pneumatic headlamp adjusters.

Fri Apr 13, 2012 6:49 pm

I have the above units cleaned up, will be reinstalling them in the car even if I can't get them to work, the adjusters extend and retract with a squirt of compressed air. Can someone tell me how these actually work ? it appears to be a closed system and I can't find any reliable info anywhere. Thanks. Stephen.

Fri Apr 13, 2012 6:54 pm

you fill the lines with antifreeze IIRC, not air.

Fri Apr 13, 2012 6:59 pm

I don't think you can fill them. You buy them in one piece ready filled. Certainly that's the case with the E24. Bugger to fit too.

Fri Apr 13, 2012 9:03 pm

It's no good refilling them if you don't find and cure where they leaked in the first place, and if you do, the chances are they will soon leak somewhere else.
If you refit them in non working order, you will need to screw out the centre threaded steel rods a couple of turns or so first, to bring the correct adjustment within range of the knurled fine adjustment knob around the outside of the hydraulic cylinders.
If you want working adjusters, fit the electric units from an E34 or (with more work) an E36.

Sat Apr 14, 2012 1:27 am

Thanks for that - good advice. Has anyone had any success refilling the system ? I would imagine it's not as easy as it sounds, and I'm still unsure how it would work, there must be some pressure in the system if the strength of the return springs is anything to go by.

Sat Apr 14, 2012 9:05 am

SGP wrote:Thanks for that - good advice. Has anyone had any success refilling the system ? I would imagine it's not as easy as it sounds, and I'm still unsure how it would work, there must be some pressure in the system if the strength of the return springs is anything to go by.

I seem t remember in conversation 'HenryM3' refilled and reused the adjusters in his M3, like Brian said finding the original leak is the hardest part.

I'm sure Henry said he dismantled and submerged the assemblies in anti-freeze and reassemble all 'under water' to make sure there was no air left trapped in.

Sat Apr 14, 2012 7:19 pm

Very interesting, thanks. What were they thinking of, using a system like this ?

Sat Apr 14, 2012 7:42 pm

SGP wrote:Very interesting, thanks. What were they thinking of, using a system like this ?

It's essentially the same system as used for the brakes and the clutch, although they use better materials!

Sat Apr 14, 2012 9:04 pm

I have only ever seen this system work once !