Does the hakka pump wear off? I use to be able to collect 150ml while latching. Now barely 50ml. Have to manual hand express after tt.

hmmm. I think it is highly depends on whether u have let down or not. I used to collect more milk at 2nd months/ when I just started to use it. I was over produced at that time. after a while I collect lesser and has been the same volume all the times.