A: The plastic olives are unavailable.
You may find copper ones in B&Q or some were similar, don’t use the brass, the copper ones are softer.
If you grease the threads with silicone grease before tightening the nuts.
You then have a balancing act.............You have tighten the nuts up enough to keep the pipes water tight but not enough to split the plastic nuts.
Hope this helps!
Answered 311 days ago | The Doc