Won't upshift
 

I'm hoping I can get some help with a problem I seem to have created.
I was fixing some leaks in my transmission, and replaced a couple of O rings on the kick down solenoid and something that looked like a heat sensing switch. I fixed the leaks but now my trans won't shift up to second. I must have done something wrong, it was working fine before. It's a 1985 380 SL.
I've taken it apart again to check that the O rings weren't damaged. Everything looks right. In checking around I found that I had no power to the kickdown switch under the gas pedal. That would suggest the fuel pump relay, but how did I get there, just changing some O rings. I've looked around online a lot and have learned a little but Auto transmissions are not my strong suit.
Thanks in advance for any suggestions.

I work on these, but what o-rings were you messing with? I looked up your car, and it says it uses 722.3xx, so here is a drawing of the transmission. Click on the drawing and it will give some numbers, so what numbers were you playing with, or took apart?

https://www.wittrans.com/parts?type=722.3

My guess is the B2 piston seal is bad, or the dog-bone was put in backwards as it is responsible for upshifts...

Martin