Steering screech when on full lock?

Bit of strange one this.
If i reach full steering lock there's a little high pitched screech which last for about a second then it stops.

When i ran in the engine a few weeks back, i went lock to lock a few time as advised to bleed the pump. Fluid level is spot on.
I can only think of the pulley bearing on it's way out?

Belt is loose tighten it up.

Mine usually does this after I've had the engine out, I seem to top it up but after a short while it does the same, usually dropping a bit more fluid in stops it...

Yep slight bit air locked or belt slip

Yep, belt slip.
Tightened it up a bit and job done,
Thanks

Nice easy fix ..... if all jobs were the same

haha, yes i wish