Access to ceramic valve on quarter turn tap

[richard4858]

I'm baffled how to access a ceramic valve in order to replace it on this quarter turn sink tap. Here's the tap...



I can remove the arm...



...and unscrew the collar to lift it up a little...



...and unscrew the fixing plate that secures the tap to the sink...



...but I can't get to the valve because of the blob at the top, and I can't see anything else to undo.

I've tried (gently) tapping the blob off the top of the main stem from below, but it won't budge.

Any ideas, anyone?

 

[Deleted member 120897]

Have you tried unscrewing the ball (blob as you call it)? Is there a grub screw anywhere?

 

[richard4858]

Thanks for your response. I can't see a grub screw anywhere. The ball must be removable somehow but I can't see how. If it unscrewed, then I should be able to use the tap handle as a lever, and unscrew it while holding the pillar it's attached to, but it won't budge!

I'm now thinking I may just get under the sink, separate the taps from the feed pipes and just replace them, I'm that annoyed with them...