Hello,
First i would to thanks asiekierka for responding to my last bug :
#2880
But i update buildcraft to 7.0.14 today and i have the same bug with fluid pipe :
This video was made with buildcraft 7.0.14 :
https://www.youtube.com/watch?v=H4Q0--Kjfto
As you can see the bug still here...

Well, me here on 2023 with the same problem but instead of water it is steam, restart word, change versions, nothing changed lmao.

I believe that his issue is that the liquid does not bounce back.

Intended behaviour. Pipes don't store water evenly as that causes fractional calculation bugs, and they don't spill water out because a single pipe segment only stores 250mB.

I thought you mean that you can't pour lava into a previously-water pipe... but I fixed that one as well.