I have recently purchased 3582 and had replaced the traveller lines as the old ones were becoming worn.
I have used 5mm line and replaced them exactly as the old ones were fitted, however the traveller will not cleat on either tack.
Any suggestions?

Are they long enough?

Usual mistake is cutting them slightly short.

Thanks Chris.
I have cut them to length to reduce the amount of take up before the traveller moves across. I presume that this could be the problem as I have tried to eliminate slack in the lines.
Having said that, the traveller worked quite well today at Blackpool and Fleetwood, so I am assuming that the lines/knots may have stretched/tightened, which has made this difference between yesterday and today?

It's possible.

They work better under load too, so more wind could help.

Kev, I had the same problem with mine and Chris is right, they work great in a breeze but in light stuff I have to pull them hard at the end of their travel to get them to cleat.

Thanks guys for the responses. I will have a further play around with the lines to see if I can get them to work better. Failing that, a trip to my local chandlers might be the best bet!

I just wonder if its because your new line is nice and shiny and doesn't grip so well in the cleat.  You can try gently filing notches across the teeth of the cleat that may allow it to grip the rope better.  Also if the cleat jaws are worn with old springs they won't grip so well either.  If they are the originals then they will be some way past their best.  Traveller lines need to be old tech plaited rope rather than anything fancy with a cover and a core.

Thanks Andrew for the info. All this stuff is still new to me, hence it's still a vertical learning curve!