Kl4 had on an L4

Hello I just kinda got blown off by sure fire, i have an older L4 from about 8 years ago and lost it for about 5, my couch apparently ate it, but it has something rattling around in the kl4 head and sure fire wont touch it unless the battery life tanks or i have beam quality problems, i have not noticed any of this to-date.
any one have any ideas? i am thinking it's part of an inductor but i don't know if the head can be taken apart

there's no way to take it apart without surefire knowing. The KL4 is comprised of three interlocking pieces of aluminum serving the reflector, driver/light engine, and window threading functions. All parts are locktited and would be difficult to disassemble without strap wrenches and repeated boiling.

This will give you an idea of how it breaks down.
http://www.candlepowerforums.com/vb/showthread.php?214476-Surefire-L4-(KL4)-with-Cree-MC-E

I've dropped my L4, kicked, drop kicked, fell from a tree, from a ladder, down the chimney, lost in a bucket of waste oil, banged around in the laundry, tumble dry... never had a problem. Owned and used no less than six L4s, to this day is still my EDC. I don't recall if there was an incident involving rattle of a part inside it. The inductor is not potted, so it is possible part of the ferrite core shattered when it fell into the couch.... :thinking:

Wow , that makes me wish i had access to a machine shop, once i lost the L4 i switched to an L2 and that poor thing has been though hell and keeps on going, back when the L4 came out and i bought one my coworkers at the time made fun of me because the cost of it, until the cascade power fail we had a number of years back, I know it's old tech now but *** long as it does not eat batteries i guess i will keep it, i notice the lettering is different on the new L4 and the L2 is no longer made? i have been out of the loop

The L4 has evolved through the years... IMHP the first version is still the best beam, pure flood. The L2 was discontinued, and replaced by the LX2, which has a very focused beam as opposed to floody, but you can put a diffuser on it to fix that. I like that the LX2 is quiet... I had two L2s and they both had a high pitched whine to them!

Draco_Americanus said:

I know it's old tech now but *** long as it does not eat batteries i guess i will keep it, i notice the lettering is different on the new L4 and the L2 is no longer made? i have been out of the loop

Click to expand...

Ohhh it eats batteries, it eats alot of batteries. Good thing is the old L4 uses a boost circuit, subsequent L4s used buck circuits. Boost steps up the voltage to fuel the LuxV LED, so it can light the LED down to the minimum threshold [~2V] while the new version's can't go below the LED voltage+Chip overhead. As a result, newer lights can't use rechargeable lithium batteries like 17670 cells [linear drop with reduced output] while the old L4 will happily truck along for about 30 minutes with no distinguishable intensity between Cr123As and rechargeable lithiums.

The lettering was due to surefire's logo change, what did change was the KL4 serial. LuxV versions have an A prefix, subsequent L4s have B or C prefixes

I am willing to bet that one of the screws holding the heatsink to the inside of the head has come loose, mine had a rattle for years, after the LED died i pulled it apart and found one screw loose, and the other rattling around inside the head.
Pretty sure the heatsink not being squished down tight cooked the LED too.