timing cover breather

Hi,
I bought parts a while ago to replace the breathers on my 90 TD (1990).
I've replaced both axles and two on the gearbox/transfer box, but is it necessary to drill a hole in the timing cover and fit one there? I don't do that much deep water wading, its a just in case I get caught out getting across the tidal ford on the way home!
Thanks in advance,
Jon

The timing cover has a hole in the bottom to let water & oil drain out if any gets in there, the plug for which you should fit it you are about to wade to stop water getting in and then remove again straight away. The breathers are to allow the oils to expand and contract, and there shudn' b any oil in your timing housing.

Thanks,
I know about the wading plug but I read somewhere about drilling a hole in the timing cover breather, however this did state Tdi timing cover breather. Is it different to the TD?

Not sure. I can't think why you should need to to be honest, if anyone knows then please do tell!