Wash with soap and water and then use a microwave steam bag.
this is what I do also, and I make sure to rinse with warm water right after I use it even if I cant steam it right away so that there is no dried up milk. I am doing this twice a day at work (third time I pump, I just rinse, put it in a ziplock bag marked "dirty", then take it home to wash with colton's day care bottles then sanitize in a microwave sanitizer which fits more than the steam bag).
This may be obvious, but it wasn't to me at first, the little yellow part pops off which makes cleaning out that section much easier! I didn't know that and never felt like it got as clean.
Yes, take off yellow part (it is really hard to get off the first time), and I use a Q tip to get in there. So I wash the whole thing in hot soapy water then a q tip covered in dish soap to get in the tiny crevices.
This is what I do too. Never found a brush small enough.
I rinse them out as soon as I finish pumping. Then at the end of the day I use a soapy nipple brush to get in there and clean it. Finally, I put all I the pump parts into the dishwasher on the sanitize cycle.
I saw a black spot in the yellow part (mold) and had to replace it and dump what I had just pumped. It was gross! Now I remove it every time, soak it and rinse it. I wish I had known i could be removed before I saw mold!
Re: how do you clean medela pump top part
BFP #1: 6.26.12 EDD: 2.11.13 missed m/c: 7.31.12 @ 12 weeks
BFP #2: 10.1.12 EDD: 6.11.13 Born 6.13.13
My two girls Flower and Ayla Faye