Replacing slave cylinder issue

[Dim]

Replacing the slave cylinder, managed the old one out and new one to a point where I thinks it's in and done but it's not locking. I've taken it back out and spent the best part of a day clearing out debris and gunk from the hole and around the latches and giving it a firmer twist once it's in but still nothing. The new part and the old part look almost identical, same number and shape etc only difference being the old one had a ford logo. Before I forget to mention, it's a mk6 5 speed rwd so the slave cylinder is the external with bayonet style locking system.
Just wondering if anyone else has had this issue and what they did to solve it.

[knobby1]

Replacing the slave cylinder, managed the old one out and new one to a point where I thinks it's in and done but it's not locking. I've taken it back out and spent the best part of a day clearing out debris and gunk from the hole and around the latches and giving it a firmer twist once it's in but still nothing. The new part and the old part look almost identical, same number and shape etc only difference being the old one had a ford logo. Before I forget to mention, it's a mk6 5 speed rwd so the slave cylinder is the external with bayonet style locking system.
Just wondering if anyone else has had this issue and what they did to solve it.

There was talk years ago of "non-genuine" slaves not fitting in the bayonet lugs properly...but I've not owned a 5 speed RWD so I may be talking out my ar$e.

Lord Knobrot (Smithy)

[sentenza13]

I installed this part on my 2003 Ford 2.4.

https://fr.ridex.eu/product/8150093
Numéro de EAN: 4059191359561

and Numéro de EAN: 4059191362912