Hi guys. 
I'm just following a great thread about dismantling a seat lock. For some reason I can't get my helmet lock to work. The key turns to the left for the seat but won't turn to the right of the centre position to unlock the helmet lock. 
I've dismantled the unit but I can't take the barrel out of it's housing. Am I missing something? Should it just push out or is there a knack to removing it?
Any help would be greatly appreciated.

As I remember, the barrel can be quite a challenge to remove. Assuming you have the key able to turn the barrel to the correct position, there is a spring loaded end tab on the lock cylinder that needs to be depressed with a small bent pointed tool, to allow you to get the barrel turned completely around to the proper slot in the housing to withdraw it.
Unfortunately, that tab is up inside the housing where you can't passably see it.........if you can't see it, it's very hard to manipulate it properly to get it out if you don't know how it works. And if you don't know how it works, you'll have a tough time getting it out so you can see how it works.

I believe you have to access it through the tapered slot that the seat latch post slides down in to but I can't remember for sure & I don't have one at this time.

I think you need a pick type tool with a 90 degree or 60 degree bend of about 1/4" to 5/16" on its end and the end flattened and sharpened to a tiny chisel edge to get under the spring loaded tab & depress it.

I believe it's similar to the suitcase locks????

The way it works: 
 In the normal unlocked position.....the key slot will point at about 10 o'clock. The seat will open, but not the helmet lock.
In the locked position the key slot is straight up the seat and helmet are both locked.
In the helmet release position, The key slot points to about 1 or 2 o'clock BUT the key can not be removed.
So, turn the key clockwise to the right at about 1-2 o'clock and push the entire assy in with the key still installed, to un-snap the latch loop, then turn the key back to 10 o'clock or straight up to remove it.


I understand that this is confusing but it's the best I have. Good Luck, Ibjman

Thanks for the reply Ibjman. I've never messed with a lock barrel of any description before so it's all as clear as mud, sorry. I was hoping it was an easy ish fix but obviously not. There's a whole lock for sale on Fleabay, a bit expensive but it's the best option I suppose. Thanks again for the reply.

Be careful buying any used one. #1 the latch hook that holds the seat post down often has the "hook" broken off the end of it.
 #2 even with a used one, you still have key issues to deal with.

I assume that from your orig. post, your key will turn the barrel between position #1 & #2 but won't continue past straight up over to position #3?????

That alone seems unusual to me.......maybe you're dealing with a worn key issue?

If your near your BMW dealer.......a lot of them keep a whole big box of old worn/used keys for guys like you that need to try a bunch of different ones till you find one that works.

If you do manage to get the undamaged barrel out of the cylinder it's super easy to refit the tumbler plates to whatever key you have with only a small file. Let me know if you ever get that far.

There should be some posts & pics on here somewhere about removing the locks. Look for something about the suitcase locks......they are almost identical.

Yes, i can't turn the key clockwise from the vertical only anti-clockwise. 
I know it's something to do with the barrel on mine so if I got one with a good barrel and key I'll just use the relative bits to make a good lock if there's anything wrong with the new one, I know the rest of mine's ok. I'll have a look at the other posts about suitcase locks and see if they help. Thanks for the info

Dave G., have a look at this excellent write up from S.c.Paul.