just kind of pour it over the IC and the main power lead solder joints going to the lux. Some of it may have oozed onto the ground contact when they applied it to the converter. That stuff should just peel off.

If you want to insure the water tightness, I just always resealed the head with loctite. Make sure that you give the loctite a good shake before you use it and don't use too much. If you do, getting it apart again could be a real PITA. I also replace teh thin seal that they use with an appropriate o-ring. I then mount the head in a vice with protected jaws and use a strap wrench to tighten it down on the o-ring to get a good seal.

I've modified over 40 or so KL4s and I haven't had any complaints about any of them leaking.

Chop said:

I then mount the head in a vice with protected jaws and use a strap wrench to tighten it down on the o-ring to get a good seal.

I've modified over 40 or so KL4s and I haven't had any complaints about any of them leaking.

Click to expand...

Your reputation proceeds you.
This is how I got it apart..

Which loctite is appropriate?
Where do I get a new seal? Would contacting Surefire directly screw my warrany?

I just use an o-ring for the seal. All it needs to do is make contact all the way around the head. The loctite that I use is the standard blue loctite that you can get at any hardware store.

Well, after all of that I have it back together and I am happy to say it is working perfect! I have to replace a seal or two, but at least it turns on every time..
Thank you gentlemen for your perfect guidance! It was greatly appreciated!
David

deja vous, thanks chop and grnamin, hope your still at it.

Get a KX2C. I love mine.

grnamin said:

Get a KX2C. I love mine.

Click to expand...

...and how much longer before you open it up?

That head was a nightmare to take apart! I did it though, it was loaded with crud between the two pieces of the head, I suspect that was the issue.
There is no gap in those pieces now, I tighten it all the way down and it functions perfectly.
However, I need to seal it back up, I am hesitant about using loctite in case I need back in to it, how about nyogel?
It is nice to see this thing working again, thanks. Now I just need to seal it and file all the vice-grip marks out of it.

Nyogel will just lubricate the threads (and keep humidity out, of course).

You can use "blue" loctite. It'll prevent things from falling apart by themselves (which may not even happen if you tighten that thing really well), but it'll be easy to open the head if you ever need to.