Changed brake booster, now 4x4 and brake light are on
 

I replaced the power brake booster, check valve, and rubber hoses on my brake booster, now my brakes work as they should. But after 3 miles of driving the 4x4 and yellow brake lights came on. I'm sure it's related to the work I just did, but not sure what. Any suggestions?
It's a 2005 4.4 X5 sport with 155,000 miles, staggered wheels and a left rear tire that's been leaking for a few weeks now and I keep adding air and resetting the tire monitor system. When I changed out the booster I loosened the brake lines from clips and moved the master cylinder away with lines attached and reinstalled, never opened the system so no brake bleeding needed. I did forget to reattach the brake fluid level sensor wire to the cap before I started it and got a low fluid level warning on dash, but that went away as soon as I plugged it back in. Everything works great and the pedal is not mushy at all.
I don't have the triad of lights or the transfer case actuator gear noise, so I'm sure it's not that (had that happen a couple of times and know that noise well).
I also checked my alternator, 15V at idle.
I hope this information is relevant, just thought it couldn't hurt.
Thank you in advance.

I'd pull the codes to see what its fussing about. That way you will know what isn't plugged in. Something could of become dislodged while you were doing that.

You may have to get a BMW specific scanner or a higher price scanner than what is available at Pep Girl or the Zombie zone to see what the codes are.

Ha! Love it. I always called it "Vato Zone" :nanana:

I just replaced my brake booster, and I had to readjust the brake light switch near the brake pedal, as even a few millimetres out will cause the brake lights to stay on or not come on, or something like that; I'm not sure if that would cause the error lights you mentioned though, but it may be possible. Also, you may be able to reset those lights if the cause is now gone.

Good idea, that's something I can try. How do I reset?

Just to make sure, I removed the transfer case actuator motor and checked the gear, all in good shape still. Checked fuses, not that. How can I check codes without spending a lot on a scan tool? Do any of the parts store chains scan for free? Or how can I reset the dash lights to see if it's still a problem?

Come to Chiraq and I'll scan it for free. :popcorn:

Thanks! I'll leave now and be there in a few days.:D

Deepblonde, Thank you so much for your advice! I feel like a total idiot, never checked the brake light switch and that was it. Now I see how easy it is to accidentally change the adjustment on the switch while working around the brake pedal. Thank you!