Headlight Cleaning / Disassembly

[bigtowh8]

Headlight Cleaning / Disassembly
R1150RT Headlight PN: 63 12 7 680 471, New replacement cost $1400 (US)
Problem: interior side of glass has streaks from condensation. The condensation drain/vents at the bottom of the housing was plugged by an insect nest causing condensation to form on the inside of the headlight housing. Insect and nest have been removed, condensation evaporates as it should, but it left streaks on the inside of the glass lens.
I would like to clean the glass lens if possible, but I am not willing to do exploratory surgery on a fourteen hundred dollar headlight without knowing the lens and housing can be split open without damage and resealed without the use of Flex-tape or JB Weld.
I have considered using long handled swabs with alcohol, but am not sure if I have enough access through the bulb ports to clean the entire lens.
If you have experience with cleaning or disassembly with a headlight assembly, I would appreciate your input.
Thank you.
Also posted on BMW Sport Touring https://www.bmwsporttouring.com/topic/106478-headlight-cleaning-disassembly/

 

[52184]

Before I’d do any disassembly I’d try pouring some isopropyl alcohol in through the bulb opening and swishing it around, then drain and let dry. Long-handled electronic swabs might be able to reach the back side of the lens, but a simple agitate and flush is worth a try before poking around in there. The silvering on those reflectors is very delicate.

Best,
DeVern

 

[Omega Man]

I think I would try a flat cotton swab through the bulb hole before I would try any liquid. Liquid seems to have stained it.
OM

 

[lkraus]

The lens and housing are glued together with a strong, but slightly flexible adhesive. Separating them requires the use of a heat gun to soften the adhesive, and lots of gentle prying, with a very real risk of damaging the parts.

I've tried through-the-bulb-hole cleaning with various tools. It's not very effective and you can't reach most of the lens. If anyone looks closely enough to see the marks, it's pretty obvious that you tried to clean them up and failed. And yes, the silvered reflector is incredibly thin and delicate, like brittle cling wrap.

It's unlikely that the condensation marks will affect the performance of the headlight. Sometimes the best approach to a situation is to leave it alone.

 

[senseamidmadness]

The lens and housing are glued together with a strong, but slightly flexible adhesive. Separating them requires the use of a heat gun to soften the adhesive, and lots of gentle prying, with a very real risk of damaging the parts.
I've tried through-the-bulb-hole cleaning with various tools. It's not very effective and you can't reach most of the lens. If anyone looks closely enough to see the marks, it's pretty obvious that you tried to clean them up and failed. And yes, the silvered reflector is incredibly thin and delicate, like brittle cling wrap.
It's unlikely that the condensation marks will affect the performance of the headlight. Sometimes the best approach to a situation is to leave it alone.

Big agree on this one. It may drive you nuts, but with how tiny those condensation spots are it's probably not doing a thing to how well you can see.

That being said, if you insist on trying something, 91% isopropyl poured in and swished around cannot hurt and should not leave any residue. I use it all the time for cleaning electronics.

 

[51797]

I cleaned the inside of the headlight on my '03 R1100S by removing the headlight assembly and removing the bulbs. Using a weak solution of Dawn liquid detergent and some small ball bearings, maybe 4mm diameter, and rolling them around the inside of the glass for maybe 10 minutes (probably overkill). Rinsing it out several times with tap water and then with some distilled water. The difference is startling, like brand new. BB's would probably work if you have access to them. I removed the steel ball bearings with a magnet.

I found this method on a different forum.

Frank

 

[bigtowh8]

Frank,
What's the purpose of the bearings/ BBs?

 

[ramble]

Don't clean the outside so well, leave a few bugs and no one will see the spots!

 

[51797]

Frank,
What's the purpose of the bearings/ BBs?

The bearings/bb's roll around in there as you agitate the housing and "scrub" the gunk off of the inside. Use steel if you can and remove them with a magnet.

Frank

 

[Omega Man]

I guess if I was going to add anything as an “agitator” to something, it would be appropriately sized pieces of ice.
Ice has been used with reasonable success in RV fresh/waste tanks to “scrub” the sensors that are used to detect volume.
On the headlight housing, a restricted compressor blow-gun can be used to clear any water that may leave more streaks.
When it’s over, it’s just water.

OM