Rootes1725cc

Anyone know if my mk2 64 saloon should have a rear axle breather? Book says breather hole should be directly above the right hand rear lower shock mount on top of the axle. I have no such hole at all anywhere on my axle and i'm concerned as ive just replaced the diff pinion oil seal. If there's no breather surely I will build pressure in the axle and risk causing the hub seals to leak. This I don't want as ive only recently replaced the rear brake shoes.
Any advice much appreciated.

Problem solved. Breather is a 2.38mm hole located on the top of axle casing 14.2 inches from diff casing centre. Unlike the old fords which have a covered breather to avoid dirt ingress, it turns out the minx's just a drilled hole in the axle casing. Couldn't even see my hole until I ran a wire brush over the axle casing for a few minutes.