Trouble with refill of MFC-L8650CDW

[starchild]

Hi

I have refilled my cyan cartridge for my Brother MFC-L8650CDW.

It's spilling out every print.

The toner refill I used should be the right now.

Any reason why I should get ink powder spilling out?

The only reason I can think of is too much ink powder (which I don't think so, I only filled a small amount).
OR... just the wrong powder?

Any ideas? How can I tell what the problem is?

Thanks.