I would like to add a bead of silicon to the third break light on the roof of my 05 F150 reg cab (suggested by some on the forums to correct the leaking issue). However, before I do that I need to remove a dead spider and various spider parts from inside the light. Once I remove the light fixture from the truck, is it possible to separate the clear plastic outside of the light fixture from the rest of the light fixture, without screwing it up? It’s not clear to me whether the clear plastic separates from the rest of it and I didn’t want to continue to force it unless I know it comes apart.
Thanks
Mac

 

Mine didn't come apart, but I honestly didn't try to take it apart. I did use a can of CO2 ( the duster kind you use for keyboards) to clean out mine through the bulb inserts. Which silicone you going to use? I'm going to add some to mine.

 

You can buy a new led 3rd break light on eBay for about $35

 

Thanks guys.
I think I would like to try to repair it before I buy a new one.
Not sure yet what kind of silicone I'm going to use. There was a guy on another forum who said he added "a silicone sealant around the inside edge", let it dry then reattached it. If I find out what he used, I'll post it.
Mac

 

The silicone that was used by the guy on the other forum was Clear Permatex RTV Silicone.

 

Thanks Mac for the info!

 

Just let the silicone "set" before you bolt down the light fixture. If not, it will literally glue the fixture to the cab, making it impossible to remove it in the future without cracking it. Many have applied the silicone, then immediately fastened the fixture. Follow the instructions of the silicone and apply a small bead, then let it set for about 10 minutes before fastening it down.

Are you sure this is where your leak is coming from?

 

Thanks Bucko.
I saw threads that did it both ways - immediate and waiting. However, I think I'll take your advice and wait the 10 minutes. Better safe than sorry.
Mac

 

i did it and let it set 95% before i put it on. havent had a problem since. i used clear RTV also. i used a really small bead and it stayed right where its supposed to.

 

I noticed for me that I may or may not of had a leak, but the bulb was blown and debris was in the housing. My assumption was that some sort of seal wasn't working 100%.