basin tap connector leak

[defender1007]

Decided to change bath taps (Trade taps) for Bristan shower mixer and basin taps (trade taps) for Bristan Quest ceramic taps. Apart from tightness of joints and difficult back nuts all went well. Fitted new 3/4" fibre washers to bath tap connectors and new 1/2" fibre washers to tap connectors. Turned on water. All ok except major leak from Basin cold tap tail connector joint. Unable to pinch up any tighter. Undo tap connecter, clean and fit another new washer. Tighten up, Major leak. Now confused. Decided to double up on fibre wshers(ie 2 washers). Reconnect no leak!! can anyone explain why other 3 taps were ok with one washer and one tap required 2 to seal.

 

[Paulus]

It happens!

 

[steadyon]

Assuming copper pipe work rather than flexi's:

a. Maybe new taps had slightly shorter threaded shanks than old, and insufficient play in cold pipe-work to make up difference. Other taps had sufficient play.
b. Put on cross threaded twice, and third time lucky (pretty unlikely).

 

[Neil K]

It's known back home in Ireland as Murphys Law, I think over here it's known as Sods Law

 

[Best]

Threads can have a tight spot on some taps & when the nut of the tap fitting locks up, you think the washer is tightened, but isn't.
Another problem is some taps have a fairly flat face for the washer to hit against, but others are designed for nuts & olives (my preference) & the washer is hitting a sharp edge.
PTFE tape can help add to the washer.

 

[tolly]

I sometimes use a bit of jet lube (jointing compound) on tap con's. Smear a bit on the ridge of the tap con, push the fibre washer down on to it, then smear a bit more paste over the top of the fibre washer before doing it up. Shouldn't really be needed but it also stops the fibre washer falling off the tap con when you knock the pipe a bit. More often than not its the pipe not being perfectly inline with the tap con that causes leaks.

 

[Best]

............. More often than not its the pipe not being perfectly inline with the tap con that causes leaks.

Good point! I always am careful the offset pipes are nice & straight into the tap, but others don't.
Also it is hard to notice if a pipe is off angle to a basin tap, as hard to see it from looking upwards below a basin.